BSS DPR-402 Service Manual
- Thread starter frank_que
- Start date
Help Support GroupDIY Audio Forum:
Have you tried contacting BSS? (If they are still around) I bought a replacement switch from them several years ago and they were very accommodating.
pucho812
Well-known member
they are part of the harman family these days.
Yeah, maybe it has been more than a few years! They may still offer document support though.pucho812 said:
scott2000
Well-known member
frank_que said:Still no answer from BSS support...
Does anyone know how to calibrate "-10" and "-20" trimmers on VCA board? :
Maybe if you post a link to the schematic and point to where the trimmers are at, they may be able to decode what needs to be done????
Which version of VCA card do you have, the one with 13700's or that with 2150's?frank_que said:
Does anyone know how to calibrate "-10" and "-20" trimmers on VCA board? :
Now the schemo doesn't say which trimmer is what. You can tell.
Hello,
here the schematic: https://elektrotanya.com/bss_dpr402_sch.pdf/download.html
The VCA use THAT2150A (on right side of the last page of schematic) and I've replaced them with the 2181A.
I've removed R5, R7, replaced R11, R2 with 5,1K, R10, R3 with 680K, C2 with 22pf on both VCA boards.
I've also changed the op amp TL072 with a LM4562.
Trimmer PS1 sets THD, PS2 -10 and PS3 -20.
I've also made the same MOD to DPR-422, I don't have schematic of it, but the VCA circuit is identical, instead of a That 2150, there was a 2155.
Now I need to calibrate properly -10 and -20 trimmers.
here the schematic: https://elektrotanya.com/bss_dpr402_sch.pdf/download.html
The VCA use THAT2150A (on right side of the last page of schematic) and I've replaced them with the 2181A.
I've removed R5, R7, replaced R11, R2 with 5,1K, R10, R3 with 680K, C2 with 22pf on both VCA boards.
I've also changed the op amp TL072 with a LM4562.
Trimmer PS1 sets THD, PS2 -10 and PS3 -20.
I've also made the same MOD to DPR-422, I don't have schematic of it, but the VCA circuit is identical, instead of a That 2150, there was a 2155.
Now I need to calibrate properly -10 and -20 trimmers.
Well, the schemo is already in our Technical documentsfrank_que said:
https://groupdiy.com/index.php?topic=49437.msg645964#msg645964
