Now I get -24v and +24 to the pcb but no sound.. gah... i wonder how i bridge the input of rca?
Somewhere in the input stage of the amplifier there are connections for +IN and -IN. So connect the RCA inner and outer conductors to those, and to nothing else.
I am not familiar with that amplifier but from a schematic I found:
http://www.diyaudio.com/forums/pass-labs/111197-aleph-j-schematic.html#post1341101
it looks like you should NOT connect the RCA jacks to the chassis, or to ground, or to anything except the +IN and -IN points in the circuit (since the circuit has a differential input and -IN is separated from ground). So if that's true then you need isolated (insulated) jacks.
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first off. do the amp heat up?
i think a little bit... i get only 0.05vdc across r7?
Somewhere in the input stage of the amplifier there are connections for +IN and -IN. So connect the RCA inner and outer conductors to those, and to nothing else.
I am not familiar with that amplifier but from a schematic I found:
http://www.diyaudio.com/forums/pass-labs/111197-aleph-j-schematic.html#post1341101
it looks like you should NOT connect the RCA jacks to the chassis, or to ground, or to anything except the +IN and -IN points in the circuit (since the circuit has a differential input and -IN is separated from ground). So if that's true then you need isolated (insulated) jacks.
Thanks -- I will try this too! All I get a is a little thump when I turn it on
how about R8?
and R16-18?
R8 - 8.44vdc
Z1 - 9.01
R16 - .36vdc
R18 - 0 across r18 and a pop came thru the speaker
R8 - 8.44vdc
Z1 - 9.01
R16 - .36vdc
R18 - 0 across r18 and a pop came thru the speaker
are you sure you dont have a short on Q7 or 8?
and du you have -24V at the PSU with the amp on?
R8 - 8.44vdc
Z1 - 9.01
R16 - .36vdc
R18 - 0 across r18 and a pop came thru the speaker
desolder R10 and R12 and pull them out
check again voltages at R7 and R8 , write them here
ground both inputs while doing testing like these
@AudioSan
yeah
chasing bloody schm
doing someone other's HW , as usual
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hehe🙂 you have too many schematics😀
i don't see any short between pins of those... yes i have both rails at pcb DC input.
and you are sure R7 is 1Kohm (1000ohm)?
Audio, Yup and yes.
Zen... I will try that but i have some unmounting to do...it will wait for later if i can't get it.
Zen... I will try that but i have some unmounting to do...it will wait for later if i can't get it.
Audio, Yup and yes.
Zen... I will try that but i have some unmounting to do...it will wait for later if i can't get it.
did you chek R19? is that one 0V also?
it is somthing wrong on your -24V somewhere. +24V seems okei.I have .04v across EC of ztx450 Q3 and 0v across R19
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