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vivanco 31st December 2012 10:40 AM

please help me
 
dear friends I have a problem with my aleph 30,,, in particular the following has happened: after completing the assembly of components on the PCB and wired everything inside your case, at the time of testing I found that one of the two channels did not work, because its speaker protection circuit did not give consent for the function, I ran trouble shooting which showed that the pCB had a defect of the incision, it was short of the pad (-V25) with the source of IRFP9610 of the differential, after removing the short between the two tracks, the situation has changed, in fact the speaker protection circuit gave the consent for operation, but when I connect the cable from the preamplifier (aleph P1.7), the circuit speaker protection goes into protection again ..... however if I not connect the input signal, everything seems to work because touching with fingers the XLR jack you hear the classic rumor in the speaker;;;, I state that it is a dual mono and that the other channel is working properly.
I take this opportunity to make you all the best wishes for a happy New Year 2013.

Zen Mod 31st December 2012 10:53 AM

pics , pretty please

vivanco 31st December 2012 10:55 AM

Quote:

Originally Posted by Zen Mod (Post 3305341)
pics , pretty please

I'm sorry dear zen, I did not understand a thing you mean, unfortunately I use a web translator

Zen Mod 31st December 2012 11:00 AM

I mean - give us pictures

plenty of them

it doesn't matter are they on Italian or English

:clown:

Backbones 31st December 2012 11:04 AM

Fotografia per favore.

vivanco 31st December 2012 11:22 AM

Quote:

Originally Posted by Zen Mod (Post 3305351)
I mean - give us pictures

plenty of them

it doesn't matter are they on Italian or English

:clown:

this is the photo that shows the short circuit between the two tracks on the pcb :

http://img560.imageshack.us/img560/3444/32791556.jpg

Uploaded with ImageShack.us

this is the correct picture of the pcb :

http://img441.imageshack.us/img441/6808/buonat.jpg

Uploaded with ImageShack.us

Zen Mod 31st December 2012 11:32 AM

Jim's Audio again .......

whatever ......

give us more pictures , and clearer , please

all I see , from these two , is info you already gave - about short circuit

vivanco 31st December 2012 11:40 AM

Quote:

Originally Posted by Zen Mod (Post 3305373)
Jim's Audio again .......

whatever ......

give us more pictures , and clearer , please

all I see , from these two , is info you already gave - about short circuit

But, as I said, the problem of the short circuit has been removed ..... I try to explain the current situation:
speakers connected to the respective output terminals of the protection circuits, signal inputs vacuum, there are no problems because the LEDs present on the protection circuits, are access and then indicate correct operation,,, tapping the XLR input, noise is heard on the speakers ........... when I connect the right channel signal, the amplifier sound properly, while just connect the left signal (on the pcb that had the problem) its its protective circuit operates by disconnecting the speaker.

I do not have more pictures, but I can assure you that now the channel is properly assembled, also as a precaution I replaced all mosfet IRFP9610 and one ZTX450 (because I had no other spare) .... but the strange thing that leaves me perplexed is the fact that if not connect the input signal everything seems to work,,, the only thing different, compared to the other channel, is the measure of the offset, in fact on the channel functioning is 20mV, while on the indicted is 80mV

Zen Mod 31st December 2012 11:44 AM

without more info no-one can help you

if you have schematic , post it , and I can mark what voltages you need to measure to give more insight in problem

vivanco 31st December 2012 11:45 AM

Quote:

Originally Posted by Zen Mod (Post 3305385)
without more info no-one can help you

if you have schematic , post it , and I can mark what voltages you need to measure to give more insight in problem

the scheme is that of the Aleph 30


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