I’m restoring my M3s and next up will be repairs and upgrades to the MK 121-2A interfaces. I’ve seen lots of references to components to replace and modify but I haven’t found any specifics or schematics. What should I be looking to replace and how? If anyone has published a good reference please share it!
Also wondering what I should expect from the mods. I’m having trouble developing full volume, I’ve been blaming the amp for being underpowered (H/K Citation Sixteen, 250 wpc @4ohms) but maybe it’s the interface?
Also wondering what I should expect from the mods. I’m having trouble developing full volume, I’ve been blaming the amp for being underpowered (H/K Citation Sixteen, 250 wpc @4ohms) but maybe it’s the interface?
Replace the High voltage diodes, high voltage caps ( the ceramic ones) and the 500 Meg resistor. The speakers may work but are low in efficiency because of worn out high voltage components.
Also perform the C mod with polypropylene capacitors.
Also perform the C mod with polypropylene capacitors.
Good advice, but the 500 Mohm resistor rarely goes bad. Save your money on that part. Bias supply parts (diodes and capacitors) can go bad and will reduce the sensitivity of the speaker, which means low volume for a given input.
The C-Mod is also recommended but will not solve any of your complaints so far. The C-Mod is an incremental improvement in sound quality: don't bother with it until you are otherwise satisfied with the speakers' performance.
The C-Mod is also recommended but will not solve any of your complaints so far. The C-Mod is an incremental improvement in sound quality: don't bother with it until you are otherwise satisfied with the speakers' performance.
