Hi all-- longtime reader of AK (especially the Pioneer forums) but first time poster. This site has taught me most of what I know about audio, so a big thank you to everyone here.
So, I managed to get myself an A-91D, "working," but not entirely. The amp sounds and looks great, which is why I want to get the thing working the way it should be. It has two issues. First, in direct mode it sometimes only gives sound from one channel. To deal with that I'm planning to start by replacing the direct mode relay along with all of the similar relays that are known to cause problems (all Omron G2VN-237C-PA), unless someone has an alternative suggestion.
The second issue is with the digital inputs. On all of them, sound comes in and out in both channels and occasionally distorts. One minute it's great, the next it's almost completely gone. Tried cleaning everything-no improvement.
Now for the really bad part. After checking the connections within the boards, I went to test the digital inputs again. But when I powered up the unit, saw a sudden plume of smoke. Turns out it was one of the ICs on the DAC 2 board. Don't know how it happened but was probably carelessness on my part.
Fortunately, everything else survived intact. But now I have an IC split clean in half (PD0012A) and a trace that needs fixing, along with the original sound problem. So my question is--does anyone have experience with the digital inputs /DAC assemblies on these units or a guess of what could be causing this problem? I'll replace the IC, along with the capacitors directly linked to it, but should I also be thinking about recapping the entire DAC assemblies?
Thanks!
So, I managed to get myself an A-91D, "working," but not entirely. The amp sounds and looks great, which is why I want to get the thing working the way it should be. It has two issues. First, in direct mode it sometimes only gives sound from one channel. To deal with that I'm planning to start by replacing the direct mode relay along with all of the similar relays that are known to cause problems (all Omron G2VN-237C-PA), unless someone has an alternative suggestion.
The second issue is with the digital inputs. On all of them, sound comes in and out in both channels and occasionally distorts. One minute it's great, the next it's almost completely gone. Tried cleaning everything-no improvement.
Now for the really bad part. After checking the connections within the boards, I went to test the digital inputs again. But when I powered up the unit, saw a sudden plume of smoke. Turns out it was one of the ICs on the DAC 2 board. Don't know how it happened but was probably carelessness on my part.
Fortunately, everything else survived intact. But now I have an IC split clean in half (PD0012A) and a trace that needs fixing, along with the original sound problem. So my question is--does anyone have experience with the digital inputs /DAC assemblies on these units or a guess of what could be causing this problem? I'll replace the IC, along with the capacitors directly linked to it, but should I also be thinking about recapping the entire DAC assemblies?
Thanks!