Yet another bold claim...

So we all need dac 64's then eh? BD
Excellent deduction watson, and que TD

 

If you want "detail and resolution" I don't know of better option...

 

So did anyone ever explain what a null test is?! 'cos I must have missed that

 

and just out of interest, how would you guys say this Rotel compares to a Bryston like the 4BSST?

 

Measurement Shmeasurment, Ferrari Enzo tops 210 mph and has a higher top speed than the F2004 in reasonable down force configuration , but which one would you rather have a shot in?

 

Tenson,

The Bryston eats the Rotel for breakfast - I have owned both. I have also owned a Sim W3 at the same time as the Rotel and it is a superior product in nearly every respect.

Here we are talking about resolution. From what I understand of the null test, the idea is to get a silence, showing that no distortion has been added by the amplifier. Will that silence also reveal what has been lost I wonder?

 

We only had almost an entire 9 page thread about it

Michael.

 

Of course it will. If something has been lost then the output signal will differ from the input signal and you'll hear that difference in the null test output.

Michael.

 

So that'll be the reason for the term "very nearly silent" then will it Michael? Is what BD is hearing distortion or the lost resolution? How can you tell whether the resultant noise is from the signal or the amp?

 

Who wants an amp to be silent? If its silent, then you aint going to hear much music...

 

The resulting sound from a null test is always the result of the way in which the amp under test is modifying the input signal. If what you get is "very nearly silent" then that's clearly better than one that is far from silent. Once you get to that point though you really have to put the null test output to an oscilloscope to more accurately see the distortion signal.

Lost resolution is a form of distortion, so what BD is hearing could well be lost resolution, but if the amount being lost were large then you wouldn't get a "very nearly silent" null test.

Michael.

 

Thanks Michael.

If a lot of low level resolution was missing though, wouldn't the noise generated by this be quite low?

That's my only beef with the Rotel amps I have listened to, as you know I am a fan. Is it not possible that something with greater resolution, even when embellished with some even harmonic distortion, would sound more "real" to many ears?

 

as it happens, I quite like audiophile jazz recordings, but not crappy ones. Try the re-mastered Kind of Blue by Miles Davis. It may or may not need forgiving. That said, its highly enjoyable.

 

Yes, I suppose the difference (null test) signal would be pretty low if the level of what was missing (or being added) was very low.

Quite possible, and then we're getting back to the age old debate of defining just what is "accuracy" or "high fidelity". Even order harmonic distortion, even if it sounds nice or more "real", can't possibly be said to improve fidelity. It is, by definition, a step away from fidelity.

Those (such as Tube Dude) who have null tested and subjectively evaluated a lot of amps say that better sounding amps always have a better null test. I don't have enough experience to say whether I would agree with that or not.

Michael.

 

I think somebody needs to explain what they mean by resolution before this discussion can continue...

If we're talkin' the ability to not "smudge over" fine details (okay, not the best description...) then as long as the details are fine enough (and as long as that's all the amp is doing wrong), surely the null test show up very little audible distortion?

On the other hand, if Rotels are indeed "forgiving" and obviously round off the treble for a smoother, more relaxed sound (am I interpreting this right?) then that kind of distortion would surely show up quite readily on the null test? In which case it seems conceivable that what Merlin, WM et al are interpreting as "greater resolution" (in the case of the Sim over the Rotel) is actually some form of distortion that brings out details that a purely "accurate" amp would leave submerged in the mix. No?

And this brings up another important concept - the idea that an accurate amp is not necessarily the one that sounds best. In theory there is no need for an amp that isn't accurate - you want it to take the input signal, amplify it, and spit it out unchanged. But it seems possible to me that some people (a lot of people? most people?) like one or more of the various distortions (2nd order harmonic, who knows what else?), and would rather have an amp that produces such distortions than one that doesn't.

It's worth remembering that the human ear-brain mechanism is exceedingly complex and is completely different in mechanism from a microphone. Some of Jim Lesurf's excellent recent articles in Hifi News have served to highlight just how mysterious and misunderstood a lot of it is.

I suppose in an ideal world we would identify which families of distortions different people like, and have standardised labels/categories for amps that intentionally add such distortions , as well as having a "high fidelity" category for people who just want straight wire with gain. Or perhaps if we were really clever we could do it all in DSP before it gets sent to the amp, which would make experimentation so much easier and would allow us to use different "distortion configurations" for different albums, tracks, or even moods (though for marketing purposes we'd probably have to come up with a better term than "distortion configuration" ). This would eliminate an awful lot of confusion!

Sorry, just thinking out loud...

Dunc

[Edit: Michael, you beat me to it!]

 

I'm sure some is smiling to themselves in a more than mischievious manner!!!
Nice stab at it Dunc, You could use a full spectrum sweep, that'll show one or 2 things that may/maynot distort, however, you may be surprised to learn that a lot of 'quality' manufacturers do actually listen to the end result, and 'tweek' the sound to suit what they consider to be 'correct' for the product.
I have a 1062, I also had a I-5, the 1062 is a good amp for the cash £600 easily compete's in the £1k range, however Its not the Moon league.
As for front end soucres being at fault, it'll take more than a pair of custom wound isolation transformers & output tubes to put the 1062 in the same ball park as the Sim
Though those naimies looking for a decent amp that'll rock and go reasoanbly loud then 1062 is worth a long audition.

 

"In which case it seems conceivable that what Merlin, WM et al are interpreting as "greater resolution" (in the case of the Sim over the Rotel) is actually some form of distortion that brings out details that a purely "accurate" amp would leave submerged in the mix. No?"

Exactly!!!

If the idea is to reproduce as faithful as possible the human voice and the instruments made by humans... then you have no better option than a wire with gain. Period.

Just because no one can do it (Tube Dude is really close) we are not forced to accept distortion as a good thing. Less distortion means better amp. Your hears will tell you, otherwise you wouldn't need to change equipment.

Why do you change equipment so often (providing you have the money)? Why?

If anyone could tell me why I would be most pleased...

 

Wm,

The 1062 is clearly a better amp than the i-5.

I have an objective, not only subjective, indication of that...

You say you like the i-5 more and i'll tell you there are men who like other men. I like women... so what?

 

Merlin,
There is no point getting into a discussion with these guys (echoes of Antonio, I fear), since they refuse to provide a detailed (or indeed any) account of their testing criteria, methodology or results.
I suspect they don't do this because they can't.
This whole null test debate has been quite pointless so far.

 

BD,

Very seldom do I consider even remotely getting mildy uneven, I do however on this occation breaking that rule.
I fear the med sun has caught another victim, I feel on this occation, you should send the ampilifer for independent testing and calibration, then onto a mag for apprisal.
Failing that, do us a favour shut up, you are beginning to irritate, like a dosh of morcombe bay crabs.
Just out of interest, has the AA found your tireless devotion to 'odd' counter strikes a little bit tedious as well?, or are they just as anal?