Let me end the Premp/Amplifier sound debate ...

@rauliruegas 

"  to remember Julian Hersch from Audio magazine and his very unscientific view that all amplifiers sounded the same once they met a certain threshold.  Now the site Audio Science Review pushes the same. "

When they have zero distortion, then by definition they will sound the same.
It is doesn’t take a lot of higher order harmonic distortion to sound pretty vile.
And a lot of low order harmonic distortion is hard to identify easily.

If we have one amp with only 2nd order harmonics, and another with only the orders of 3-N…. If their SINAD values are same (not zero), they will sound way  different.

So SINAD becomes most useful when the value is getting towards zero. If it is a long ways from zero, then we have a preference for the type of distortion that is listenable.

Maybe Mr Hirsch was hopeful that the ”certain threshold” was going to arrive sooner?

Dear @holmz : I’m not talking of theory as you and other gentlemans but about what we live day by day and what we listen through our room/systems.

The true is that does not exist measurements that can explain with certainty why we like what we are listening .

In theory everything could be measured but in the audio real life those measurements does not exist and if exist any then any of you that like so much the theory just shows one real example with tests/facts: not theory.

Zero distortion? in which galaxy?, I’m not talking of " illusions " but real life.

If some of you can’t prove with real facts what you are posting then is better to take away that " scientific " attitude and come back to the " land " come back to live your real life.

@erik_squires posted: " To your own self and your own ears/brain be true, "

Today we listen and experience what we have we can’t listen to " illusions " or hypothesis.

It’s true that in the same quality range of design several amps with more or less similar measurements will sound alike but never the same. I think that we have to use our common sense at the end science came and comes by the common sense those gentlemans used to their results.

I think and said several times that to be truer or nearer to the recording we have to have every kind of developed distortions at minimum. Even that two different room/systems coul have distortions at minimum will not sound the same: different kind of distortions/colorations.

I can know yet measures in a preamp/amp can tell us hw that units sounds for our brain. Could you or any one explain it with facts?

R.

In those vintage years electronics were designed and builded using the active and pasive devices that existed. Designers have not " hundred " of options about and along that the today high-end meaning was non-existent so de electronics designs were manufactured with way different targets than today units

As some one who was involved in the daily design and manufacturing of electronic equipment in the mid to late 1980’s when Julian Hirsch was still very much alive and well, I can say this paragraph has been based with very little actual knowledge of the manufacturing supplies of the time, let alone the brands that flourished then either.  To give you some sort of reference, the first CD was released in 1982, but analog semiconductor electronics had been flourishing for a long time.

You make it seem as if we were still making transistors by hand.  The manufacturing of semiconductors for analog electronics was as robust as it is today. 

@erik_squires : I know that over time bipolars, fet, mosfets, resistors, capacitors improved in several ways. Nothing is steady in audio and especially with manufacturer suppliers. All devices improvesd? maybe not but many did it.

I look your post as trying to argue or trying to tall me I’m wrong.

In my posts I posted: I can be wrong. So no problem in this issue, fine with me.

But reality exist: today electronics are and have higher resolution than in the past and not only because past electronics designs were manufactured with way different targets than today high-end units but because the today improved part devices .  At any period of time exist good, excellent and average designs.

I can see in your vitual Agon system that you use today " magic " caps. Why's that?

Btw, I owned the Luxman C5000 ( I neme it because you own Luxman. ) that in its time was a very good unit but can't compare with today units.

Anyway, measurements are an excellent tool to help audiophiles to choose the " best " alternative to match their systems’s targets and self priorities.

R.

@rauliruegas 

My point was very narrowly focused.  You made the 1980s sound like the dark ages of semiconductor manufacturing.  The reality is that it was nothing of the sort.