PSU in Onkyo TX-2000 receiver

[stex]

Its time to change PSU caps in my old Onkyo TX-2000 receiver. Old Nichicon 4700uF 40v, firs replace by 10000uF 50v Nichicon, sound is disaster. Slow, boooom bass with ok mids and slightly soft highs. Second I put 10000uF Elna for audio caps, bass is better, but still slow. With 6800uF 50v Elna for audio caps, sound is weary pleasant. Bass is tight and deep, mids is ok and treble like silk, almost like tube amp. Power amp in receiver is STK chip. If any has similar experience, pleas write. Maybe better value for caps? I also replace blow lamp for scale with blue led and its look fantastic . Sorry for my Tarzan English.

[carlmart]

Originally posted by stex
Its time to change PSU caps in my old Onkyo TX-2000 receiver. Old Nichicon 4700uF 40v, firs replace by 10000uF 50v Nichicon, sound is disaster. Slow, boooom bass with ok mids and slightly soft highs. Second I put 10000uF Elna for audio caps, bass is better, but still slow. With 6800uF 50v Elna for audio caps, sound is weary pleasant. Bass is tight and deep, mids is ok and treble like silk, almost like tube amp. Power amp in receiver is STK chip. If any has similar experience, pleas write. Maybe better value for caps?

It sounds very much like what most of us has experienced with the LM chips, particularly 3875 and 3886: smaller caps improve the sound. You should try smaller ones, perhaps not larger than 4700uF, and see what happens.

A different approach, that seems to improve both ends, might be to use a regulator. What type will depend on the transformer you have, as you may use two positive types (like LM338) if you can split the two secondaries. If not you should look for 3A to 5A negative and positive types, or use a discrete regulator.


Carlos