Yet another bold claim...

Joel - I hope you're not including me with "these guys". Yes, I find the idea of the null test pretty compelling and yes, Tube Dude's amp does sound very good and also has a very good null test but I haven't become all evangelical about it (at least I hope I haven't given that impression).

BD, have you null tested the Sim i-5?

Michael.

 

I think this is where all this accuracy argument falls down, we are never going to get an accurate picture as soon as you bring a microphone and recording device into the equation, we will NEVER get accurate, the closest we can get is a facsimilie, when considering distortion and such, forget it, as my analogy with the Enzo and the F1 car, one will measure better than the other in top spedd, the enzo may even be quicker above 180mph due to aerodynamics, but i'd still rather have a shot in the F1 car, wouldn't you.

We've had accuracy arguments before, and IMO it's a load of tosh, you buy the kit that you like the sound of, other wise you are daft, run in and such is crap, it should blow yer socks off as soon as you plug it in, otherwise save yer money and keep what you've got, not saying it won't sound sweeter as it warms up/burns in but it should be obvious from more or less right from day one. It makes no difference what the measurements say, buy the best sounding kit at your budget that you can afford sit back and be happy that it floats your boat, who cares what the measurements or others say, if ye like it ye like it, simple.


I don't change equipment often BD, but then I don't look at the measurements, I just bought the kit that i liked the sound of, go on try it it works, will save you having to go through so many changes yourself, instaed of trying to find an amp to make your speakers sing, why not just buy singing speakers in the first place, if you don't like them enough with the amps you've got then maybe they are not really to your taste, my speakers have been driven by a few amps for various reasons, (none of them cause I was changing anything), and to be honest each time they have sounded great.

Maybe you need new speakers, some guys round here seem to like Meadowlarks, have you tried them?

 

Having been to Tube Dude's lab I'm quite sure he could give a very detailed account of his testing criteria, methodology and results. To do it in English however might be a challenge, as I know how difficult it is for me to write that kind of stuff correctly in Portuguese.

I'd be willing to translate any such account from Portuguese into English though.

Michael.

 

We're comparing the input to an amp with the output and showing that the only difference is gain. At least offer some argument why you believe that an amp that only has gain into a real load is worse than an amp that distorts into a real load?

This is a fatuous analogy. Just because F1 cars top out at just over 200mph on the fastest circuit they currently run on doesn't imply that this is their terminal velocity, put a longer gear in and they will go faster given more space.

Paul

 

Quite. No one here has been able to offer such an argument.

That may well be, but in this case we're merely talking about accurately reproducing the input signal into an amp, but with gain. Surely that should be the goal that every amplifier designer should strive to reach?

Michael.

 

This would be very good.

 

And that includes TD and BD, since they have offered up no figures to back their claims.

 

Paul

My first point was I agree slightly off topic, but this whole pointless debate seems to throw up the accuracy argument, and I still believe that accuracy is irrelevant, it's wether it sounds pleasurable to the listner, that is the big picture nothing else matters, everything else is just conjecture, this offcourse is a different argument if you happen to like the sound that 100% accuracy gives you, but that's subjective.

I refuse to be moved on this point so won't rise to any silly arguments, these are my beliefs full stop.

The F1 analogy i posted earlier stated the difference between an Enzo and an F2004 in reasonable downforce trim, and I still think it's a good one, as I'm sure a Null test isn't the only measurable parameter of an amps capabilities, just as top speed isn't the only way to compare cards, it's a lot more complex rthan Top trumps.

 

Mike my argument doesn't disagree with much tha's been said, i just believe it to be irrelevant, BD likes the rotel it measures well, and he thinks he likes it better thn the sim, if that's what he prefers then who are we to tell him he's wrong, WM prefers the sim, yet both still give the same measurements, my point is, some may like the sound of "wire with Gain" for others it may not float their boat, maybe thaat's why Hifi is tuned by ear and not oscillascope, it all boils down to wether you like the sound it makes, nothing else matters.

 

I'm not quite sure why you think TD and BD need to offer up valid counter-arguments for their claims .

Accuracy cannot be irrelevant if what we're trying to do is high fidelity ie, an accurate reproduction of the original sound. If we could at least ensure that our amps were 100% accurate (wire with gain) then we could start worrying about the problems in the rest of the chain of recording/reproduction.

If one is going to be serious about enjoying hifi and music then I really can't see how striving for the most accurate reproduction of what's on the CD/LP can't be a primary concern, otherwise we could all just listen to iPods. Afterall, they're very enjoyable to listen to.

Michael.

 

Speaking of Ipods, I have a cunning plan !!!!!!!!!!!!!!!!!

 

There are no counter arguments involved.
TD and BD should provide some proofs of what they say and how they came to their conclusions.
This is not unreasonable.

 

I'll speak to Jorge (TD) and sort something out. What was measured, how, oscilloscope traces etc. From when I was there and had saw his amp on the scope and then later an Orelle and Audiolab integrated, I don't remember the exact figures but the measureable null signal on the scope was in the order of 100 times smaller than either of the other two amps. Using a 2nd amp to "listen" to the null signal is no longer useful with Jorge's amp as the null signal is so so small as to be inaudible. This was not the case with the other two amps which had clearly audible null difference signals.

I can't speak for the null tests that Vasco (BD) has done at his place.

Michael.

 

I would like someone to publish some data showing comparative results of these tests covering the amps that have been mentioned.

That would seem to be a reasonable request given the scientific nature of these claims Michael. And it would also be good to get a grasp on why amplifiers exhibiting relatively high THD figures continue to prove popular with well heeled audiophiles and hobbyists alike.

After all, didn't we have this whole arguement back in the seventies and eighties following the Japanese THD wars? Would you first null test an amplifier prior to listening or vice versa? And how would one result subjectively affect the other?

 

I would think it would always be better to listen first, write down what you think, then null test. The null test (if the difference signal is measured on the scope) is totally objective so can't be affected by what you heard.

Michael.

 

Phasers on stun

 

bring about ensign, lock all weapons on target, wait till you see the whites of the eyes, the full spread maximum yeild

 

Mr. Chekov, bring her round, Spock, Photon torpedoes at ready. Await my command.

 

Amps probably all sound the same, anyway. Except when you can see them (of course).

http://groups.google.com/[email protected]&output=gplain

 

that's my argument answered then Mike is it, if you listen to it first, then why bother testing it, as I've stated all the measurements under the sun make not a jot if you don't like the sound it makes, valve amps seem to thrive on distortion, but some folk love em, that's all thats important.