Pass Labs amps questions

I owned different Pass Labs poweramps and monos in the last 7 years of time. I also owned the XP-20 for 2 years of time.

I owned the XA100.5 for 2 years of time as well. Now I own the X350.5. I use this one with the latest Purist Audio LE luminist powercable. This gives the 350.5 a totally different level. The mid freqeuncies are more souding like they do with XA series. ( I owned 3 different XA power amps of Pass Labs) I love the extra controle and details the X series can give.

We did a test with the AR 5SE pre amp with the X350.5. People think it is a very good preamp, but mannnnn it is a very poor pre amp.

What did it do connecting with the X350.5?

- the speed, controle en timing went to a much lower level.
- the details became a lot less
- the stage depth and width became a lot less
- the individual focus of instruments and voices became less sharp.

Not even for free I would use the Audio research ref 5SE as a pre amp. The person who owned the AR Ref5SE could really cry. I never forget the look in his eyes. The truth can be hard and confronting.

My personal opinion about Pass Labs is they create stunning poweramps and create good pre amps. But not stunning ones, as they should be. They are not good enough. But AR pre amps ar not better!!

* my next Pass Labs will be 350.8, but probable the X600.5 monos.

" My personal opinion about Pass Labs is they create stunning poweramps and create good pre amps. But not stunning ones, as they should be. They are not good enough."

bo1972,

I agree. My Pass amps were definitely at a higher level than Pass preamps I've owned. But you don't give an alternative. If not Pass or ARC, what preamps do you like with Pass amps?

That is a good question. I had a lot of email contact with Desmond Harrington (President Pass Labs) between 2009 and 2015.

In 2009 I said to him; Pass Labs needs a more realistic focus of instruments and voices. I call it intimate focus. Because instruments and voices are in real very direct and small in proportion.

I owned the XP-20 for 2 years of time. It is a good pre amp, but good never will be good enough in my world. Only the best counts and the rest doesn’t matter.

In 2010 I started research in measuring the acoustics. I created Statement Audio Pro measuring. In 2012 I bought an Onkyo PR-SC5509 pre amp. With my measurement in 2012 I already could outperform the XP-20.

I told Desmond about it, he wanted to buy and test one for himself. I said without my knowledge and insight it does not make sense at all. I had to laugh because it is a new and different way of using and thinking about audio.

I improved the way of measuring in the last years a lot. We modified and used new parts and techniques inside the 5509. We used for about 2500 euro on parts inside.

I use the beste digital lasers and we work so much more precise than the way people work in audio. Now we are at a point we will sell the way of measuring and the techniques we created.

It will bring audio to a much higher level than people know at this moment. It can create a much higher level out of a Pass Labs poweramp. You cannot compare it with a XP-20, it is superior in all parts you judge sound for.

You can create stealth low frequency with it. This sets a subwoofer in phase with the loudspeakers. But the energy is exactly were it is at the recording. Even when the subwoofer is 3 metres from this part.

It eliminates the acoustic problems in a room, but it also is able to let you hear much more details of a recording. This year I have done a lot of research in diversity in sound. Because this is the most important part to create emotion in music. Even in a worse acoustic you can create a sound you never would expect be possible in that kind of room.

With different parts and measuring we are able to create more diversity in sound. This will let you experience more emotion during listening. It reveals much more diversity in sound of voices and instruments.

Based on a much better timing the energy of strings can be felt in the air. It gives instruments and voices a real 3D shape. My clients call it an addictive sound.

Audio is being created by trial and error. I call it: audio cambling. Because is owns no foundation why the sound and stage is what you hear.

That is why we work by Tru-Fi. These are 8 parameters you judge sound for. By labeling each part in your set on properties you can understand why the stage and sound is what you hear.

When an audio system owns all parts of Tru-Fi it always owns a higher level of emotion. Because Tru-Fi is based on the human emotion.

The emotion is inside of the music. And you need the right properties to be able to let people hear these properties which create the emotion of the music.

That is why we build an audio system by properties. This allows us to understand why the stage and sound is what we hear. This makes it so much more effective than any kind of trial and error.

The Pass  first watt if you have efficient Loudpeakers the F6 .I had a SE model built  using  premium parts VH audio output caps.My speakers,Salk Budd Fried -SE  are around 89-90 dB but 4ohm.
With my amp 25 wpc 8ohm, double that  50wpc into 4ohms  my amp using Jensen Input transfotmers , Matched Jfets,  and Mosfets outputs a true Dual mono design.I have plenty of power running in pure class A .
Very detailed warm and musical.