Short List of Amps I prefer over the Pass Labs XA25 or INT 25

I was confused because earlier you mentioned that tubes have more detail, but the masking of distortion is unrelated to the perception of detail.

Thank you for the clarification.

Masking though, AFAIK has to do with closely spaced frequencies. Hard to mask higher order distortion, isn't it?

BTW, I like tubes a great deal. :) I'm not attacking them I just want to make sure I understand the arguments.

@erik_squires To be clear I didn't feel you were making any sort of attack! Asking for clarification is not an attack, and I welcome it.

Masking is a tricky thing but AFAIK doesn't have to involve closely spaced frequencies; if they are not closely spaced the ability to pick out the lower level sound(s) is better. This is fairly easy to experience. One example of this is our ability to pick out information when there is something like white noise in the foreground; analog signals can have noise but we can pick out signals that are a good 10dB below the noise floor! (I suspect this has something to do with the fact that wind and water sounds are very similar; so this could be a survival issue)


It appears that the ability to pick out signals in the noise floor relates directly to amplifier design. Amps with zero feedback tend to have a noise floor that involves a fairly natural 'white noise' hiss; amps that run feedback tend to have a noise floor that consists of inharmonic information and intermodulations, into which it **seems** that the ear cannot penetrate as it can a natural noise floor. This might explain why amps without feedback can often seem as if they have more low level detail. This is an area that I also feel needs more research (one exception to this is if the amp with feedback has sufficient gain bandwidth product such that it is stable with over 35dB feedback; such amps are quite rare). 


At any rate, I did say that tubes have more detail, and that they manage this without being bright. However I wasn't suggesting that masking distortion was the reason. I was instead suggesting that the presence in the correct quantity of 2nd and 3rd harmonic content somehow contributes to the ear's ability to pick out natural detail in the recording (including soundstage information). While this is documented, exactly how this occurs is an unknown (AFAIK) and something which I find very interesting.

@atmasphere

I already know you are comfortable with having a civil discussion when it comes to nuanced technical topics.  My disclaimer (that I like tubes) was meant for those who read only the convenient parts.

Best,

E

Agreed. Discussion fosters new insights and I welcome differing
viewpoints. Life would be very dull otherwise.

FYI-You may have heard but loss of sense of taste or smell
can be early Covid symptoms.Tequila will snuff it out though.

Stay Well!

I have owned a couple of a Pass amps (including an INT-60, which a friend now has) and I still own a couple of First Watt amps.  I have also built two Amp Camp Amps (ACA), which are designed by Nelson Pass.  I respect Mr. Pass for his “different/subjective” approach.  The reason is didn’t keep the Pass amps was due to size and heat, they are big and hot.  Large Class A designs just don’t work well for me.  Nothing against the sound.

With that said, I have found a few amps that have a similar sound to Pass that I prefer:

• Nagra Classic INT
  
• Naim SuperNAIT
  
• Gryphon Diablo 300
  

The Nagra is refined with lots of air and ambient texture.

The Naim is smooth, organic and lush.

The Gryphon is dynamic, fast and detailed.  This amp, like the Pass, is big and hot, and those side fins can bite when it is moved.

The speakers and room, as always, play an extremely important roll.

@chorus : What speakers are you planning to use?

The Gryphon is dynamic, fast and detailed.

And to mention, they can drive any hard to drive speaker to it’s best, especially when the speaker loads dip below <4ohms, unlike anything else mentioned so far on this thread, except the D'Agostino.

Cheers George