pakko
Member
Hey everybody,
I need your help with my Pioneer SA-9900. I reworked the whole amp in the last days.
Replaced Caps and Transistor - like a lot of you here in this forum.
So, everything works fine except for one thing I don´t have a explanation for.
If the Amp runs with a source hooked up (let´s say input Tuner) and the Volume is set to zero - I still can hear the source! It´s not possible to reduce it totally. With no source hooked up you still hear a hiss/sough on both channels.
I located the problem to the control amp (AWG-031) - there the input (comes from Switch and Input boards) the at pins 10 and 13 is absolute quiet. But I do get a signal at pins 2,3,4,5 and 7 and on the other side as well on 16,18,19,20,21 (pins 6 and 17 are quiet)
What I did on this board - I changed all the caps, changed the 4 x 2SC1451 transistors and today I changed the 4 x 2SK34 as well.
By the way I replaced all 2SC1451 with 2SC1953
I say it again - everything else works fine - the amp section measures fine with Bias and DC Offset etc. - If I separate the amp, it´s clear the problem comes from the pre-amp section.
Hopefully someone has an idea how to go on.....thank you
I need your help with my Pioneer SA-9900. I reworked the whole amp in the last days.
Replaced Caps and Transistor - like a lot of you here in this forum.
So, everything works fine except for one thing I don´t have a explanation for.
If the Amp runs with a source hooked up (let´s say input Tuner) and the Volume is set to zero - I still can hear the source! It´s not possible to reduce it totally. With no source hooked up you still hear a hiss/sough on both channels.
I located the problem to the control amp (AWG-031) - there the input (comes from Switch and Input boards) the at pins 10 and 13 is absolute quiet. But I do get a signal at pins 2,3,4,5 and 7 and on the other side as well on 16,18,19,20,21 (pins 6 and 17 are quiet)
What I did on this board - I changed all the caps, changed the 4 x 2SC1451 transistors and today I changed the 4 x 2SK34 as well.
By the way I replaced all 2SC1451 with 2SC1953
I say it again - everything else works fine - the amp section measures fine with Bias and DC Offset etc. - If I separate the amp, it´s clear the problem comes from the pre-amp section.
Hopefully someone has an idea how to go on.....thank you