Problem with aleph p 1.7

[gabflo]

Somebody with carried out the aleph p 1.7 of veteran? Did you have problems after the assembly?

[wayne325]

Non - mon Aleph P 1.7 a fonctione la premiere fois. Je suggere de
commencer verifier la CCS et la DC voltages.

Aussi par verifier 3 fois encore le PCB et les pieces !!!!!

[gabflo]

I wayne 325,
Thank you for your answer, this weekend, I will check the voltage on the psu and the assembly. I will give you my result.
With soon.

[gabflo]

Now it functions, but I have another problem on a way, I have a strange noise, and with the osiloscope it appears an unhooking, I changed all the condensers, the irf 610 and the irf 9610 and the noise is always there. Here is a copy of the signal

[gabflo]

another picture.
Mrs Nelson Pass have you got a idea ?

[zei]

what kind of noise? Can do describe it?

/Z

[gabflo]

I zei,
it's a kind of spitting or whisper on certain frequency. Firstable i think it's irf 610 or irf 9610 generate noise, but after change i have the same noise. I change one by one the 10µf and the 680p and ztx 450 and ztx 550 but nothing change. I verify the ground but it's good.I don't know any more what to make, because the other way functions very well .

[gabflo]

My problems are caused by oscillations. Nelson Pass suggest to add a 221 ohm resistor on the output side in one of the diyaudio thread, but without result. It's necessary to add a condenser between 10pf and 400pf, to make test to see whether the band-width does not decrease.

Now the sound is formidable, much of depth, more details, my blocks quad as never as well functioned.

I continue my investigations and the pictures will follow.