Pass labs irony

[elihu11]

I know many won't find this ironic but I did.

I had spoken to a dealer that sells raidho about some speakers. He asked me my electronics. Of course I told him. He actually told me I should buy pass from him because they smoke the Ayre. My feelings are obvious about Ayre, so needless to say I ignored the advice.

I looked up their new Xs series amps to read about them and laughed when I saw the picture. The small indention was identical to Ayres design for most of the last 20 years. Either Pass copied them or Ayre did but I don't remember that on older Pass designs. Too funny for me. I took it as a hint.

[BillK]

All I can say is I have a good friend who has used Pass Labs products for years, sells some and is a Pass fan.

I mentioned that I was auditioning the XP-20, XP-30 and the KX-R.

Without a moment's thought he said simply, "Get the KX-R."

[PlanarSpeakerFan]

Ayre makes excellent components. Beautifully designed and constructed, zero negative feedback circuitry. I used to own a QB-9 DAC and spent many happy hours listening to and enjoying it.

Ken

[jax4736]

Listing to my QB-9 DAC right now. My C-5xeMP isn't getting much play since it arrived...

[elihu11]

Just so others can see what I am referring to I have posted pics.





Where the LED light is. I guess it still surprises me they are so similar.

[junker]

I wouldn't kick either out of bed...

[cma29]

Originally Posted by junker

I wouldn't kick either out of bed...

[elihu11]

I would. I am monogamous.

[Box860]

While the casework may bear some superficial similarities, it's what's inside that counts. Both Ayre and Pass Labs make very fine high end gear. But Charlie Hanson's design philosophy is quite different from Nelson Pass's. As mentioned, Hanson eschews negative feedback. Pass finds negative feedback useful: "We use negative feedback in audio amplifiers to stabilize the gain, increase the bandwidth, lower the output impedance and lower the non-linear distortion. It is the aspect of reducing the distortion which tends to generate the most controversy – negative feedback is very successful in lowering distortion to very tiny numbers as measured by distortion analyzers." https://passlabs.com/articles/audio-...n-and-feedback.

I lack the technical knowledge to judge the relative merits of each approach, but clearly this hobby demonstrates that there are many ways to achieve great sound. I suppose it all comes down to personal preference and synergy with one's system.

[junker]

This is disingenuous. In the paper you cited he weighs both philosophical approaches to amplifier design. Take a look at his conclusion at the bottom of this post.

Throughout my literature he repeatedly states that he believes in minimal feedback, and only in so much as to balance the distortion:

As always the goal has been the best musical and objective performance possible with minimal parts in the signal path and minimal feedback. This process is not completely quantified, and many of the improvements are the result of trial and error and extensive listening.

He more thoroughly discusses his opinion on the use of feedback in this Technical Paper / Whitepaper that you cite - or rather, take a "sound bite" out of context in the above post.

https://passlabs.com/articles/audio-...n-and-feedback

Conclusion...

"By contrast, it appears that if you can make a single stage operate at .01% 2nd harmonic with a single tone without feedback, you could also achieve the .1% peak in the complex IM test.

I like to think the latter would sound better."