hey everyone,
i was wondering if anyone had schematics for a RA-820BX4 Rotel Amp. just picked it up super cheap - i want to do some upgrades on it. any help would be awesome.
i was wondering if anyone had schematics for a RA-820BX4 Rotel Amp. just picked it up super cheap - i want to do some upgrades on it. any help would be awesome.

Holy cow, i used to own one of those! I bought it new bacy in the mid 90's....I sold it on audiogon i think....maybe u ended up with it?
Hey there, I bought this one from a guy I used to work with at a stereo shop. He bought it new and was sitting in his garage for the past few years. However, its no longer an integrated - we have modified it to a straight power amp. We also installed a pre-out off the volume control of my RA-931AX Integrated. Just have to beef it up now. It sounded a quite thin and narrow compared to my modified 931. Get little amps though.😎
You could probably make some decent mods in that thing also. When I owned mine i didnt know much about mods but now....u could up the caps with blackgates, the resistors with vishay's, and swap out the opamps. I would even swap out the volume pot with a stepped one since it is not a remote motorizd one in there!
Yeah - I plan on adding a bunch of caps, i've changed the opamp already but i'm not using the volume control on it. I have the pre-out signal coming off the volume control of my RA-931AX. I also have a new power cord for it, should be have it next week Fri. I also plan on changing the caps in the feedback section to silver mica caps. Basically I have to repeat all the mods I did on my 931. Caps, power cord, opamps, new recdifier, new stepped current bias pots, decoupled the opamp. and adjusted the current bias to 6mV. I think stock is 2.5mV. Any other suggestions would be cool!!!
😎

😎
What kind of cd player you using with this? I use a modded rotel rcd-971 with my current integrated (a Rotel RA-1060),
and i use a Meridian 508.20 with my Levinson 38s Pre/333 power combo.
and i use a Meridian 508.20 with my Levinson 38s Pre/333 power combo.
Hey! I'm using a modded RCD930AX. It has an AudioQuest Power Cable, browned breaded bridge on the transport and chasis, OPA2134 Opamp, decoupled, new caps on the main board, and an emi filter. Compared it to a new RCD1072 - mine sounds more open, detailed and smoother. The sound stage is very impressive. 

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