About Pathos New Classic One

Hi All,
I recently buy a Pathos New Classic One after long research and listening sessions.
Unfortunately on third day the source selection knob was damaged (an internal spring was broken!) . The distributor in my country immediately change the device and gave me a brand new one.

But, there is very obvious sound difference between the old one and new one. The new one has a very obvious "hsss" effect, especially with old recordings, on live performance.

Those any one exerience this?

There is no other problem where the all ranges sounds very well and I am very happy with the device.

I realy don' t know how many hours the old (replaced) one work and burn the lamps. The new one supplied to me was absolutely new, and I almost listen it for 15 hours. Should I wait for 150-200 hours our talk to retailer immediately?

This is the second Pathos I listen, so I don' t know which one is real performance, :) ? What is you experience ?

For information:
CD: Onkyo (I will upgrade it)
Interconnect: Van der Hul Bay C5
Speakers: BW DM 602 S3
Speaker cable: IXOS
Power cable: still the original one, will upgrade, any suggestions?
I'm not sure I'm understanding correctly, but I'll give this one a try based on what I do understand you're saying:

If the hissing sound exists ONLY on older recordings this could very easily be tape hiss. Recordings made when technology was not up to removing tape hiss will likely exhibit a sound like you describe. This is completely normal and there is not a lot your amplification can do about that unless it has tone controls or an equalizer in line.

If the hiss existed on EVERY recording you played but NOT when the amp was idle (powered on but with no signal coming through it) I would STILL look at your source component (CD player) for the flaw.

If the amp makes the hissing noise with NO signal coming through it, this may have something to do with the amp. The tubes do break in during the first 200-300 hours and will tend to sound different (better) after breaking them in, but it has not been my experience that if they are noisy, that burning them in reduces the noise. From your description, and because the noise is ONLY on older recordings of live music, I do not think it is your amp. Your amp may be revealing a lot more than what you prveviously were using and therefore you are more aware of the sound. Tube amps do have a very low level hissing sound sometimes, but this would occur at idle if it is what you were hearing, and it is usually very quiet (especially with those 602 speakers which I don't think have a high efficiency rating). Your amp is a hybrid tube amp so I'd seriously doubt whether this were the case.

If you are concerned, take the CD's that have the hiss to your dealer, along with one that does not. Play those CD's on a good high-end system and see if you do hear the same sound. I'm betting you will.

Hope that helps!