Amplifier brand/designer with the most unique and consistent “house sound?”

If you get rid of distortion and phase shift across all frequencies, will all amps sound the same?  Should they?  Even with different topologies, parts?  No more house sounds?

If their output impedance is also the same then at that point, yes, they will all sound the same assuming their power supplies are up to the task.

I would not characterize doing this as a mathematical extreme. Its simply what you do if you want to get it right.


The key is getting enough feedback and at that point it won't matter if its tube, solid state or class D. This is almost impossible with tubes as there are usually too many frequency poles resulting in a low 'Phase Margin'. If the phase margin of any amp is exceeded when feedback is applied, the amp will go into oscillation. This is one reason why tube amps tend to have less feedback than solid state, the other being that they are also inherently more linear and don't need that much feedback to have acceptable distortion figures.


Designers who have been up to the task of installing enough feedback in traditional solid state designs are rare. But it appears that the Benchmark and the Soulution are two amps where this is exactly what has been done.


In class D this is possible though a different means which is to add so much feedback that the phase margin of the amp is exceeded, causing it to oscillate. The oscillation is then used as the switching frequency. Such amps can employ quite a bit of feedback and the sound of them is really all about how well the power supply is built.

@atmasphere

Different resistors, capacitors, wires endow amplifiers with unique and often predictable coloration/qualities.  Do these components vary in their distortion/phase attributes in predictable/measurable ways?  Or are other characteristics of these parts contributing?

@optimize
“It would be interesting to compare ACA against a ncore. NC400 that is on the other end of the scale and is one of the best measuring amps.

I guess that NC400 is one of those amplifier without any house sound with almost no distortion at all.”

I built the Pass ACA amp, the 1.8 with 8wpc, and use it in my office system. I also read the review on ASR about it before I bought and built one.. I’m driving a pair of NHT S1’s with them rated @86db sensitive.. This is when ASR lost all credibility with me as the ACA amp just sounds GLORIOUS and produces all the volume I need and then some !! I also owned a pair of Bel Canto Ref600 monos based on Bruno’s Hypex NC400 modules for a couple of years. I’ll take the old inefficient Class A topology w distortion and low power sound over class D specs and sound anytime ! I liked your system vid... sounds good even with crappy phone..
Here is one of mine.. my first iPhone crappy recording..
https://youtu.be/vqMqGV342m0
https://youtu.be/yB12zq-UKHI

@mikem thanks for the insight and your kind words.
Good sound you have there! 😀🎶🎵

Different resistors, capacitors, wires endow amplifiers with unique and often predictable coloration/qualities.  Do these components vary in their distortion/phase attributes in predictable/measurable ways?  

Yes. Its also predictable that if a part such as a capacitor or resistor does not measure as well as another part of the same value (assuming that the values are identical) that when the inferior part is installed the circuit will not perform as well. Sometimes the differences are very slight, sometimes not, depending on where in the circuit the part is installed, since certain parts of the circuit are more critical than others. 

For example I've seen capacitors of different types but the same value have an easily measured difference in high frequency bandwidth. Resistors of course can have lower noise- and this is no secret or weird snake oil; Ampex used low noise resistors in critical points of their tape machines back in the 1950s.