SET amp or push-pull for SD speakers voicing

0 Members and 1 Guest are viewing this topic. Read 11948 times.

Mariusz

SET amp or push-pull for SD speakers voicing
« on: 12 Oct 2008, 10:47 pm »
I am in the middle of two projects.
Sachiko - double back loaded horn speakers
and these:



I have two amps that can be used to voice these speakers:
Melody M300b SET monos 8wpc
and Consonance Cyber 800 monos 78wpc push-pull.

The Sachiko is of course a SD design , that will use custom Fostex Fe206eF drivers (by Dave).
The other design will most likely use the similar drivers as well as super tweeter.  :drool:


Which amp in your opinion is a better candidate to be use for voicing these speakers?  :scratch:

Thanks  :thumb:

SET Man

Re: SET amp or push-pull for SD speakers voicing
« Reply #1 on: 13 Oct 2008, 02:22 am »
Hey!

   SET amp of course!  aa Well, what else do you expect from me?  :lol:
 
   I use the 6" FE167E with 18w SET monoblocks and it play more than loud enough in my room. Although you will get better weight and control on the bottom end. But that depend on the quality of the amp also.

  And there is something special about Single Driver and SET amp combo. :wink:

Take care,
Buddy :thumb:

Mariusz

Re: SET amp or push-pull for SD speakers voicing
« Reply #2 on: 13 Oct 2008, 03:22 am »
Hey Buddy,
I kind of expected that your preferences will side with the SET amp.
As to quality of both amps, well:
Melody M300b monos (I can not say with certainty. Will have them home soon.) are said to be very quiet, which is a good thing. If their qualities resemble the I2A3 integrated (heard that one on few occasions), I will be very pleased.
My concern is the best way to voice my speakers though. Warmish character of Melody amps with only 8wpc or very dynamic and more on the neutral side Cybers 800? My preferences are of second importance. Since I have few friends that are interested in these and I will build quite a few pairs.......my question is this:

Since I have no influence on their choice of the amplification, do I voice them towards my own preferences and taste or compromise.....and use both amps in the process. I am unable to predict the sound and results they will accomplish with the use of amp X or Y.  I also can not spend endless time tweaking them individually to taste.

Will the 8wpc be able to deliver enough headroom to preserve the dynamics and low frequency rendition without sacrifices ?

Thanks Buddy

Mariusz







slbender

  • Jr. Member
  • Posts: 128
    • The Bender Rebuild Vintage Amplifier Pages
Re: SET amp or push-pull for SD speakers voicing
« Reply #3 on: 13 Oct 2008, 08:56 am »
Hey Buddy,

My latest SET Amp (18 months in the making) had its initial listening test last weekend at the Audio Syndrome / Gotham Audio Annual BBQ, on the South Shore of Long Island in Seaford.  While the amp is almost finished, I decided to bring it along, despite not having run a full set of tests on it.  My initial tests were done barely five minutes before I was picked up to go to the BBQ. Initial tests showed output of 18vp-p across 7.5 ohms which is around 5 Watts per channel; -3dB points were around 24-27 Hz. and well above 20kHz. on the high end.  Gain was just over 1.0 volt required for full output, and Signal to Noise was on the order of 64dB, but I need to get a quieter fan, or run this one slower than it is now.  So while the Amp still needs to be tweaked and a few things checked, and a full set of distortion tests to be done this week, and perhaps it needs to be optimized and maybe bypassed a little more, I figured it was ready for prime-time listening.

At the meeting, we first listened for about an hour to the original (vintage) system which consisted of: a Playstation1 as the CD Player, modified Dynaco PAS w/o tone controls, a moded Dynaco Stereo 70, and a pair of Dynaco A-25 speakers, and a smallish AR Subwoofer.  Then after eating and deserts, we again listened to the original system for a half hour, then someone had a new Digitally Controlled Preamp prototype (using fast IC's and an external power supply) which was hooked up in place of the PAS. Listening again for about a half hour, the system was both pleasant and detailed.

Finally after about 7 PM, my little SET Amp was hooked up, and the Digital Preamp remained connected.  All of a sudden there were Oh's! and Aaahh's! and smiles all around. And now, nobody wanted to leave, some three hours later, our host finally kicked everybody out as it approached 10 PM.  Of the dozen or so CD's played in the last part, only one didn't sound good, its dynamics were constantly clipping my flea-powered SET.  The rest of the CD's sounded great. The soundstaging, musicality, clarity, and detail were better than the typical SET or other amps.  This amp was designed and intended to be the equivalent of a 2A3 Triode at around 3.5 - 4 Watts per channel and it nicely meets that criteria.  The stereo amp is small and rather light-weight at only about 12 lbs. without its carry around suitcase.  So I'll probably bring it to several of the Raves and Meetings I go to in the next year or so.  I'm already building the next two higher power versions of this SET amp, but they won't be ready for quite a while yet.


-Steven L. Bender


Hey!

   SET amp of course!  aa Well, what else do you expect from me?  :lol:
 
   I use the 6" FE167E with 18w SET monoblocks and it play more than loud enough in my room. Although you will get better weight and control on the bottom end. But that depend on the quality of the amp also.

  And there is something special about Single Driver and SET amp combo. :wink:

Take care,
Buddy :thumb:

JimJ

  • Full Member
  • Posts: 780
  • Ut Prosim
Re: SET amp or push-pull for SD speakers voicing
« Reply #4 on: 16 Oct 2008, 01:24 am »
I'd go for the SET, in my opinion :)

Save the PP amps for speakers that need a little more grunt.

Just curious, what's the turntable in your avatar? Looks cool  :drool:

Mariusz

Re: SET amp or push-pull for SD speakers voicing
« Reply #5 on: 16 Oct 2008, 03:00 am »
Hey Buddy,

My latest SET Amp (18 months in the making) had its initial listening test last weekend at the Audio Syndrome / Gotham Audio Annual BBQ, on the South Shore of Long Island in Seaford.  While the amp is almost finished, I decided to bring it along, despite not having run a full set of tests on it.  My initial tests were done barely five minutes before I was picked up to go to the BBQ. Initial tests showed output of 18vp-p across 7.5 ohms which is around 5 Watts per channel; -3dB points were around 24-27 Hz. and well above 20kHz. on the high end.  Gain was just over 1.0 volt required for full output, and Signal to Noise was on the order of 64dB, but I need to get a quieter fan, or run this one slower than it is now.  So while the Amp still needs to be tweaked and a few things checked, and a full set of distortion tests to be done this week, and perhaps it needs to be optimized and maybe bypassed a little more, I figured it was ready for prime-time listening.

At the meeting, we first listened for about an hour to the original (vintage) system which consisted of: a Playstation1 as the CD Player, modified Dynaco PAS w/o tone controls, a moded Dynaco Stereo 70, and a pair of Dynaco A-25 speakers, and a smallish AR Subwoofer.  Then after eating and deserts, we again listened to the original system for a half hour, then someone had a new Digitally Controlled Preamp prototype (using fast IC's and an external power supply) which was hooked up in place of the PAS. Listening again for about a half hour, the system was both pleasant and detailed.

Finally after about 7 PM, my little SET Amp was hooked up, and the Digital Preamp remained connected.  All of a sudden there were Oh's! and Aaahh's! and smiles all around. And now, nobody wanted to leave, some three hours later, our host finally kicked everybody out as it approached 10 PM.  Of the dozen or so CD's played in the last part, only one didn't sound good, its dynamics were constantly clipping my flea-powered SET.  The rest of the CD's sounded great. The soundstaging, musicality, clarity, and detail were better than the typical SET or other amps.  This amp was designed and intended to be the equivalent of a 2A3 Triode at around 3.5 - 4 Watts per channel and it nicely meets that criteria.  The stereo amp is small and rather light-weight at only about 12 lbs. without its carry around suitcase.  So I'll probably bring it to several of the Raves and Meetings I go to in the next year or so.  I'm already building the next two higher power versions of this SET amp, but they won't be ready for quite a while yet.


-Steven L. Bender


Hey!

   SET amp of course!  aa Well, what else do you expect from me?  :lol:
 
   I use the 6" FE167E with 18w SET monoblocks and it play more than loud enough in my room. Although you will get better weight and control on the bottom end. But that depend on the quality of the amp also.

  And there is something special about Single Driver and SET amp combo. :wink:

Take care,
Buddy :thumb:

Hope to hear it in the future Steven.

I'd go for the SET, in my opinion :)

Save the PP amps for speakers that need a little more grunt.

Just curious, what's the turntable in your avatar? Looks cool  :drool:

Thanks, I think it is the right thing to do.
One of the guys did if fact purchase the Set amp just for these speakers (it was not easy to convince him though). He got a nice deal on Consonance Cyber 211 monos (I've heard those......nice amps).
As to the TT in my avatar,
it is DIY table named "Red Devil". You can not see it (old pic) but it has a dedicated stand (same shape), acrylic arm-board and Moarch UP4 uni-pivot arm/Denon103R cart. It weights well over a 100 pounds. Sandwiched 11 layers of Baltic birch and MDF. Motor is not in contact with actual plinth to reduce vibration.
Here are some pics from the build process:






















JimJ

  • Full Member
  • Posts: 780
  • Ut Prosim
Re: SET amp or push-pull for SD speakers voicing
« Reply #6 on: 17 Oct 2008, 05:50 am »
Very nice work :)

Mariusz

Re: SET amp or push-pull for SD speakers voicing
« Reply #7 on: 18 Oct 2008, 03:26 am »
Very nice work :)


Hey.....thanks.  :thumb:
Do what I can......within budget and skills.
It was my first (designed) turntable.....you know what they say about the first???  aa

Actually this one was my first modification.  :lol: 
 I am sure you know what TT was used.  :idea:










Scottmoose

  • Jr. Member
  • Posts: 107
Re: SET amp or push-pull for SD speakers voicing
« Reply #8 on: 19 Oct 2008, 09:35 am »
Nice. :^) I really should get on with re-housing my Lenco GL78 idler drive. I've got this worrying urge to use marble or soap-stone though. I'd love to use slate, but it's way beyond my budget.

Back to the original subject -depends on the amp. It's a bit over-simplistic to simply draw a line SET - PP. I've heard examples of the latter I love & examples of the former that were downright terrible, and visa versa. FWIW, I'd likely be inclined toward the former, which is what I had in mind when I designed Sachiko anyway (spoilt because three / four of my friends are arguably the finest valve amp designers in the UK).

floobydust

  • Jr. Member
  • Posts: 183
Re: SET amp or push-pull for SD speakers voicing
« Reply #9 on: 19 Oct 2008, 10:43 am »
 Agreed, for good single drivers a well-done SET can be simply superb. I'm still heavily engaged with the 45 triode, if you can survive the 2-watts of output. I have one of the best collection of 45 triodes around... totaling more than 25 matched pairs, all NOS and of multiple brands. Over the years I have concluded that one particular internal construction wins hands down over all the others. Regardless of popular opinion, RCAs are not on my list, I have numerous matched pairs of both globe and ST glass and I don't like any of them. They are also the worst on hum balance by a wide margin compared to most others.

 Regards, KM

Scottmoose

  • Jr. Member
  • Posts: 107
Re: SET amp or push-pull for SD speakers voicing
« Reply #10 on: 19 Oct 2008, 03:49 pm »
You & my mate Steve would get on. He's got what appears to be the world supply of 1930s vintage PX4s. ;^)

JimJ

  • Full Member
  • Posts: 780
  • Ut Prosim
Re: SET amp or push-pull for SD speakers voicing
« Reply #11 on: 20 Oct 2008, 05:47 pm »
Agreed, for good single drivers a well-done SET can be simply superb. I'm still heavily engaged with the 45 triode, if you can survive the 2-watts of output. I have one of the best collection of 45 triodes around... totaling more than 25 matched pairs, all NOS and of multiple brands. Over the years I have concluded that one particular internal construction wins hands down over all the others. Regardless of popular opinion, RCAs are not on my list, I have numerous matched pairs of both globe and ST glass and I don't like any of them. They are also the worst on hum balance by a wide margin compared to most others.

 Regards, KM


I first heard a pair of 45 monoblocks earlier this year, I know exactly what you mean :) They were midrange amplifiers in a 3-way horn setup...just gorgeous sounding.

I need to get out of this apartment before I go that route, though, the speakers I'd need to satisfy my output requirements with that kind of power would be hell getting up to the 3rd floor :D

ghpicard

Re: SET amp or push-pull for SD speakers voicing
« Reply #12 on: 23 Oct 2008, 10:54 pm »
I have one of the best collection of 45 triodes around... totaling more than 25 matched pairs, all NOS and of multiple brands.

Was this cruelty to your fellows really necessary ???

 :D :D :D :D :D :D

I really love '45s sound, and you are right, it's difficult to survive their 2Watt (peak) power in SE. But that's what EL84PPs are for :)
I'm currently planning to build an OTL to see if I like it too, but the SET45 is and will keep being my primary system for a loooong time, I hope.

Mariusz

Re: SET amp or push-pull for SD speakers voicing
« Reply #13 on: 24 Oct 2008, 02:22 am »
Hey guys and thanks for your feedback.
I am leaning towards the SE for its middle range qualities.
Of course I will try both, however - voicing wise , I think others including myself would think that SD speakers ( especially these) would really sound right with SE amp(s).
As I have mentioned before, I have tried both (my PP and same brand SE) with similar designs (same drivers were used as the ones in my design).
PP sounded more dynamic IMO.
SE excelled in mids and surprisingly the bass wasn't locking.....not at all. Actually there was plenty of quality bass to satisfy most .....except the "thunder" freaks.
It was a close call though.
Could be becouse the amps were made by the same manufacturer (Consonance [211 SE and 800PP] Audio also known as Opera Audio in Asia).

Here is the prototype speaker and my Lenco which is awaiting a brand new shiny plinth.





and

Sachiko based SD with super tweeter on top.





Thanks
Mariusz


floobydust

  • Jr. Member
  • Posts: 183
Re: SET amp or push-pull for SD speakers voicing
« Reply #14 on: 24 Oct 2008, 07:15 am »
I have one of the best collection of 45 triodes around... totaling more than 25 matched pairs, all NOS and of multiple brands.

Was this cruelty to your fellows really necessary ???

 :D :D :D :D :D :D

I really love '45s sound, and you are right, it's difficult to survive their 2Watt (peak) power in SE. But that's what EL84PPs are for :)
I'm currently planning to build an OTL to see if I like it too, but the SET45 is and will keep being my primary system for a loooong time, I hope.

 Gee, that wasn't really cruel... my 45 amps deliver a solid 2.25 watts RMS. Look at the bright side, at least you'll know which 45 brands to avoid when you buy another pair. I prefer the older Sylvania internal construction in ST glass with the cut-side top micas, specifically with the dual spring wire supports (mica to glass envelope) and rivots on the support wires (see attached pic, sorry for the bad quality). All others fall a bit short of these IMHO.



 I also did a simple low-cost 45SET recently and put it out here for all to see, build, enjoy... (or not) complete with a schematic and BOM list. The first pair of monoblocks were dropped off to my Dad to play with... he's having a ball.

 Regards, KM

ghpicard

Re: SET amp or push-pull for SD speakers voicing
« Reply #15 on: 24 Oct 2008, 11:21 am »
I have one of the best collection of 45 triodes around... totaling more than 25 matched pairs, all NOS and of multiple brands.

Was this cruelty to your fellows really necessary ???

 :D :D :D :D :D :D

I really love '45s sound, and you are right, it's difficult to survive their 2Watt (peak) power in SE. But that's what EL84PPs are for :)
I'm currently planning to build an OTL to see if I like it too, but the SET45 is and will keep being my primary system for a loooong time, I hope.

 Gee, that wasn't really cruel... my 45 amps deliver a solid 2.25 watts RMS. Look at the bright side, at least you'll know which 45 brands to avoid when you buy another pair. I prefer the older Sylvania internal construction in ST glass with the cut-side top micas, specifically with the dual spring wire supports (mica to glass envelope) and rivots on the support wires (see attached pic, sorry for the bad quality). All others fall a bit short of these IMHO.



 I also did a simple low-cost 45SET recently and put it out here for all to see, build, enjoy... (or not) complete with a schematic and BOM list. The first pair of monoblocks were dropped off to my Dad to play with... he's having a ball.

 Regards, KM


I only own a (dis)pair... One's a Cunningham 245(IIRC) and the other one an RCA 45. Both ST shaped, both were my grandfather's.
I can't do A/B due to the fact that I never got enough time to build the other "channel" of the dual monoblock.
I have to make plans to get some replacements as their coatings are running out...

And you are running them hot, KM ! :)

Regards
   G

boead

Re: SET amp or push-pull for SD speakers voicing
« Reply #16 on: 24 Oct 2008, 11:36 am »
...had its initial listening test last weekend at the Audio Syndrome / Gotham Audio Annual BBQ, on the South Shore of Long Island in Seaford. 

I grew up in Seaford. I still have friends there.

SET. I've had a couple, still have them. A modified Decware (EL84's) and McAlister (6JM6). Pleanty of drive with the right speakers.

Oh and my Alons are very inefficient! Open Baffle, 3-way crossover at 86db and still my 16wpc McAlister rocks them! My 2wpc Decware can only just make them whisper. I also have a pair of ParkerAudio Model 95 sigs. (MTM's, ribbon tweeter, 95db, no crossover)

BTW: My Decware and Parkers are for sale, I think. I just moved and don't have anyplace to use them. The Decware amp was voiced (modified) by Eddie Vaughn of Vaughn Audio. (http://www.vaughnaudio.com/)

floobydust

  • Jr. Member
  • Posts: 183
Re: SET amp or push-pull for SD speakers voicing
« Reply #17 on: 24 Oct 2008, 12:07 pm »
 Hi G,

 Cunningham tubes were made by RCA essentially, I also have some early ones in ST glass with engraved bases with both RCA and Cunningham on them. I don't like DC filaments on the 45... should not have to if they're nice ones. As for running conditions, the tube manuals are pretty spot on. The later specifications showed the following:

Plate Dissipation = 10 watts
Plate Voltage = 300 volts
Cathode Current = 36ma

 I would regard cathode current as a bit more sacred here, as the cathode is basically the "heart" of the tube. Later ST glass is pretty rugged overall, at least "my favorite" ones are. In my designs, I tend to run around 34ma on cathode current and the cathode-to-plate voltage around 295 with a 5K load impedance. This calculates to 10 watts almost on the dot. Output power, with a good 45, should be a solid 2.25 watts, maybe a bit more with exceptional tubes.

 I also have a new manufacture pair of EML 45 solid-plate tubes... huge thick glass bottles and on the butt-ugly side (IMHO). They are built like the proverbial brick house and might outlive you. These really need to be run around 40ma of cathode current before they start to open up and sound decent. I also find them to be quite sensitive to mechanical vibration... lightly tap on the chassis and watch the scope, you get an eyeful of flutter. The only logical cause for this is long filament wires moving slightly from mechanical excitation, i.e., do NOT mount them in any orientation other than vertical. They don't have the same internal structure as a classic 45 and they don't really sound the same. As a result, I don't consider them as "drop-in replacements". You also need to push them to a good 12-13 watts on the plate too. On other flip side, you can bias them a bit hot and get over 3 watts out of one.

 As for replacements, there are still some good ones out there. Once I get back to US for a bit I plan on selling some of the pairs I have. Granted, not my preferred ones, but I do have many excellent pairs, just the wrong internal structure for me.

 Regards, KM

Docere

Re: SET amp or push-pull for SD speakers voicing
« Reply #18 on: 3 Nov 2008, 12:26 am »
Quote
These really need to be run around 40ma of cathode current before they start to open up and sound decent.

Thanks for sharing your experiences. That seems to differ to some other folks' opinions, in that the EML45 sounds a little more dynamic, yet somewhat unruly and stressed at higher points. Perhaps this could compensate for a particular amp voicing – after all, these observations are made within a certain context by an observer with specific preferences, wants (aware and unaware), etc. My concern at running the EMLs at that point is tube life; EMLs in general seem to have significantly improved reliability and longevity when run at low dissipation vis-à-vis common or higher points. However, as you say, the EML45's are appear hefty... tho, that does not necessarily translate to reliability. I'd be asking Jac for some guidance as well.

Again, thanks for taking the time to share your experiences.

Cheers

floobydust

  • Jr. Member
  • Posts: 183
Re: SET amp or push-pull for SD speakers voicing
« Reply #19 on: 3 Nov 2008, 07:15 am »
 Hi Docere,

 There are a many causes for premature failure of tubes... heat is one, pushing the cathode beyond it's capability is another and of course there are more. As for the EML45, I would look at heat and cathode in the context of the discussion here. From my humble view and long-term experience, heat will not be an issue with the EML45. The glass envelope is so large and the plate structure is so massive (both when compared to a standard ST-glass 45) that they don't get much beyond warm. Even after many hours of use, you can easily touch anywhere on the glass envelope and it doesn't get very hot, not so with an ST glass NOS 45... they can get pretty hot. The second area is the cathode emission. The EML45 has 4 long and robust filament wires. At 2.5VAC they don't really glow as brightly as the NOS ST versions... and they are quite a bit longer as well. When you tour the EML site and look at what their goals are, I don't see running them at 40ma as a problem either (original spec is 36ma). Just my $0.02.

 Regards, KM