ATC P1 amplifier

50ft of interconnect!!!!!
To try first without throwing money at this.
Just as an experiment, move everything together to try just 1 or 2 meters of interconnect, see if that fixes your lack bass problem.
And what preamp are you using? As your amps have just 10kohm input impedance, so if your preamp is capacitor coupled with the wrong size cap this could also cause an early rolloff in the bass in conjuction with the 10kohm input impedance of the amps.

Cheers George

I have to agree with George that's an extremely long cable run, particularly for a single ended interconnect. Definitely try a shorter cable. Something else to consider your driving a high sensitivity speaker with very benign impedance that was designed for low power tube amps with a 150 wpc digital SS amp. It may simply be a poor amp/speaker match.

Even with balanced cables if the pre/source is capacitor coupled, the same bass roll off problem will occur if the cap is too small with the 10kohm input impedance of the amps.
This is why I asked what pre/source is being used to drive the amp?

Cheers George

Hi guys.

I really surprise because my subject was about the ATC/P1 amplifier, not the length of my cables.

So, let me precise some little things. I worked in recording business few years, and trust me, 50 Feets of balanced (XLR) cables is a really common things. It's very interesting too see some Audiophile people 'panicked' with this sort for of things. It's really not a problem.

But when you need to have long distance cables you must choose correctly your devices and your cable. I am totally agree with that. The design of my listening room (including the equipment) took me 1 years, and another to build the room. I don't know how many sound engineer built a listen room with 2 helmholtz resonators, but i did ! So trust me, my design is solid.

Now, back to the P1. After 150 hours the sound i now open, deep, with a good soundstage. I am not sure if the sound will continue to change but it seem to be stable. I am really impress by this little amplifier. It's not dry, or difficult to listen. The sound is warm, really quick, and neutral. Woow.

The match with the Audio Note AN-J speakers is perfect.

What about the bass ? The bass is now totally in place. I have a little drop from 125 hz to 20 hz, but with a bookshelf speakers it's normal. I will adjust that with a subwoofer.

My 2 cents