A few days ago i changed the coupling caps and the input electrolytics in my Jungson JA88D-09. I changed all of them to 1uF Jantzen silver z-cap. The problem is when amp has been on for a few hours it's getting hot and it never did that before. Another problem is that the sound is louder in the left channel than in the right. Can this be because the idle current and the dc offset is wrong or maybe some thing else?
The schematic can be found here: Duro
The schematic can be found here: Duro
Reducing the value from 10u to 1u should have the opposite effect. Maybe you have a faulty capacitor?
You state you changed "all of them". There are only two!
You state you changed "all of them". There are only two!
Try putting the 4µ7s back. The new caps might cause some sort of unfortunate oscillation. (I assume you don't have a scope?) Also, if one channel is now louder there may be a bad solder joint somewhere, so double-check your work (look for unwanted connections as well).
That amp is never going to have super low distortion anyway, what with the entire output stage being outside the feedback loop. Should be quite well-behaved up to ~5 W into 8 ohms though, even if it has to be said that a GNFB concept could perform even better given that kind of idle current.
That amp is never going to have super low distortion anyway, what with the entire output stage being outside the feedback loop. Should be quite well-behaved up to ~5 W into 8 ohms though, even if it has to be said that a GNFB concept could perform even better given that kind of idle current.
Last edited:
The 4u7 capacitors are coupling the input stage (which is current feedback based) to the driver stage. If you have put physically large caps in with long leads, it is quite likely the added lead inductance is causing the output stage to oscillate. Put the originals back.
- Status
- Not open for further replies.