AudioCircle

Audio/Video Gear and Systems => Low Wattage Systems => Topic started by: -Richard- on 17 Dec 2017, 02:56 am

Title: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 17 Dec 2017, 02:56 am
I have not written in our esteemed AudioCircle forums for quite some time. I had to give up writing in the Open Baffle Forum. It seems that low-watt high-efficiency speaker open-baffle designs are not as welcome there, as they used to be. Indeed, low watt amplifiers have been relegated to the rarest of niches as strange ornaments of times past by the audio community generally. There are exceptions of course, like Nelson Pass's highly praised First Watt, low watt offerings, and excruciatingly expensive Japanese low watt tube designs.

My interest in low watt amplifiers, like my Yamamoto A-O8S 45 Single Ended Triode, began I think, out of a perverse curiosity to find out why, when I was avidly reading about audio several years ago, so many older audio enthusiasts were so vocal that low watt amplifiers can potentially deliver magic to recorded music. The idea being that a simple circuit has less chance of messing things up. In the case of a Single Ended Triode design, letting the output tubes and transformers create their magic without unnecessary interference.

About 13 years ago I began living with 45 SET tube amplifier designs to drive my DIY open baffle speakers. I owned the Korneff and Modjesky versions and also heard in my home Garber's 2A3 SET amplifier. The Korneff could not drive my then wide-range speakers adequately. The Modjesky was designed to deliver 4 watts from the 45 tube, and was quite adequate but I was concerned that the 45 tubes were driven outside their optimally comfortable parameters. The Garber 2A3 sounded slightly soft if beguiling in other respects. Then I looked elsewhere for amplification. The idea of tubes began to feel like a burden, like when I used to collect classic American cars from the late 40's and early 50's.

But eventually I went back to my interest in the 45 SET amplifier. There was something about the sound that would not leave me alone. I purchased the A-08S 45 SET Yamamoto directly from Shigeki in Japan. His U.S. dealer had retired and as far as I know no one since then has come forward to be a dealer here for this marvelous and extremely original designer.

I remembered that the Korneff 45 SET amplifier did not have enough power to drive my previous choice of OB speakers, even though they were around 92 db sensitive. So I thought why not purchase the most sensitive wide-range speaker I could find that was not shockingly expensive. I first purchased the French 8" wide-range Supravox field coil speakers. I found fussing with field coils too much trouble for me and the sound was not optimal for what I was looking for, in spite of their being well received in some areas of the OB community.

Then I turned my attention to the Lowther PM5 Alnicos, that the then American dealer claimed was 97 to 98db sensitive, although the Lowther website gives them a lower rating. They are 16 ohm speakers, so I had Shigeki install 16 ohm output transformers in the A-O8S following Don Garber's personal recommendation. The Lowthers have since lost their US dealer, due to some conflict of interests, which is unfortunate. What drew me to the Lowther was their design first, then their sensitivity.

I was using NOS 45 tubes that I frankly loved for several years. Then this year I ordered EML Mesh Plate 45's from Jac in Germany. It was Jac who recommended the Mesh Plates over the Solid Plates for refinement and transparency.

Although I enjoyed what the Mesh Plates were doing for the music I felt that something was missing compared to my best pair of RCA NOS 45 tubes. Then about 2 months ago I re-discovered an old pair of Nordost flat speaker cables. I was a little concerned about their revealing nature, the Lowther's could spotlight the upper frequency region with components that lacked synergy with it. But after listening for a few days I was quite stunned realizing that the EML Mesh Plate 45 tubes had come fully alive.

So now I am hearing what I have been looking for since I began a 13 year journey into low watt, actually 2 watt, SET tube amplification and high sensitivity speakers. The music sounds alive, incredibly present, transparent, dynamic and realistic. Deborah and I are very happy with this set up. I am using the LightSpeed Attenuator, designed by George Stantscheff in Australia, as a passive preamplifier, so there is no preamplifier gain. What is entirely unexpected is that the A-O8S Yamamoto without any preamplifier gain plays surprising loud, and on rare occasions I do let the music rip for fun. My simple Open Baffle speakers, a slab of plywood with holes in it mounted on a plinth, helps to integrate the Lowthers with the room and create the illusion of space.

Now I would like to share a few simple tweaks with our Low Watt community. I am using Spotify which I pay $9 month for, which gives Deborah and I access to thousands of possible musical choices allowing us to explore music that we would never be able to find without extensive research. I am streaming the music through an iPad mini, which incidentally, I did not originally purchase for this use, so admittedly the DAC in the iPad Mini may not be optimal, which suggests that a great deal more refinement and resolution can potentially await us if I can find a low price DAC that works nicely with it. When in Spotify select the symbol icon on the top right side that looks like a flower-like button. A new page opens with a list of choices; select Musical Quality, then Extreme. That will allow access to 320 kbits resolution when it is available. Then select Playback; a new page opens, select Equalizer. A simple yet effective equalizer appears that lets you move white dots above a choice of 6 gamuts @ 60, 150, 400, 1k, 2.4k and 15khz. A green line connects them helping you to see how your 'chart' looks. There is a list below the eq chart, Accoustics, Bass Booster, Classical and several other selections that will show you what the Spotify engineers think works best with these musical styles, a handy reference to play with.

I realize that my choice of media is not optimal. These days if one reads Stereophile, they are pushing LP's which have proved extraordinarily resilient as media, and there are hundreds of dedicated DAC's and streaming components that promise high resolution; the newest format for digital streaming being MQA, which several streaming services now offer, including streaming components that are designed to unpack it.

But for now, what I am hearing with my 2 watt SET 45 amplifier and 97db sensitive wide-range speakers, using Spotify streamed through a simple iPad Mini can be quite thrilling.

Wishing Everyone Beautiful Musical Experiences and Everything Wonderful for the New Year. With Warmest Friendship ~ Richard
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Bemopti123 on 17 Dec 2017, 03:46 am
Welcome back Richard.  It is most often that people such us here tend to mix passion for the technical aspect of musical reproduction rather than the performance, which should be supreme when it comes to audio.  It seems to me that you found the right balance between passion for equipment that delivers the performance that you most expect. Who cares about people who spend grandiose amounts of $$$$ in order to extract that last iota of sonical performance? I say as long as enjoyment is present and kicking, that should be the barometer of our audioquest. 

Even though I have invested $$$$ in equipment, as of late, I have gotten very little listening time from the setup.  Performance and convenience trumps technical prowess.  I say rock on with your system.   :thumb:
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Wind Chaser on 17 Dec 2017, 10:32 am
Hey Richard,

How's it going? You wouldn't believe changes I've made to my system since we spoke earlier this year. The Coincident was a great amp and it gave me many immensely pleasurable hours; but it's gone and I do not miss it! I've began a new journey and it already feels like I have arrived... :lol:  :D

I too am using an iPad with an Auralic Aries Mini to stream some amazing radio stations from around the globe, some in high def. Like you say it can be quite trilling. It all makes me wish I was 18 again. None of this stuff was available back then. This is a great time to be into this hobby.  :thumb:
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: roscoe65 on 17 Dec 2017, 03:00 pm
Welcome back.  I am also toying with the design of high efficiency, open baffle speakers but am dealing with room constraints.  My amps and driver are different, but the principles remain the same.

As far as streaming choices, I use Tidal lossless streaming to a Chromecast Audio to my DAC via optical.  I have access to 46  million tracks at CD quality (albeit often remastered) for a discounted rate of $8/month.  I am on the verge of adding Roon, but as of the moment Tidal is the only streaming service that integrates with Roon, and there are recent rumors of Tidal running out of money.  If that happens I will shift over to Deezer until Spotify offers lossless, hopefully with Roon integration.

Streaming - even lossless - may not provide the same ultimate sound quality as vinyl or high resolution local files, but at this point in my life I do not wish to deal with hundred or thousands of pieces of physical media.  Streaming Tidal to my Schmitt Bimby, 421A amp and Omega speakers sounds at least as good as my similar system from over 20 years ago (California Audio Labs Delta/Alpha, Rankin Bugle direct coupled 45 SET, Cabasse 94dB 8” two-ways, Muse Model 18 subwoofer).
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Jon L on 17 Dec 2017, 06:06 pm
As far as streaming choices, I use Tidal lossless streaming to a Chromecast Audio to my DAC via optical. 

It's puzzling to me that in almost 2018, there is so few choices in solid, low-cost streamers that offer coax spdif output. 
Like most audiophiles, I already own high end DAC's and would like a good streamer that has good coax spdif out.  If no coax, would take regular toslink preferably over mini toslink, and analogue outputs are not needed. 

Looking around, I might just have to pick up Chromecast Audio unless there are better options.. :scratch:

Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 17 Dec 2017, 06:10 pm
Welcome back Richard :thumb:
I appreciated your advices when I was new here, thanks a lot.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: belle harbor on 17 Dec 2017, 09:18 pm
I have not written in our esteemed AudioCircle forums for quite some time. I had to give up writing in the Open Baffle Forum. It seems that low-watt high-efficiency speaker open-baffle designs are not as welcome there, as they used to be. Indeed, low watt amplifiers have been relegated to the rarest of niches as strange ornaments of times past by the audio community generally. There are exceptions of course, like Nelson Pass's highly praised First Watt, low watt offerings, and excruciatingly expensive Japanese low watt tube designs.

My interest in low watt amplifiers, like my Yamamoto A-O8S 45 Single Ended Triode, began I think, out of a perverse curiosity to find out why, when I was avidly reading about audio several years ago, so many older audio enthusiasts were so vocal that low watt amplifiers can potentially deliver magic to recorded music. The idea being that a simple circuit has less chance of messing things up. In the case of a Single Ended Triode design, letting the output tubes and transformers create their magic without unnecessary interference.
hard

It is gratifying to encounter someone who has experienced the joy of flea power.  There's a whole world of magic to be encountered in the world of single ended tube amps capable of delivering 2 watts or less (both triode and pentode) in combination with very high efficiency speakers (especially if the latter are used in a near-field arrangement).  Like everything else in audio, it's a matter of individual taste; and, many just can't accept that a 1 watt amp can play more loudly and cleanly into a high efficiency speaker than a 100 watt amp into a low efficiency unit.  I do many demonstrations of the former and never disclose details to listeners until after they have had a chance to experience the sound.  The look of pure astonishment on their faces when they find out they were listening to flea power is worth the effort. 
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: roscoe65 on 18 Dec 2017, 01:04 am
It's puzzling to me that in almost 2018, there is so few choices in solid, low-cost streamers that offer coax spdif output. 
Like most audiophiles, I already own high end DAC's and would like a good streamer that has good coax spdif out.  If no coax, would take regular toslink preferably over mini toslink, and analogue outputs are not needed. 

Looking around, I might just have to pick up Chromecast Audio unless there are better options.. :scratch:

While it isn’t coax SPDIF, the Nvidia Shield TV outputs high resolution via USB.  It’s currently selling for $149.  With the recent news that Deezer will support Chromecast, you would have at least two FLAC services to choose from.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: ohenry on 18 Dec 2017, 02:08 am
I have a few flea amps and really enjoy them.  I bet there are many of us lurking with sweet and simple tube amps (maybe not as nice as Richard's  :green:).

BTW, if you want to try a cool speaker that's cheap and easy to make, grab a set of Saba console greencone drivers (woofer and tweeters) from the 1950's.  I have mine mounted in simple floorstanding, open-backed plywood boxes using one cap for the tweeter crossover.  They are efficient and sound great with sane decibels.  I got mine from a German guy on ebay and they are in excellent condition.  I suppose it makes perfect sense they get along well with low power tube amps.  :D

I have three Chromecast audio units streaming Tidal hifi.  Again... another good sounding, cheap thrill.  I bought some decent 3.5mm to RCA plug ICs on Amazon and it's fun to sit back and dream of different music to play.  It's a nice way to discover/investigate music before investing in vinyl or CDs if you're like me and addicted to tangible formats.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 18 Dec 2017, 07:36 pm
Sorry to hear that you are not able to spend more time listening to music, Bemopti123, which everyone in our audio community knows sustains a vital sense of being connected to life and the mystery of deep 'listening'. I have my audio set-up in my main 'living space', which also serves multiple purposes. Also my painting studio and Deborah's studio are open to this 'living space' so I can play the music even while we work. I am fortunate that Deborah loves music at least as much as I do and was even responsible for my continued interest in low watt SET tube designs. She finds most solid state amplifiers agitate her. When I listen to music 'directly' I sit off-axis reclining on a couch. This is one of the unique benefits of Open Baffle speaker design, the presentation penetrates the entire room, allowing for the luxury of off-axis listening pleasure without necessitating having to sit in front of the speakers. I hope you can get back to your listing pleasure soon.
---
What have you replaced your Coincident amplifier with, Wind Chaser? The Aurarlic Aries Mini is highly regarded, a nice set-up indeed! Of course you are spot-on, this is really a wonderful time to be involved with audio.
---
Tidal is probably the best streaming service available right now, roscoe65. How interesting that you are using Chromecast Audio: https://store.google.com/product/chromecast_audio I have never heard of it before. How did you manage to get a discount on Tidal for only $8 per month? That is a lovely deal! Tidal is running out of money? How strange, it sounds like their must be some problem with their business model. Tidal is the premier streaming service that every audio reviewer is in love with. Yet, and this is peculiar, I tried it during their introductory free month and found it sounded lifeless on my audio set-up. I think using the built-in EQ on Spotify can add juice to the music. And it may be that 'juice' that is creating the special dimension that the music has in Spotify that lends itself to my set-up. However, I should revisit Tidal again when I have the chance.

You are quite right about the limitations of streaming. When I hooked-up my CD player a while back I was shocked at how much musical information it allowed compared to streaming; it was also wildly more dynamic, stunningly so. However, my current set-up is so revealing that all of the warts came through as well from this admittedly low-end CD player; there was a significant lack of refinement that I could never live with, a certain crudeness that accompanied the presentation. I would have to invest in a very sophisticated CD player to get the incredibly dynamic presentation without the noise. Something beyond my present budget. The lack of 'noise' allows Spotify streaming to sound remarkably transparent, something I crave and because of it, the music sounds more like it is coming from an electrostatic speaker.
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I had to look up S/PDIF (Sony/Philips Digital Interface Format), Jon L, "The signal is transmitted over either a coaxial cable with RCA connectors or a fibre optic cable with TOSLINK connectors." Can you share with us what advantages this has over standard RCA interconnects? Also, what would be the advantage of Chromecast Audio over streaming Spotify from an iPad?
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Thank you FullRangeMan. I like your idea of no crossovers and (apparently) no tweeters. Keeping things simple really works for me.
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Nice insight, belle harbor; it seems that as solid state amplifier designers were delivering amps with more and more watts, speaker designers got a little lazy and moved away from working with high-efficiency speakers. Admittedly, there are serious problems designing with high efficiency speakers. My own system using a Lowther Alnico driver played 'full-range' but augmented with a 15" bass speaker which cuts off at around 250Hz and having its own dedicated amp, is no where near 'perfect'. There are anomalies that appear from time to time. I am certain the frequency gamuts are not flat through the entire range, for example, as I use the EQ on Spotify to enhance certain frequency gamuts. Although there is a great deal of work done by speaker designers to flatten the frequency response of their speaker designs, it is not entirely clear if this is ideal. For example the classic BBC speaker design used a 'bump' in the lower gamut, somewhere around 250Hz, I think, to create 'warmth' in the presentation. As you said, it is a matter of individual taste. It also depends on what kind of music one listens to most of the time. Deborah and I love small scale ensemble classical music from every period, including jazz and especially the great women jazz singers, like Holiday, Vaughn, Horn, Gardot, Fitzgerald, Simone, Wilson, Washington, and so many other magnificent singers like Sinatra, Baker, Cohen, Lennon and Mathis. It is a trade-off I am willing to accept for the 'magic' of what the system gets right, wonderful detail without any etching, deep saturation of musical color and texture, and a nice dose of ambient 'space'.
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Nvidia Shield TV is also new to me, Roscoe65. I have not watched TV for over 40 years but Deborah and I are filmophiles and share a love and passion for film. Can you share with us something about it?
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I can see your love for 'tangible' media, ohenry, although my budget for all things related to audio and music has shrunk over the years. And of course tangible media needs well designed players to sound at their best, another major expense. I can see why vinyl has such a renewed resurgence over the past 10 years, I love the feel of LP's and handling them has its own charms. However, I also remember trying to poise the needle over the subtle 'empty' grooves between songs, or parts of a sonata in order to just play that section; rather time consuming, requiring great care. There are many drivers from the 1950's that have never been bested! Really, a golden age for audio. My first audio system used a pair of open backed boxes, each with a single Wharfedale coaxial driver, driven by a tube receiver. Essentially, an Open Baffle design. How I loved that sound! That early system enhanced my love of music and broadened my musical tastes and enjoyment beyond measure.

With Warmest Friendship ~ Richard


(http://www.audiocircle.com/image.php?id=172990)  (http://www.audiocircle.com/image.php?id=172991)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: rollo on 5 Jan 2018, 05:17 pm
 Nice system Richard. I joined the party with Rethm Saadhana 102db wideband speakers and Dennis Had SET [5w]. PP I use an Audio Hungary A20i integrated.


charles
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 6 Jan 2018, 08:18 pm
Hi Charles ~

I cannot think of a more sophisticated design than the Rethm Saadhana, or a more sophisticated hi-end audio designer than Jacob George in India. He is a US trained architect and his design studio in Kerala is quite superb looking! He started with Lowther drivers but his work-around issues trying to tame the British driver to fit his cabinet design led him to start fresh with his own completely redesigned drivers. Now that is a true high-end uncompromised design approach. I would love to hear your system. Nice!

With Warmest Friendship ~ Richard
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 6 Jan 2018, 11:18 pm
Wow very nice Yamamoto :thumb:
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: rollo on 24 Jan 2018, 05:54 pm
Hi Charles ~

I cannot think of a more sophisticated design than the Rethm Saadhana, or a more sophisticated hi-end audio designer than Jacob George in India. He is a US trained architect and his design studio in Kerala is quite superb looking! He started with Lowther drivers but his work-around issues trying to tame the British driver to fit his cabinet design led him to start fresh with his own completely redesigned drivers. Now that is a true high-end uncompromised design approach. I would love to hear your system. Nice!

With Warmest Friendship ~ Richard
Thanks Richard If you are ever in NY give me a ring, come over and enjoy some tunes and a home cooked Italian feast. Yes Jacob driver is something to behold. With built in sub to 20HZ and no crossover oh my !!

charles

charles
   Richard if you ever in NY give me
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: doggie on 30 Jan 2018, 03:54 am
It's puzzling to me that in almost 2018, there is so few choices in solid, low-cost streamers that offer coax spdif output. 
Like most audiophiles, I already own high end DAC's and would like a good streamer that has good coax spdif out.  If no coax, would take regular toslink preferably over mini toslink, and analogue outputs are not needed. 

Looking around, I might just have to pick up Chromecast Audio unless there are better options.. :scratch:

An older Apple TV has optical out. I use one for Pandora but I am considering moving to Tidal. Does Tidal have a good collection of Classical and Jazz?
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: rockdoc on 27 Feb 2018, 03:05 pm
Great post, Richard. I really appreciate your discussion of the various amps you've heard; Yamamoto, Garber, and Korneff, as I'm looking around trying to figure out my next build or maybe purchase. Right now I'm running a pair of Bottlehead Paraglow parafeed amps I built and set up for the 45s many years ago,  and they are truly magical. I'm thinking I need to experience some of the other 45 tube amp circuit flavors out there. I'm also fascinated with high efficiency open baffle speakers, suitable for the 45 amps, so I'll be looking through your previous posts for what you've done there. Yes, for better or worse, we are "relegated to the rarest of niches as strange ornaments of times past" but personally, I'm fine with it.

Steve T
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: rockdoc on 27 Feb 2018, 05:35 pm
-Richard-, I saw in another of your posts mention of the Bottlehead Stereomour amp. Did you ever get a chance to listen and compare this with the Yamamoto, Korneff, Garber Fi etc? That Stereomour II set up for 45s might be my next build.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Tyson on 27 Feb 2018, 07:12 pm
I would LOVE to use a 45 amp on my speakers.  I'm trying to figure out how to get hum reduced in my system, right now ALL tube amps are problematic.  But if/when I get that sorted, I think 45s would be pretty great on my planar magnetic OB Serenity Acoustic Super 7's, since they have active bass/sub and planar magnetic mids/highs that only go to 200hz or so and have a super flat impedance over that operating range.  Seems like they would be an ideal match for these types of amps. 
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: roscoe65 on 27 Feb 2018, 07:22 pm
An older Apple TV has optical out. I use one for Pandora but I am considering moving to Tidal. Does Tidal have a good collection of Classical and Jazz?

I'm moving away from Chromecast due to performance issues.  While it will stream, it definitely is not up to our expected standards.

I'm about to implement an Allo USBridge.  It is a higher-performance Raspberry Pi board with a low-noise USB tophat.  preloaded software allows users to stream Roon, Airplay, and DNLA.  Total cost is less than $200 shipped.

Allo also sells the Digione Player, which is the same thing with SPDIF output.  https://allo.com/sparky/digione-player.html
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 17 Mar 2018, 11:18 pm
I apologize for not responding earlier. I seem to have been busier than normal lately, but I am happy to say that during the past few weeks I have made some fundamental changes to my system, all of which resulted in an extraordinary leap in performance.

My nephew decided to gift me with a 2010 used mac mini. He has been using it for his own streaming and thought it was time I updated my system. Hooking up the mac mini by itself did not yield better performance than my ipad mini, and Spotify does not provide its simple EQ software for computers, a strange decision on their part, it is only available for mobile devices, so that caused me to plunge into doing a little research into an external DAC that would raise the level of performance for streaming media. Since my budget, such as it is, is minimal, and I wanted to experience MQA, that many reviewers were toting as a high resolution streaming solution, I quickly came to see that there are currently only 2 DAC's that fulfill that niche in this low price area.

I realized that it was time to try Tidal, so I signed-up for their free 30-day trial. The MQA files streaming through Tidal did sound punchy but not refined. During my research I came upon the 'bit-perfect' software of Audirvana and decided to give that a try. You can sign-up for a 2 week free trial with them.

The 2 choices of DAC's came down to the Dragon Fly Red or Explorer2, both sell for $200, a very modest investment. There are several internet sellers that give you 30 days to try either one, so I thought that would give me enough time to decide if this price-point for a DAC really made a difference in performance. I decided on the Explorer2 for a few reasons, one being that Meridian engineers are the designers of the MQA coding scheme, so I thought that their uncorking of the embedded MQA code would be well implemented, although the DFR also now has that option. Some users that have both felt the Explorer2 a little more musical than the DFR which they felt is better for mobile audio devices and the Explorer2 has a little higher resolution capacity.

So I hooked up the Explorer2, streaming Tidal through the bit-perfect software of Audirvana and was truly shocked by the musical performance. My open baffle system uses 2 drivers for each panel, and each driver has its own amplifier. That necessitates splitting the signal at it leaves the Explorer2 DAC. I was using 2 generic cables for that and I felt that they were hindering the performance so with a little research I decided on AudioQuest Big Sur Interconnects, 3.5MM to RCA, 0.6 Meter @ $100 each. Yes, I know quite a splurge for a tight budget. But as soon as I replaced the generic cables with them the performance leaped into a dimension of refinement and surreal quiet as well as ambient spatial presence. I also used the AudioQuest Flexible Mini Adapter Male 3.5 Mini to Dual Female 3.5, @ $16 which provided the split from the Explorer2.

With everything working together there is now an 'ambient' otherworldly quiet pervading the musical space, textures never heard before leap out of instruments and voices, the treble region is now highly resolved and transparent, and the most important factor for Deborah and I, we are easily pulled into the sublime almost hypnotic seductiveness of every well recorded CD we stream. The sound immediately reminded me of my LP playing days, a sense of analogue plumpness with rich overtones. Also, with the EML Mesh Plate 45 tubes the bass reached down to levels I never heard on my system before, articulate, room shaking and completely unexpected.

Audirvana is $74 for a one-time download of its app. But they also have a deal whereby you can sign-up for Tidal for a 3 full months free trial. If you sign-up for Tidal's free 30-day trial first and then through Audirvana sign-up for the free 90-day trial, you are getting Audirvana for $60 off their $74 price of admission (Tidal is $20 a month x 3 months = $60). So the cost of Audirvana comes down to just $14, quite a deal.

Audirvana creates magic with Tidal. Tidal by itself was disappointing to me, especially on CD resolution files of 16/44.1kHz. But streamed through Audirvana, the stream sounds like analog media, rich, clean, highly articulate, detailed and on my system, magical.

Now let me warn everyone interested in trying Audirvana and Tidal, to see if it hopefully helps your streaming experience. Tidal demands that you use an email address that you did not previously use for their 30-day free trial when signing-up through Audirvana for the 90-day free trial. I had originally signed up for the 30-day free trial through Deborah's email so I naturally used my own email address for the 90-day trial period. It would not work, because, as it turned out, I had perhaps a year ago already signed up for their 30-day free trial but had forgotten that I did. But Tidal does not raise a dialogue-box to inform you of that. Instead it simply does not work. I wrote to the Tidal staff to help me resolve this dilemma and they also did not 'see' that I had previously signed-up, so they said go ahead and keep trying. I also asked the designer of Audirvana, Damien Plisson, for help, and he was very accessible and easy to chat with through email. Finally I used an alternative email and everything worked fine. Tidal does have an option for paying for a year that reduces the monthly amount a little.

As it turned out, the resolution and magic of ordinary 16/44.1kHz files sounds as good as MQA files through Audirvana. So in a very real sense I did not necessarily need to purchase an MQA-ready DAC. However, I like what the Explorer2 is doing for the music and at this time feel no need to change DAC's.

The amount of CD's available through Tidal is quite astonishing. Sometimes it takes a little trial-and-error to navigate through Audirvana's search box to find a CD or musical genre, but it is well worth it, and you will be rewarded with a plethora of wonderful CD choices.

I would like to address some of the interesting posts since I wrote last, and I will a little later.

Ojai is getting the much needed rain that we crave, especially after the devastating Thomas fire that burned up most of our mountain foliage. Rain is a blessing we never tire of in this chaparral desert region.

With Warmest Friendship ~ Richard
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: seikosha on 18 Mar 2018, 09:03 pm
I would LOVE to use a 45 amp on my speakers.  I'm trying to figure out how to get hum reduced in my system, right now ALL tube amps are problematic.  But if/when I get that sorted, I think 45s would be pretty great on my planar magnetic OB Serenity Acoustic Super 7's, since they have active bass/sub and planar magnetic mids/highs that only go to 200hz or so and have a super flat impedance over that operating range.  Seems like they would be an ideal match for these types of amps.

Take a look at the Quicksilver Horn Monos.  They are specifically designed to be quiet with high efficiency speakers.  First tube amp I’ve had that is completely quiet...and it sounds great too.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 18 Mar 2018, 09:36 pm
I liked this Quicksilver Horn very big power transformer,
somewhat unusual today due cost saving.

Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: tybee on 18 Mar 2018, 11:08 pm
Richard,

You and I have exchanged emails in past years as you were beginning your journey to Yamamoto.  I recently purchased a Yamamoto clone from Oliver Sayes equipped with RCA 45s, an 80 RCA rectifier tube and the standard 717as and I must say this amp is an ear and eye opener.  Although my clone is still burning in, it already displays the clarity and dynamics that reviewers talked about back in 2005 or so for the Yamamoto, and I am very sorry that I waited so long to give a try. Kevin of Glow in the Dark tube amps turned me onto the 80 rectifier which Decware fanboys are currently jumping on for Decware amps.

For those listeners who enjoy true DHT systems,  a Yamamoto (original or clone) with efficient speakers, a passive preamp, and new or old audio sources (Computer, CD, Tape, Vinyl) can enjoy music as it should be heard and enjoyed.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Rocket_Ronny on 18 Mar 2018, 11:22 pm

Hi Richard.

Your original post about your journey has my respect.
Good for you.


Rocket Ronny
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 20 Mar 2018, 03:43 am
Hi rollo ~ Deborah and I always talk about re-visiting New York. I grew up in Brooklyn and Deborah in Long Island. We lived in NYCity for many years and loved it before finally moving to Ojai, California. I will definitely call you if we visit NY, an Italian feast combined with the Jacob speakers is unbelievably irresistible. Thank you for your kind offer!!!

Hi doggie ~ Tidal is quite amazing for musical choices. I play Tidal through Aurdirvana. Deborah and I listen to mostly classical and jazz. If you have a chance try Jerry Mulligan Meets Ben Webster, and, Bach: Three Sonatas for Viola da Gamba and Harpsichord, Glen Gould (who actually plays piano on this disc) & Jaime Loaredo, also Saman by Hildur Gudnadottir, for aural thrills.

Hi rockdoc ~ Your Bottlehead Paraglow Parafeed 45 amps must surely be 'magical'. Nice! Perhaps before discovering your next amplifier build or purchase you may want to try a DIY open baffle speaker design. Here are my primary reasons for suggesting it: Drivers in open baffle configuration have no 'resistance' to have to work against, the bane of box speakers, so they communicate a wealth of sonic detail and texture. There are no, or few room nodes stimulated that can create problematic reflections. The sound is richly room filling with a spaciousness that will make almost all box speakers sound overly directional by comparison. They are easy to build with simple tools. You can choose from a nice selection of high efficiency drivers. The investment of drivers is not limited to one DIY open baffle design, you can always reconfigure the design as you learn more about what 'sound' you are after. Lastly, I learned more from building my own open baffle speakers than from listening over years to hundreds of 'commercial' designs, a nice often overlooked pay-back for the time spent in the DIY efforts. Deborah will never give up our open baffle speakers, after living with them for the last 14 years she can no longer tolerate most commercial speaker designs.

Hi Tyson ~ Sorry but I have never had a chance to listen to the Bottlehead Stereomour amps. I am almost certain I would fall in love with them. To my thinking you cannot go wrong with this circuit design. Here are the simple reasons I opted for the Yamamoto A08S: Shigeki designs the Yamamoto A08S with a powerful output stage, this 2 watt amplifier is so powerful that I rarely use more than 1/4 watt for most room filling music (room size 20' x 30' with 8' ceiling) driving my Lower PM5A Alnico/Ticonal driver (97-98db depending on who is measuring it) and I only use a passive preamplifer. Since the Lowthers are 15 ohm I had Shigeki install a 16 ohm output transformer on the recommendation from Don Garber of Fi (his recent death is a great loss, you could call Don and chat SET audio with him). Also Shigeki designs and builds his own C-style transformers, one of the best in the world. Almost all of the components in the A08S are built by Shigeki in his laboratory. The design never falls to fill me with a sense of deep appreciation and aesthetic pleasure. And lastly, the rate of exchange when i purchased the amp 3 years ago, favored the dollar, making the A08S at least $500 to $600 cheaper than previously. The cost was around $2500. Some knowledgable SET lovers think the amp should cost $20,000 owing to its parts and being hand built.

Hi Tyson ~ Have you tried getting rid of the 'ground' plug? Sometimes this works magic when there is hum.

Hi tybee ~ Yes, I remember our conversations. How lovely you were able to purchase a 45 based on a similar circuit to the A08S! Congratulations! I also use a passive preamp designed by George Stantscheff, his Lightspeed ('This revolutionary device uses an optocoupler device in a sealed unit, which consists of a high performance LED that shines on a light dependent resistor (LDR). This means that it is a passive preamplifier with no contact points in the form of a "wiper" as in the case of a potentiometer or "switches" like a discrete stepped attenuator. It provides a totally new and revolutionary way of controlling the source volume, like plugging the fixed output of your CD player/source component directly into your power amp, yet having control over the volume. It allows the most transparent dynamic transfer of signal from the source to the power amp'). I do not want to ever use an active preamplifier if that can be helped. I tried several preamplifiers with SET amplifiers and found that they all took away the glorious rich textures, ambient space and dynamic presence that is a good part of the SET magic. The problem I had with the Korneff 45 was that it apparently needed his or a similar tube preamplifier to play the German 94db drivers I was using in OB at the time. It seemed to have insufficient power for my set-up and room.

Hi Rocket_Ronny ~ Very kind of you to share that with me. Thank you.

Our little community of music lovers is here to share and help each other to make informed decisions and also to share our enthusiastic love of music beautifully rendered with low watt gear.

With Warmest Friendship ~ Richard

Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: rollo on 20 Mar 2018, 04:59 pm
Hi Richard yes, Rethms and pasta do seem to go together very well. Especially when accompanied with wine.Love yo have ya.

charles
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: rollo on 20 Mar 2018, 05:03 pm
BTW Richard I agree 100% using a passive with SET. The low input sensitivity of the SET Amp are perfect for passive use. Only need active for phono IMHO.
  I like the Stevens and Billington transformer based passive. Music first that is. Prefer over LED based so far.


charles
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 21 Mar 2018, 07:23 pm
Hi rollo ~ Your Stevens and Billington is probably the best passive preamplifier made. For anyone interested in finding out more about this audio masterpiece here is a link to Srajan's 'review': http://www.6moons.com/audioreviews/musicfirst/passive.html  There is even a +6db option if I remember correctly, which I thought I might need. As it turned out the 2 volts of streaming media plus the A08S strong output is all that is needed. As an additional piece of gear for maximum efficiency, I suppose a low impedance cable is probably mandatory.

I definitely wanted to own the TX-102 (now the TX-103). However, when I was researching for the best passive preamplifier for small watt SET amplifiers, it was $2500. I just could not swing it. I don't know if the price has changed. Thanks for bringing the amazing TX102/103 to my and everyones attention. A used Stevens and Billington could work nicely as an alternative to the much less expensive, at $500, Lightspeed.

Hi Charles ~ Your kind and thoughtful offer is now emblazoned in my mind. My mouth and ears are drooling.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: bopnote on 11 Mar 2019, 04:31 pm
WOW!

I know it's been a while but these posts have really informed me.

Thanks   :)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Bumpy on 9 May 2019, 12:01 pm
Hi rollo ~ Your Stevens and Billington is probably the best passive preamplifier made.

I owned the TX102. It may be the best made but its not the best sounding :)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 9 May 2019, 04:55 pm
Hi Bumpy ~

"I owned the TX102. It may be the best made but its not the best sounding"

What other components where you using? Also what did you go with after the TX102 (passive or active) hat sounded better?

Warmest Regards ~ -Richard-
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Tyson on 9 May 2019, 06:24 pm
I would LOVE to use a 45 amp on my speakers.  I'm trying to figure out how to get hum reduced in my system, right now ALL tube amps are problematic.  But if/when I get that sorted, I think 45s would be pretty great on my planar magnetic OB Serenity Acoustic Super 7's, since they have active bass/sub and planar magnetic mids/highs that only go to 200hz or so and have a super flat impedance over that operating range.  Seems like they would be an ideal match for these types of amps. 

I got my hum issues sorted (mostly using a PS Audio P5 to sort my dirty power issues).  I now run a TAL Korneff Type 45 amp in my downstairs setup with my Super 7s, occasionally switching to a pair of Dennis Had 'Inspire' SEP monoblocks.  I really love the sound of single ended circuits with my high sensitivity open baffle planars.  Just magical.

I had a family friend over for dinner 2 nights ago, we fired up the downstairs system, put on some Ella and Louis Armstrong.  She said "I feel like I'm in a smoke filled jazz night club."  That was pretty awesome.

I told her next time we'll have to fire up the big screen projector and watch an old Chaplin movie, which is equally astonishing.  Having a great projector plus the SET/Planar OB speakers has really opened up a whole new world re: cinema, too. 
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: mashaffer on 5 Aug 2019, 01:07 am
If I might add a bit about my journey...

After my initial childhood system most of my stereos have been 35to 50 wpc solid state receivers from the 70s and 80s. I developed interest in vacuum tube electronics so I built a SEUL KT88 amp and have paired it with some OB speakers that I made. I have been quite taken with the clarity of sound and the "they are here" sound stage. This has piqued my interest in true high efficiency low power systems. A friend at work who's experience in audio is primarily in the megawatt car stereo arena can not even fathom single digit power output (I estimate mine is around 8wpc max).

My speakers are not really highly efficient but my small listening space helps (though listening from the next room is still quite doable). The speakers are made in the form of a knick-knack table such as one sees used to hold a phone in old movies and 50s sitcoms. It uses a 4" (really closer to 3" due to large plastic mounting ring) Mark Audio CHR-70 as the main driver with a 10" Goldwood OEM (high Qts) helper woofer. The MA driver is a really nice smooth sounding but detailed driver IMO but is not all that efficient. Even so I had to pad it down a bit to match up with the woofer. I have kludged together a subwoofer to use with them but on many recordings it is not really necessary as the OBs do pretty well down to the 40Hz range.

I have a pair of original JBL 075 Ring radiator bullet tweeters that are sitting idle so when I have time and money I would like to use them as part of a truly high efficiency system (shooting for 97-100dB/W/m). I lean toward one or two 15" pro woofers up to 500-700Hz,  a 5" to 8" midrange or full range up to about 6kHz, and the JBLs above that. With something like that I could experiment with lower powered amps such as class A PP 6EM7s or even SE.

But before that I need to build a proper preamp and phono pre (I have designs on the drawing board). I am currently using a 70s vintage Realistic 4 channel mic mixer with built in phono for the preamp. Not exactly high end but it sounds much better than one would expect no doubt due to the rather simple discrete circuitry.

Below are pics of the amp (rather industrial looking as I originally intended to mount it in a console) and one of the speakers with the black grill cloth removed. MA driver is recessed which helps align the voice coils and the felt on the baffle seem to keep resulting difraction decently under control.


(https://www.audiocircle.com/image.php?id=197276)


(https://www.audiocircle.com/image.php?id=197277)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 5 Aug 2019, 07:01 am
Nice amp :thumb:
Seems these external chokes will run cool.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: opnly bafld on 5 Aug 2019, 11:52 am
A friend at work who's experience in audio is primarily in the megawatt car stereo arena can not even fathom single digit power output (I estimate mine is around 8wpc max).


You need 400 watts; "I guess a little education is in order, it's not all how loud one wants to listen, it's the dynamics you need to preserve."  :wink:   :green:  :duh:  :scratch:  :roll:  :lol:

Nice kit.  8)




Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: mashaffer on 5 Aug 2019, 03:18 pm
Thanks Fullrangeman. Yes the chokes run cool but I cut it a little close on the PT so it runs pretty hot but still probably OK.

Hi Opnly Bafld. That sure was an amazing exchange. :D
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 12:26 am
I too love the low wattage SET amp sound. In 2013 I built "THE BUGLE 45" amp. I am using homemade open back speaker enclosures with 15 inch woofer with 101.6 sensitivity, crossover at 4KC to a midrange-tweeter combo. I run a turntable with a high end cartridge thru a totally restored good 52 year old preamp to the 45 SET amp. I have set the 45 tubes to run at 1 1/2 watts not 2 watts. The back of the speaker enclosures are aprox 4 inches from a the wall. The audio sound is outstanding. Good soundstage, fidelity, clarity. good natural bass, fantastic smooth midrange and highs that reproduce bells as if they are in my room. I have been fooling around with sound systems since I was a teenager. I am now 77 years old with yet very good hearing. I am enjoying old technology in a whole new light.

Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Bemopti123 on 15 Nov 2019, 02:58 am
I too love the low wattage SET amp sound. In 2013 I built "THE BUGLE 45" amp. I am using homemade open back speaker enclosures with 15 inch woofer with 101.6 sensitivity, crossover at 4KC to a midrange-tweeter combo. I run a turntable with a high end cartridge thru a totally restored good 52 year old preamp to the 45 SET amp. I have set the 45 tubes to run at 1 1/2 watts not 2 watts. The back of the speaker enclosures are aprox 4 inches from a the wall. The audio sound is outstanding. Good soundstage, fidelity, clarity. good natural bass, fantastic smooth midrange and highs that reproduce bells as if they are in my room. I have been fooling around with sound systems since I was a teenager. I am now 77 years old with yet very good hearing. I am enjoying old technology in a whole new light.

Chuck

It would be great to see some pictures of different parts of this system.  Share with all of us audiophools some of these goodies.   :D
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 05:46 am
I built the amps in mono block design so that the left and right channels would not have any crossover problems. I will send pictures of the mono block amps but the input audio coupler capacitor has been changed to a higher end audio capacitor. I also upgraded the output transformer since these pictures were taken
(https://www.audiocircle.com/image.php?id=200884)

(https://www.audiocircle.com/image.php?id=200885)

(https://www.audiocircle.com/image.php?id=200886)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 15 Nov 2019, 07:23 am
Hi Chuck ~

What is the 15" bass driver you are using that has 101.6 sensitivity? And what is your midrange-tweeter combo?

Thanks ~ Richard
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 15 Nov 2019, 07:28 am
https://www.eminence.com/pdf/Delta_Pro_15A.pdf
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 05:02 pm
Richard, the 15 inch driver is an "Eminence Delta Pro 15" It has several things working for it. The accordion framework that attaches the speaker cone is not paper but is a special treated cloth that gives excellent moving ability to the cone. It does take a breaking in period. The 15 inch driver has an 80 ounce (5lb) magnet. It does not take much current to motivate this speaker. The midrange-tweeter combo is a "JBL-GTO 939" It does an excellent job. Musicians convinced me that the 15 inch driver  does very well at reproducing both bass and midrange. This 15 inch driver is good from 40 HZ to 4200HZ, thus my crossover network is set at 4000 HZ.
see more attached pictures.
Chuck
(https://www.audiocircle.com/image.php?id=200901)

(https://www.audiocircle.com/image.php?id=200902)

(https://www.audiocircle.com/image.php?id=200903)

(https://www.audiocircle.com/image.php?id=200905)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 06:05 pm
Richard, I forgot to put the "A" after" Eminence Delta Pro 15 A" You can verify the Specs on their web site as was mentioned on a previous post near mine.
Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 06:29 pm
Important point for all on these SET tube amps. They should be given a warm up time without high voltage B+. Why? If one has a very low resistance rectifier tube like a 5AR4 or a solid state rectifier allowing B+ very quickly it causes cathode stripping of electrons of the tubes before the tubes are in control. On my amps I have put a switch between the center tap of the high voltage winding to ground. Given a period of time for the tubes to warm up, then I close that switch to turn on the B+. You will save a lot of life of your tubes.
See another picture of the front of one of my mono block amps. You will see two switches, the big one is AC power on and off, the small micro switch is the on and off of the B+.
To shut down your amps turn off the B+ first then your AC power. See pix.

Chuck
(https://www.audiocircle.com/image.php?id=200908)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 07:53 pm
My thoughts on Gordon Rankin's Bugle 45 Amp. Very crucial to the workings of this amp besides the "sweet 45" tubes is the 9 pin 6072A tube. The commercial equal is the 12AY7 tube.  I found that the 12AY7 tube does not give the response of the 6072A tube. The 6072A tube is military tube was designed for the WWII military computers!! They are very high quality, designed to be very low in microphonics and high quality reproduction. Many use the GE black plates 6072A tube. I used them also for a time and was pleased with them. A few years ago I was fortunate enough to come across a few RCA long plates version of the 6072A tube. They were considered an extinct tube. The GE 6072A tube's plates are 14mm long. The RCA 6072A(also military) plates are 17mm long. I went back and forth exchanging the GE and RCA tubes and do find the RCA is a little more open and a little better in fidelity. The problem being we will probably never find these RCA long plates again.
If you desire to find out how this 6072 operates in the circuitry of the 45 Bugle amp I have a document on SRPP tube amplification document explaining its operation. It is this type of operation that gives the BUGLE 45 its unique sound.  Give me your e-mail address and I will send it to you.
Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: sonicboom on 15 Nov 2019, 10:32 pm
Important point for all on these SET tube amps. They should be given a warm up time without high voltage B+.

This is the widely accepted "fact" regarding stand-by switches, but it's wrong. Please read Blencowe's article on this topic. You're probably doing more harm than good.

http://valvewizard.co.uk/standby.html
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 11:21 pm
Richard, here is what I have gleaned from investigating tube amplification and solid state amplification. Simple triode tubes have a cathode coated with a substance that will release free electrons when the cathode is heated. The a plate with a positive charge that will draw those electrons. a grid that will control the flow of those electrons. when working if a sine wave input to the grid forms a flow of electrons to the plate matching the input sine wave but now with much more energy due to the high voltage. Thus voltage amplification. That is converted back to a high current flow thru an output xfmr. The sine wave is in tact matching the input. Hearing specialists and sound engineers have found that this type of tube amplification tends to exemplify the even harmonics of the fundamental frequency which are accepted well by our ear to brain function thus sounding louder than the db meters indicate.

In solid state devices are solid materials with positive to negative junctions. When a sine wave is entered the solid state material has to give up electrons thus becoming a positive charge or give up protons thus becoming a negative charge. What happens then is positive and negative current flow occurs in two directions. One is called electron flow the other called hole flow or positive flow. This constant interchange causes two sine waves of the original to flow in opposite directions. not only can this cause distortion but causes an emphasis on odd harmonics of the original frequency. This has been found to be irritating to the ear to brain interpretation, thus our brain tends to shut down the level. The musicians have indicated that their solid state amps sound like someone threw a blanket over them. This started a hard long investigation of sound reproduction be sound engineers, electronic engineers, ear specialists to find out the difference. This has led to our great SET low poured tube amps.

I use only vinyl because I have printouts of oscilloscope graphs showing all of the original sine wave missing due to the sampling rate of the digital sampling. I do realize that there is a great difference in the way different sound engineers and recording engineers do their vinyl recordings. Some over emphasize the highs which are very irritating. Some over emphasize the lows and out comes boom, boom, which is also very irritating. With my preamp I can get some control on this  with my tone controls.
With a passive preamp how do you deal with this?

My preamp is an EICO ST84. It uses 12AX7's thru out except for the rectifier. It was a kit when In bought it in 1967. It was a steal at that time because kit building had gone out of interest. I went thru it last year. Most of the carbon resisters were out of specs. replaced the resister, caps and tubes. The EICO ST84 is a highly sought after preamp now. I saw three of them sell on EBAY for over $900.00 last year.

Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 15 Nov 2019, 11:28 pm
sonicboom, thanks for your input. That is why I like this interchange of knowledge. We older ones have believed this standby switch thing for a long time.

Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: belle harbor on 16 Nov 2019, 12:24 pm
Having serviced thousands of pieces of audio gear, tube radios, and TVs over the past 60 years I can tell you that standby switching is totally unnecessary.  If you really want tubes to last you need to ensure that filament voltage remains within 5% of rating over all line voltage conditions.  Putting 7+ volts on a 6.3 volt tube will absolutely shorten its life.  Proper ventilation is also very critical.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 16 Nov 2019, 05:08 pm
Having serviced thousands of pieces of audio gear, tube radios, and TVs over the past 60 years I can tell you that standby switching is totally unnecessary.
This careless and neglect attitude to other people equipment is very common in North America even today, including famous hi-end manufacturers, its a general rule.

These past weeks there was a topic at DIY Audio where various members came to conclusion that soft start ramp voltage and a proper HV delay sequence are need to tube amps if one want his tubes lasts longer than the usual 2000 hours, and we know some tubes can be quite expensive.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 16 Nov 2019, 06:36 pm
I also have a long background in working on tube amps and tube radios. It is not just the filament voltage that we are talking about. If we connect an old antique tube radio to high line voltages of today we are asking for trouble. My line voltage runs between 122 and 124 volts AC. When an old tube radio is connected to that,
 not only will the filament voltage be too high, think of the high voltage winding. If the radio had been run on 110 volts before with 250 or 300 VDC on the plates of some tubes, think what it would be with a line voltage of 122 to 124 AC.
Note a picture of an easy fix for these old antique radios which I found on Anglefire website
Chuck

(https://www.audiocircle.com/image.php?id=200940)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 17 Nov 2019, 02:40 am
Richard, I seemed to have overlooked your statement about the on line equalizer you use. So, now I understand how you cope with too much high or too much low. At my age I am not very good at using internet music.

 When I was young I had lots of records, but all were lost. Around 15 years ago I was able to buy records for 10 cents each at thrift stores. I would just throw away the bad ones. It is surprising how many very good records I have. The top of the line recording company was "COMMAND" records. They even got into cutting records from 35 MM film that performances were recorded on. It is interesting how "real sounding" good vinyl is. Most new vinyl I have tried were recorded off of CD's and very poor audio.

Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 17 Nov 2019, 04:05 am
Most new vinyl I have tried were recorded off of CD's and very poor audio.
The mastering for CDs and vinyl are very diferent.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 17 Nov 2019, 05:24 am
My last post tonight.
 It gives me a great deal of pleasure to see so many good informative posts.
What really is amazing to me is to see how so many of you have so beautifully merged or blended the very new sound technology with the old tube sound technology and having it excite you when it turns out so good for you. I really did not think I would ever see this happen.
Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: belle harbor on 17 Nov 2019, 12:02 pm
Chuck, B+ is not usually an issue unless the design-maximum tube ratings are exceeded.  In terms of vintage tube audio gear, radios, and televisions most were designed to operate at a line voltage of 105-125.  At the higher voltages it is usually the filaments which are going to take the hit.  An elegant solution for those who are concerned is a variac. 

Gustavo, I’m not aware of a careless attitude when it comes to tube equipment.  My service shop could not have remained in business if premature tube failure was an issue.  In my own amp designs 25000+ hours on output tubes is typical while the small signal tubes last “forever.”
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 17 Nov 2019, 06:57 pm
Gustavo, I’m not aware of a careless attitude when it comes to tube equipment.  My service shop could not have remained in business if premature tube failure was an issue.  In my own amp designs 25000+ hours on output tubes is typical while the small signal tubes last “forever.”
Great, I will send you my tubes for you bless them.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 25 Dec 2019, 11:43 pm
Hi Chuck ~ Just today I dived back into this thread. Forgive me for not responding sooner.

I wonder what the actual sound difference is between the "Eminence Delta Pro 15A" and the less stellar version I am using, the 'regular' 15" Eminence 15A". Perhaps it is faster suggesting more detail and less tonal overhang (less holding onto notes), therefore more resolution and precision of musical textures?

I am awaiting a new set of ancillary tubes for my 45 amp. The 80 rectifier tube keeps arcing and it has pulled the EML Mesh Plate 45 tubes to a lower output efficiency which translates to less perceived detail. I ordered the Neotron 80 from Jac in Germany along with a pair of mushroom 717A's. I am curious to see what effect a fresh 80 rectifier has on the sound.

We who use low watt tube gear must certainly have a fetishistic relationship with the tubes, the delicate glass, the glow, the need for extreme care in handling them, experimenting with different versions and so on. I think it is similar with vinyl records. The 'feel' of the large record as it taken from its secret residence, the way the grooves reflect the light with certain lighting, the needle in delicate contact with the surface, the rising and falling of the tone arm as it traverses the pathways of the concentric grooves.

No doubt the 'analogue' sound of LP's is there; by which I mean that 'something' is there, some dimension of the sound. But what exactly is that? I ask this respectfully out of sheer curiosity. Since I began streaming with Tidal playing through Audirvana (by itself Tidal is a little 'raw' sounding), using my low watt 45 amplifier to drive the mid-to-upper frequencies on my Lowther PM5A Ticonal speakers on OB's, I feel that the sound is as close to 'live' as is possible through mechanical reproduction. Not perfect, not really 'live', but close. I remember listening to LP's, a rich, viscous texture, palpable.

Since I do not want to use my Yammie while I await for a fresh 80 rectifier tube (who knows, if the failing one I am now using actually goes, it could take the EML 45 tubes with it) I have inserted my TBI Millenia 'digital' class BD amp instead to drive the Lowthers. The sound is so 3-dimensional, rich and nicely resolved that I am quite shocked at its performance. I was using it previously for bass duties with my 15" Eminence drivers. Instead I am using a modified Heathkit (from the golden age of audio) integrated amplifier with tone controls for the bass. So tubes are still in the sound.

But, and this is important, no matter what combination I use of amplifiers and passive preamplifiers, care must be taken to dial-in everything for optimal performance. Perhaps for people with big-bucks, a plug and play system can work for them. But considering that at least some of ones system is DIY means that a dialing-in of everything is necessary.

Merry Christmas, dear Audio Circle members. Everything good and light-filled for the New Year. It may be a bumpy-ride.

With Friendship ~ Richard
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 28 Dec 2019, 08:13 pm
The 'new' (NOS) Neotron rectifier tube arrived yesterday along with an NOS pair of 'mushroom' 717A's. The difference is astounding! And just as I surmised, it was the failing 'original' 80 rectifier tube that was dragging the 45 tubes down.

Since the Yamamoto A08S has a built-in meter that shows the strength of the 45 tubes, it is clear that they are back to their original 'new' strength. More than that, the Yammie sounds better than when it was new. So if your SET tube amplifier seems to have lost its 'magic', that effervescent sparkle and delicious transparency, it could be the rectifier tube not the actual output/power tubes that need replacement.

This is nice gift for the New Year. The magic is back.

With Warmest Friendship ~ Richard
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 29 Dec 2019, 12:04 am
Hi Richard, the rectifiers lasts how many hours in your Yamamoto ?
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 29 Dec 2019, 12:21 am
Hi FullRangeMan ~ My sense of 'time' has all but dissolved with age. However I think that I received my Yamamoto A08S about 5 years ago, but it could be a year or so more.

It has been in continuous use since then. Jac of JacMusic thinks that the Rectifier 80 tube is good for 5,000 hours. It began to show signs of failure about 3 to 4 weeks ago. The 45 tube strength dropped, the 80 sparked on 'turn-on' and there was a crackling sound. I am happy to say that the Yammie sounds rather fabulous with the new Neotron 80 inserted.

Warmest Regards ~ Richard
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: FullRangeMan on 29 Dec 2019, 12:54 am
Thanks Richard :thumb:
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Chuck Harris on 6 Feb 2020, 06:08 am
Richard, I too apologize for not getting back to you sooner. Yes the Delta Pro 15 is very responsive, excellent base and midrange in all sorts of music. I crossover at 4KH to the midrange and tweeter speaker.  This is interesting as my amp is the Bugle 45 designed by Gordon Rankin using the 45's at only 2 watts output per channel, yet I can drive the dickens out of the Delta Pro 15. My overall sound is very real, sound stage presence which is exciting to hear.

I us a 5V4 for my rectifier tube. It is much like the newer 5AR4 but much cheaper. I compared using the 5Y3 and the 5V4. The 5Y3 has a much higher plate resistance than the 5V4, thus a lower plate voltage on the 45's using the 5Y3, plus also a slower capacitance charge on the power supply large caps which changes the bass response. I prefer the low resistance 5V4 fast recovery.

The driver tube to the 45 is a 6072A long plate RCA. I have not found anything that sounds better than that, although a 6189 Sylvania long plate is close. The 6189 has much lower gain but gives me more control on the preamp.
Chuck
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: rollo on 16 Sep 2020, 06:27 pm
   Guys using a 6AX5 for rectifier, a Raytheon driving GE 45s. Want to try other 45s just not sure which ones. What compares or betters EML ?

charles
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: roscoe65 on 16 Sep 2020, 10:37 pm
   Guys using a 6AX5 for rectifier, a Raytheon driving GE 45s. Want to try other 45s just not sure which ones. What compares or betters EML ?

charles

6AX5 rectifier - not many options there.  I guessing an Alan Eaton amp.  You didn’t mention what tubes were driving the 45s, so I will guess 6SN7.  A lot of people like NOS or good vintage globe 45s.  Konrad and Arcturus are a couple of good, if pricy choices.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: jmdavidson87 on 18 Sep 2020, 05:26 am
I am using an Art Audio PX-25 with my Klipsch La Scalas (104dB efficient). The power tubes are NOS Osram PX-25’s, which produce 6 watts/ch.  It’s quite a magical setup.

(https://www.audiocircle.com/image.php?id=214750)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Les Lammers on 18 Sep 2020, 08:05 am
It's puzzling to me that in almost 2018, there is so few choices in solid, low-cost streamers that offer coax spdif output.
Like most audiophiles, I already own high end DAC's and would like a good streamer that has good coax spdif out.  If no coax, would take regular toslink preferably over mini toslink, and analogue outputs are not needed. 

Looking around, I might just have to pick up Chromecast Audio unless there are better options.. :scratch:

Streaming/computer audio drove me nuts. Too much jargon etc. I bought an Arcam rPlay, now discontinued, when Parts Connexion, had them for $299. I stream Tidal to a MHDT Labs Orchid DAC.

I never fully understood the Raspberry Pi thing but I get it now. I am going to order this, https://www.allo.com/sparky/digione-signature-player.html, with the Shanti power supply. It's future proofed, as much as digital can be, because you can run different software.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Les Lammers on 18 Sep 2020, 08:26 am
I have a few flea amps and really enjoy them.  I bet there are many of us lurking with sweet and simple tube amps (maybe not as nice as Richard's  :green:).

BTW, if you want to try a cool speaker that's cheap and easy to make, grab a set of Saba console greencone drivers (woofer and tweeters) from the 1950's. I have mine mounted in simple floorstanding, open-backed plywood boxes using one cap for the tweeter crossover.  They are efficient and sound great with sane decibels.  I got mine from a German guy on ebay and they are in excellent condition.  I suppose it makes perfect sense they get along well with low power tube amps.  :D

I have three Chromecast audio units streaming Tidal hifi.  Again... another good sounding, cheap thrill.  I bought some decent 3.5mm to RCA plug ICs on Amazon and it's fun to sit back and dream of different music to play.  It's a nice way to discover/investigate music before investing in vinyl or CDs if you're like me and addicted to tangible formats.

Yes, the Isophone, Telefunken, Grundig speakers have Alnico magnets and sound wonderful with flea watt amps. I just got a pair of Isophon-ph2132 Coaxes and will have them in a quasi open baffle soon. They are 97db with a 5.5uf cap for the crossover. I will drive them with a 45/2A3 Inspire amp from Dennis Had.

(https://www.audiocircle.com/image.php?id=214752)

(https://www.audiocircle.com/image.php?id=214753)

(https://www.audiocircle.com/image.php?id=214751)
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: Les Lammers on 18 Sep 2020, 08:43 am
   Guys using a 6AX5 for rectifier, a Raytheon driving GE 45s. Want to try other 45s just not sure which ones. What compares or betters EML ?

charles

Personally, *I* like the EML solid plates and prefer them to the mesh version. I have the TJ Full Music 45's they are OK but the EML is in another dimension.
Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: -Richard- on 19 Sep 2020, 11:03 pm
The question of which 45 tubes sound the 'best' may be similar to asking which cables sound the best.

I am only suggesting that the answer may depend on the rest of one's gear and what 'sound' gives you the most pleasure. For example, which EML 45 tubes sound best, the Mesh Plate compared to the Solid Plate, depends on how you would want to bias the sound of your 45 amplifier. The Solid Plate is strong and clear and you can expect something similar to a highly resolving Solid-State-like rendering of the leading edges of transients, especially sharply struck sounds, while the Mesh Plate has more tonal complexity and perhaps a little more depth.

I once purchased a pair of RCA 45 tubes made in 1949 or 1950, sorry I no longer remember which date, from a chap in Florida who said they were found in a garage where they had been sitting among chickens for 55 years! After I brushed off the chicken poop from the original boxes and set them into the 45 amp I was using at that time they rendered a sonic performance that was supremely magical.

I no longer have that set-up, having changed things around quite a bit since then, including, and this is just as important, my listening habits and biases. We could well ask, if the admittedly retro technology of LP's with all of the accompanying ancillary gear like sophisticated styluses and turn-tables, have made such a dramatic comeback in the last 10 years, why have not tube manufacturers come up with 'flavors' of tubes, such as the legendary 45's, that could satisfy the sophisticated tastes of tube-lovers?

Which EML 45's, Mesh Plate or Solid Plate, work best in my current system actually depends on what music I am playing. However, right now I own only the EML Mesh Plate and a few coke-bottle type 45's from the golden age of audio.

I used to see bushels of 45 tubes for sale around 10 years ago, now there presence is becoming unfortunately quite thin.

Best of luck to you. With Warmest Friendship ~ -Richard-




Title: Re: My Low Watt SET amp & High Sensitivity Speaker Journey ~
Post by: isaacc7 on 25 Sep 2020, 01:28 am
Streaming/computer audio drove me nuts. Too much jargon etc. I bought an Arcam rPlay, now discontinued, when Parts Connexion, had them for $299. I stream Tidal to a MHDT Labs Orchid DAC.

I never fully understood the Raspberry Pi thing but I get it now. I am going to order this, https://www.allo.com/sparky/digione-signature-player.html, with the Shanti power supply. It's future proofed, as much as digital can be, because you can run different software.

Pretty sure the Sparky based systems have been deprecated/discontinued. The new thing is their USBridge Signature. You can use the USB output or you can add the digione board to the USBridge. Just make sure to get the right case and two power supplies.