When I was 16 I found out about the Yamaha CR3020, an absolutely massive, $1500, 160W per channel, 78lb, ebony veneered, 25 inch wide beast of a stereo receiver that was released in 1978. And at 28 years old, I've finally managed to buy one. Not only is that incredibly exciting in and of itself, but I also have the skills to service it and this one was having some issues with the sound cutting out at low volumes. That is typically caused by a dirty Pre out/Main in coupling switch on the back of the receiver but can also be cause by dirty speaker relays. There are 3 speaker relays in this receiver, one for each set of speakers! I also checked for a known issue where the pre driver transistors on the driver boards can come loose and destroy the relays or power supply.
This unit is very clean and I purchased it from the original owner after taking a roadtrip down to Bend, OR in November of 2023. It was super fun to spend time with the original owner and hear about all of his memories using it. I hope that I never have to sell this because to me, it's the pinnacle of receivers that I could want from the 70's.
I also recently acquired a second CR 3020 that I will be completely restoring and listing for sale later this year. If you are interested in it, please send me an email. I may need to reveneer it so we could work together on making it a unit that is custom to your tastes. [email protected]
Chapters:
00:00 Intro
00:19 Specs, Manufacturing, & Background info
05:25 Background on my CR 3020
06:19 Disassembly & Fun Design Elements + Build Quality
07:48 Removing the Driver Cards, Relay board, and Coupling Switch
09:06 Cleaning The Pre out/Main in Coupling Switch
10:15 Cleaning the Speaker Relays
13:58 Fixing a Major Flaw in the Design
15:02 Reinstalling the bottom cover and driver boards
15:23 Testing on Dim Bulb (Use 150 to 200 Watt bulbs)
17:00 Adjusting Bias (Idling Current)
17:26 Adjusting DC Offset (Mid Point Voltage)
17:51 Final Testing
18:15 Loud Listening Test
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My name is Matt. I live in Washington State and create content around vintage stereos and other audio equipment. I approach the hobby from a technical standpoint and am learning about circuit design and repairing and calibrating amps, turntables, speakers, etc. I really appreciate a good aesthetic and the vintage stuff fits my taste.
I'm also offering repair services on a limited basis. You can find my email address as well as info regarding services by going to my channel page (click the name next to my round profile photo) and locating the text bubble below the channel name.
Instagram: @Shuksanaudio
Tik Tok: @Thedealydeal