What to look for in a power amp?

Gregadd said:

Specs for Spectral DMA260. http://www.moremusic.nl/spectral/dma-260.html

now that's fast!

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Do owners need an amateur radio operation license to use it?

tomelex said:

Don, just chatting in agreement with your post.

I am all for feedback done the best it can be, but troubled by the fact that a good tube unit, without feedback and with a bandlimited output transformer, used within its limits, can engage ones soul on music that is not too complex...ie jazz and a lot of older rock and roll. Full orchestral works IMO need solid state to even attempt to sound right at any realistic volume levels.

Tom

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Can not disagree with you more. Please tell us what tube amps you're referring to. Or course a 3 watt SET is not going to cut the mustard.

Most of us feel that tube amps sound 2x as powerful as any solid state amp. I'll put any high powered ARC, cj, VAC, VTL amp against your high powered solid state amp of choice. Sorry but it's no contest. Nowadays it's not even a question of quantity vs. quality. Tubes capture both qualities.

FYI, have a listen to an ARC 210 or 610T, VTL 450mk. 2, 750 or Wotan, or the cj ART. You're going to be mighty surprised.

MylesBAstor said:

Can not disagree with you more. Please tell us what tube amps you're referring to. Or course a 3 watt SET is not going to cut the mustard.

Most of us feel that tube amps sound 2x as powerful as any solid state amp. I'll put any high powered ARC, cj, VAC, VTL amp against your high powered solid state amp of choice. Sorry but it's no contest. Nowadays it's not even a question of quantity vs. quality. Tubes capture both qualities.

FYI, have a listen to an ARC 210 or 610T, VTL 450mk. 2, 750 or Wotan, or the cj ART. You're going to be mighty surprised.

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Myles

Since it is a matter of preference, one cannot ask you to prove anything. I must simply suggest that the word "any" is too strong in

Most of us feel that tube amps sound 2x as powerful as any solid state amp. I'll put any high powered ARC, cj, VAC, VTL amp against your high powered solid state amp of choice.

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.
I have been in this hobby for a long time and nowadays the better SS and Tubes sound more alike than different. I will add, in passing, that the more celebrated amps nowadays seem to be SS ... but hey, if you prefer tubes .. more enjoyment to you ...

FrantzM said:

Myles

Since it is a matter of preference, one cannot ask you to prove anything. I must simply suggest that the word "any" is too strong in .
I have been in this hobby for a long time and nowadays the better SS and Tubes sound more alike than different. I will add, in passing, that the more celebrated amps nowadays seem to be SS ... but hey, if you prefer tubes .. more enjoyment to you ...

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I agree with you, Frantz. I've heard most (not all) of the high end tube amps, including, without limitation, Lamm, ARC, VTL, CJ, etc., and most (not all) of the high end SS amps, including, without limitation, Spectral, Bryston, Halcro, etc. I would exclude from the discussion those tube or SS amps which are purposefully designed to deliver something other than neutral/flat, which IMO should not be considered high end. But for the rest, play any of them at less than clipping volume, blind so as to eliminate all of the biases, and the differences are subtle to none. Those slight differences are what result in a person's flavor choice.

Thanks Tom.


Without getting into the rest of it, I'll just comment that very few tube amps have no feedback, though most have very little compared to tyical SS amps, at least in my experience.

Yes, always some impedance or resistance somewhere, whether rp or rk or re or some capacitance somewhere blah blah. It is funny how folks can be anti feedback and not understand the real deal about a triode.

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Interesting thought Tom. Can you explain this to my very simple mind

Me loves harmonics

Do continue Tom por favor.

Thanks Tom

Nice job, Tom, thanks!

Only one correction, I think: "Robert" Pease...

Tomelex

I have a hard time reconciling what I think I know about feedback with what the person describes as "internal feedback". Feedback is taking the differences between the input and the output (The distortion if you will) reversing it (changing its polarity) and feeding it back to the input... I don't see how the triode accomplishes that ...
Second the triode linearity is indeed true but the output of a triode has severe limits one of them Power, thus the development of multi electrodes tubes. Also, one could say that most amplifying devices are linear within a certain region, MOSFET for example region of "linearity" is quite broad when compared to a regular bipolar transistor. This region, interestingly is often called the "Triode" Region.
Feedback, is quite decried but it has its good uses one of them is to align/match device parameters... it is for example very difficult to find transistors or tubes with exact matched parameters.. A certain degree of feedback brings the parameters of the circuits more in line, make them more equal... When TIM was discovered the culprit was excessive amount of feedback which while allowing great measurements of THD and FR, ultimately produced great amount of Transient Intermodulation Distortion. It was thus seen then that reducing the feedback reduced TIM... I am not sure that removing feedback entirely is always a good thing as it introduces other problems, namely limited FR and increase in intermodulation and THD.. As always it is a matter of balance and great designers balance their circuits/designs as to take several conflicting parameters and constraints into an harmonious whole.
In the word of Forrest Gump .. "And that is all that I have to say about that"