Sony receiver - ST-SB920 - Improvements?

[cyteen]

I've recently picked one of these up as an ebay bargain and am very pleased with it as far as detail goes but it does sound a little thin and the bass is lacking even with a good signal.

I was wondering if upgrading the opamp from the JRC 45580 to an OPA2604 or AD843 and generally uprating the capacitors in the power supply/amplifier sections to panasonic FC 50% or so larger than the existing itemswould go some way to fix these shortcomings.

Sony have used a combination of standard and nichicon VR or VR1. Should I just concentrate on replacing the items thought more important by the designers?

If anyone could take a look at the schematic and suggest some first steps to improving things I'd be greatful.

Sony ST-SB920 Manual

[Triode]

Hi, i know this is an old topic but i wonder if you made any mods to the ST-SB820 tuner? Mine sounds a little bit thin also. I would suggest to replace the coupling caps in the audio stage by a somewhat greater value, and replace the opamp by the OPA2604. And replace the muting transistors by a solid-state relais.