SETs vs old SS � Listening experiments

[DrWho]

One would think that the best spec amp would sound the best, but we know that isn't necessarily true.

Exactly how I feel [] Which is why as a young naive budding engineer I would like to see more effort put into trying to quantify the lack of correlation instead of sign it off as mystical - how cool would it be to have the best of all worlds of amplification? [H]

Mike, can you hook an RTA directly up to the amp outputs? Use it the way you would a scope, but not have to plot all the individual frequencies? The RTA would have to have a high input imepdance to do that. I want to measure the amp outs and not include the speaker system (including room gain, etc)

I'm not sure. But it is definetly something I've been meaning to try with my computer. Shawn (sfogg) says it's ok because the high impedance won't draw much current. This will give you the electrical sum of the amp-speaker interaction, but won't say much in terms of the actual acoustical output. If you'd like to look at your acoustical performance without the effects of the room and you have a computer nearby then you might consider looking into something like http://www.etfacoustic.com/

[Marvel]

One would think that the best spec amp would sound the best, but we know that isn't necessarily true.

Exactly how I feel [] Which is why as a young naive budding engineer I would like to see more effort put into trying to quantify the lack of correlation instead of sign it off as mystical - how cool would it be to have the best of all worlds of amplification? [H]

Mike, can you hook an RTA directly up to the amp outputs? Use it the way you would a scope, but not have to plot all the individual frequencies? The RTA would have to have a high input imepdance to do that. I want to measure the amp outs and not include the speaker system (including room gain, etc)

I'm not sure. But it is definetly something I've been meaning to try with my computer. Shawn (sfogg) says it's ok because the high impedance won't draw much current. This will give you the electrical sum of the amp-speaker interaction, but won't say much in terms of the actual acoustical output. If you'd like to look at your acoustical performance without the effects of the room and you have a computer nearby then you might consider looking into something like http://www.etfacoustic.com/

The more I thought about hooking up RTA straight to the amp outputs, I know it will work for the reason Shawn mentioned. I used to feed the speaker out from a 16mm projector into a line in on my mixer when our church would show movies. A line in with a pad can handle a pretty high signal level. It worked great. And it's a cinch the Moondogs aren't going to hurt anything. [] I'll just hook up a dummy load and try it. That way I wouldn't have to graph it too. I want to leave the room out of the equation first.

Bruce

[Erik Mandaville]

For Kevin (Cut-Throat):

Thank you!

Bruce: I suddenly remembered the other night that Thom M. and I had exchanged some email regarding that so-called ultrapath issue. I think he used it for awhile, but from what I saw in your amps, the 2A3 cathode resistor had been bypassed in the usual way (which I think I actually mentioned back when you first got the Moondogs....but maybe not, I don't remember.)

In any event, if you want to confirm that, take a picture of the output tube connections and I can tell you. It only involves a couple of connections, and is easy to put back. I think the amp is stock, though, except for the other changes in cap and resistor parts I described. Also, you might sometime like to try Electra Print OPTs. Some prefer the first Moondogs with the MQ iron, others prefer the EP stuff. The only 'better' or 'worse' that exists between the two, IME, lives with the person who prefers one or the other.

Erik

[Erik Mandaville]

Here is the Moth si2A3 with blue-glass AVVT 2A3 meshplates. It's been used with our pair of Heresy IIs in a downstairs system. SET amps can work very well with Heresies, and the AVVTs are wonderful tubes (not so cheap, but we found them at a price I couldn't pass up). I gave my old pair to another forum member, and was glad to find these new ones that both test VERY strong on our TV-7 and are completely free of unwanted noise.

[Parrot]

SET amps can work very well with Heresies . . .

No, not at all, not if it's high fidelity you're after. It's bad enough when someone says a low-watt SET amp will work with 104dB speakers, but the Heresies, forget it.

[Erik Mandaville]

When I got the parts and schematic to build the Moth myself (for a $avings), it was found that the only remaing top plates were for the 300B stereo amp. I used The holes for the potentiometers on the 300B version for a standby switch (left) and loudspeaker/headphone out switch on the right. The shorting jack used for the phones caused some hum (mentioned to me also by the designer) in headphone mode, and so I used the switch seen in order to independently switch the output transformer secondary connections between the speaker binding posts and phone jack. Headphones are totally quiet, which is pretty good for this type of amp -- but maybe not surprising since, unlike many single-ended AC-heated triode amps, the Moth uses regulated DC on all filaments.

The HeresyII/Moth combination is really nice, and can play louder than we prefer to listen -- without clipping distortion of any kind. Strings are particularly clear and resonant, and acoustic guitar and jazz is just awesome.

For information sake: The Moth is a direct-coupled amplifier that uses no interstage coupling capacitors. Output transformers are enormous things by Electra-Print (the same person who designed the original DRD circuit now offered by Welborne Labs).

Erik

[Marvel]

SET amps can work very well with Heresies . . .

No, not at all, not if it's high fidelity you're after. It's bad enough when someone says a low-watt SET amp will work with 104dB speakers, but the Heresies, forget it.

And we know you have tried this Paul... just give it a rest.

[Parrot]

The HeresyII/Moth combination is really nice, and can play louder than we prefer to listen -- without clipping distortion of any kind.

Total nonsense in the real world. What you mean is that you are listening at either extremely low levels and/or you don't recognize the clipping.

[Parrot]

And we know you have tried this Paul... just give it a rest.

I'm sorry you can't handle the truth. It is understandable when facts go against feelings that some will dismiss or downplay the facts, or even resort to personal attacks, which is a particularly prevalent tactic among SET fans.

But as I've said more than once before, facts can't be wished away. If an amp is distorting or clipping, one may not notice it, or may notice it but not care, but the amp is still distorting or clipping.

As Trey Cannon posted on July 11, 2004, after a different, long SET thread: Paul is right, low power amps, tube or SS, clip. That's why I tell everyone to use 5 times more power than they need.

[Cut-Throat]

You know what really irks you guys - You know that all of us SET guys have upgraded from Push-Pull amps long ago. In fact most of us have Push-Pull amps sitting in the closet unplugged. We really don't give a rats *** what you NOSValve and paulparrot thinks.

So just move along and someday when you grow up you might be able to afford a SET amp.

[Parrot]

You know what really irks you guys - You know that all of us SET guys have upgraded from Push-Pull amps long ago. In fact most of us have Push-Pull amps sitting in the closet unplugged. We really don't give a rats *** what you NOSValve and paulparrot thinks.

So just move along and someday when you grow up you might be able to afford a SET amp.

LOL! I hope you stay; you are a riot.

[oldbuckster]

You know what really irks you guys - You know that all of us SET guys have upgraded from Push-Pull amps long ago. In fact most of us have Push-Pull amps sitting in the closet unplugged. We really don't give a rats *** what you NOSValve and paulparrot thinks.

So just move along and someday when you grow up you might be able to afford a SET amp.

All this fine forum friendship is a bringing a tear to my eye..........Wow, feel the warmth.....Hey how about someone bring a SET amp...........and someone bring a Push-Pull and let the best amp win??????How about it............PROVE WHAT YOU SAY.....Pretty simple if you ask me.............COME ON........GET IT ON....

[Parrot]

Oldbuckster,

I've actually watched SET enthusiasts listening to woefully underpowered amps that were mushing the sound, but oblivious to it all, waxing poetic about the sublime perfection of their experience. It's amusing to observe.

[Marvel]

And we know you have tried this Paul... just give it a rest.

That's why I tell everyone to use 5 times more power than they need.

Perhaps he is. You just don't know, do you?

[pauln]

What a great thread! Duke, man of few words wrote a 20 line post on p27!

Now, what about Parrot aka troll...

[Parrot]

The SET meltdown continues. This thread shows that in the SET camp are

1) The deniers of facts

2) The stiflers of debate

3) The namecallers

4) The rude ones

While the old SS camp is barely represented at all. As Oldbuckster has stated repeatedly, it looks very much like it was all a SET up from the start.

[steve]

Paul

I have been none of the above..and I've "contributed" to this thread.I'm always looking to tweak my system, and at the time, the SET amp produces the most desirable sound I have heard on my KHorns. I am more than open to new amps, but at this point, not open to spend more money -without- auditioning first! As stated in other posts, I'd love to hear some VRDs, Crowns, etc. I tried McIntosh tubes, and for some reason, I didn't like it..not bad mouthing them, I just (so far) preferred the sound of 300B 8 watt amps..

As for facts, well..maybe the SET is clipping...if it is, I can't tell. I probably don't have it loud enough to clip! 85-90 db, maybe 95db peaks? At least that's what the meter says.

My biggest complaint is how fast digital recordings come on making the volume control knob too touchy! But that's another topic..

Steve

[coda]

SET has its flaws, but any aspect that is inaudible becomes more ad hominem than logical to sound quality. What is more interesting to SET listeners are the output restrictions inherent with push-pull that are audibly overcome with SET. The comparitive differences between the two become more apparent with certain gear. There's good PP, and there's good SET. It's as simple as that. Just read wikipedia with a grain of salt.

[oldbuckster]

The longer this MUD fest continues the more I Like my Sony SS.........OK, I'll put it up against any of you........All I see is TALK ,TALK ,TALK, Name calling, that's real classy, the real fact is IT"S A MATTER OF TASTE, and some of you have none. Make you point without calling people names, present some facts, prove your point like grownups, not kindergarden kids....................Hey Steve, glad your not part of this MUD Fest, UNBELIEVEABLE...................what a FARCE...........Marvel, this has to hard for you to watch this unfold, too......

[Erik Mandaville]

Craig:

"Sorry I just hate false advetising. If I purchased the amps in question and found out a school teacher put them together I would be upset."

With all that has taken place in the past, I admit I was a little surprised to see this. I really don't want (or need) to spar over it, but in fairness to the person for whom I did the work, I want to mention that one defintion of 'professional' has to do with one party (or person) compensating another for certain rendered services.

Kevin mentioned that I had done work for free in the past, and that is true. Quite a few forum members contacted me about quotes they received for repair work from professional techs that were grossly out-of-keeping with the actual hands-on time needed to complete the job. In a few cases, the qouted price for repairs was prohibitively high, so I did the work for free. I still continue to do minor repairs for free, but not for major projects.

The school teacher remark: Again, I'm not going argue with you. However, I would like to submit that I have personally repaired components that were built by those who would fit your idea or concept of 'professional.' Moreover, I have seen components built by 'hobbiests' that in terms of workmanship far exceeds that of many self-proclaimed 'professionals' by a significant margin.

The people for whom I have built or repaired components did not seem to mind that I am also a school teacher.

Erik