[seikosha]

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.

[FullRangeMan]

I liked this Quicksilver Horn very big power transformer,
somewhat unusual today due cost saving.

[tybee]

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.

[Rocket_Ronny]

Hi Richard.

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


Rocket Ronny

[-Richard-]

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

[rollo]

Hi Richard yes, Rethms and pasta do seem to go together very well. Especially when accompanied with wine.Love yo have ya.

charles

[rollo]

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

[-Richard-]

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.

[bopnote]

WOW!

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

Thanks   

[Bumpy]

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

[-Richard-]

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-

[Tyson]

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. 

[mashaffer]

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.

[FullRangeMan]

Nice amp
Seems these external chokes will run cool.

[opnly bafld]

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."            

Nice kit. 

[mashaffer]

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.

[Chuck Harris]

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

[Bemopti123]

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.   

[Chuck Harris]

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

[-Richard-]

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