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Hi-End Home Tube Amp for Sale

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Spiritzly

Member
Joined 2002
That is a good question I would have to address with the designer. I think his many years doing everything from cheap old stuff to boutique designs has led him to chose whathe has chosen. I'm not so sure if the cap change would really do anything, but it is more a question for the man in charge of his knowledge in the making of this fine amp.
 
S

Spiritzly

Member
Joined 2002
EC8010 said:


Loudness is a subjective thing and clipping on a transistor amplifier tends to be nasty and immediate, whereas some valve amplifiers can still sound good 3dB into overload.
Click to expand...

That's a good point. Why would it even matter that a manufacturer states how many watts something produces when they should be stating the amp's relationship to loudness? I.E. "We have tested our amplifier on the Magnepan series of loudspeakers and the loudness level is equal to such and such 600-1000 watt amps by Krell, Levinson, etc." People always seem to look at watt figures when they never tell the entire story except when the big amps are draining your electrical current.

I was very curious about that 3db overload thing. Are you saying that the clipping is so gentle that at high volume levels you cannot hear the amp clip? I've driven about 10 tube amps I have owned to clipping levels and while they don't try to kill me like the SS amp does:) they still don't sound good to me as I like to hear a clean sound that has zero strain at all. Just curious if what I have heard in these amps have been that 3db extra before they start to sound like they are clipping...or are close enough (I can tell when an amp is approaching clipping).

Thanks for more info on the 3db thing.
 
EC8010

EC8010

Ex-Moderator
Joined 2003
It is not legitimate to describe an amplifier's power by attempting to define how "loud" it goes with a particular loudspeaker. Loudspeakers are complex loads and although they look vaguely like a resistor, they are all different in different ways. It would be perfectly possible to design an amplifier optimised for a particular loudspeaker. Any sensible designer of amplifiers for active crossovers does this. The only "fair" load is a resistive load, even though it isn't terribly representative.

Obviously, the 3dB thing is subjective. Nevertheless, my impression has always been that a valve amplifier can go just as loud as a transistor ampifier of twice the power (3dB). Now, as to your "zero strain at all" requirement, clearly, that implies no clipping. Now we're down to subjective tolerances. I'm extremely intolerant of upper bass blurring, midrange harshness and treble "tinsel". I feel that very few transistor amplifiers avoid those problems. The tricky thing with contemporary valve amplifiers is to achieve modern clarity without including the previous problems.
 
S

Spiritzly

Member
Joined 2002
EC8010 said:
It is not legitimate to describe an amplifier's power by attempting to define how "loud" it goes with a particular loudspeaker. Loudspeakers are complex loads and although they look vaguely like a resistor, they are all different in different ways. It would be perfectly possible to design an amplifier optimised for a particular loudspeaker. Any sensible designer of amplifiers for active crossovers does this. The only "fair" load is a resistive load, even though it isn't terribly representative.

Obviously, the 3dB thing is subjective. Nevertheless, my impression has always been that a valve amplifier can go just as loud as a transistor ampifier of twice the power (3dB). Now, as to your "zero strain at all" requirement, clearly, that implies no clipping. Now we're down to subjective tolerances. I'm extremely intolerant of upper bass blurring, midrange harshness and treble "tinsel". I feel that very few transistor amplifiers avoid those problems. The tricky thing with contemporary valve amplifiers is to achieve modern clarity without including the previous problems.
Click to expand...

I think you said it perfectly. I have a person that has been working for almost 3 years to nail down a transistor based design. Another 4-6 months to go...but this is an approximation that continues to go on. I've heard his 5 watt transistor amp compared to his 5 watt dual monos (tubes) and the tube amp seemed to have a slightly lifted soundstage while the SS amp had a more abundunt bass. Tonality/speed/imaging/etc. were all the same. These two things mentioned were also so insignificant that I would never know the difference between the two (no a/b testing...just swap one in for the other). I heard nothing wrong with either amp and they are "unfortunately" the best amps I have heard. I say unfortunately because my speakers need about 100 valve watts and it's a shame there is no speaker aside from the rediculously expensive Tad stuff that I would care to use besides the speakers I have.

Thanks again for your writing. It is very good and helpful.

Regards!
 
adhoc

adhoc

Member
Joined 2005
imagine a sine wave. now amplify it into clipping

in a ss amp, the 'top' and 'bottom' of the sine wave will be lopped off, leaving a flat 'plateau' on top and the corresponding analogue on the bottom of the sine wave. not fun.

for a tube amp, simply replace the top/bottom of the sine wave with a slope of a gentler gradient. not as good, but certainly light years ahead of the 'plateau-ed' ss sine wave.
 
SY

SY

Ex-Moderator
Joined 2002
SYclotron.com
Yes, I've seen that. Unfortunately, I've also seen what a tube amp's clipping looks like using real amps- pretty indistinguishable from SS, at least looking at the traces on a scope. The exceptions are tube circuits where soft-clipping is designed in, but that's also true of SS.

Now, SE circuits (tube or transistor) may be different in that one side could clip before the other, but push-pull amps will almost always clip symmetrically. And hard. The key, and this is something that Morgan Jones correctly makes a big point of, is how fast the circuit recovers from the clipping incident.
 
anatech

anatech

Administrator
Joined 2004
Paid Member
Hi miklos,
If notheng else the output transformer makes the difference.
Click to expand...
For sound quality yes, but clipping is clipping.

SY made a valuable point. Overload recovery makes all the difference in the world with music. The amount and application of feedback will determine how hard an amplifier is driven into clipping. Various stages can be cut off or saturated and it takes some time for the operating points to normalize. This is true for both solid state and tube based designs.

The best way to understand is to stick some amps on a bench and run them into clipping while watching the results (with a scope, hopefully not a visual display). ;)

-Chris
 
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