CR-2020 Full Restoration

Wertz

AK Subscriber
Subscriber
Growing up, my dad had all vintage Yamaha gear. My first "tinkering" at the age of 3-4 came with moving all the toggle switches on his CA-810 amp, and spinning the dial on his CT-610 II. Awhile back I restored that system for him, and have been wanting a new audio project ever since. I've had a couple friends push the Pioneer SX series on me. Just restored a SX-880 last week and loved it. However, I keep coming back to wanting a 70's Yamaha setup. I love the looks and the memories it brings back.

I decided to go big and bought a burnt up CR-2020 on eBay this past weekend. I'll post picts once it arrives and detail progress on restoration. I plan to redo the veneer and repaint the top vent in addition to the service bulletins and a general recap. Look for updates in the coming weeks! Should get the unit in 10 business days or so.

Auction: http://www.ebay.com/itm/291039638371?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Seller's picts attached
 

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Thank you for the support! I'll be sure to take some good progress shots and post my Mouser part lists (once I know I've ordered stuff that works). :)
 
Thank you Avionic. I didn't not use the company laser printer for the service bulletins, service manual, and owners manual today. :D
 
Big Yamaha Natural Sound fan here. I have a CA-810 I've had since College (brand new then) and I've owned/still own a few CR's and CA's. I love them.

I'd definitely dive in and enjoy that rebuild. Please keep us posted on how it's going, and we want to see PICS along the WAY! FUN!

Enjoy!

Billy
 
Should get here by 12/31, if FedEx is correct. Also have some new lamps on the way from Dwojo, and a Mouser shopping cart ready to go!
 
Unit arrival

The 2020 showed up in the mail today! As I guessed from the sellers pictures, the top grill is heat damaged and the case needs minor refinishing. The only surprise was the loudness knob being bent and falling off. Hopefully some careful pliers work can get that realigned without replacing the entire switch. More pictures and progress to follow!
 

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Already found why the seller had a channel out. I was afraid it was a burned up output transistor. Turns out a few wires chose to disconnect themselves from their solder joints. Also, the input is stuck on FM. Does not want to switch to any others. I'm going to start with the service mods and power supply rebuild. Then work my way onto the other fun problems. :)
 

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Would love to see a list of parts used. I'm planning on doing a re-cap on my 2020 soon.

Can do! I will post my mouser shopping cart soon. I'm still adding parts to it though as I go along. I'll make a note of which parts are for which boards. I spent a few hours comparing data sheets of various caps. I used to prefer Nichicon UPW for general caps and UKL for low leakage. However, I'm finding that Panasonic FM and FC generally have the best balance of high ripple current, low leakage, low impedance, and high temp tolerance.
 
Dismantled the entire front end. Used Turtle Wax aluminum polish on all knobs and switches. Deoxidized button/ switch contacts and jacks. Cleaned meter covers and tuner glass. Realigned loudness control shaft and reglued knob to plastic backing. Repaired multiple broken solder joints for wires. Removed main circuit, cap, and relay boards in preparation for service mods and recap. Making progress! Still building a complete mouser shopping cart; will hopefully be able to order parts tonight. Front faceplate is in surprisingly good shape, with very minor scratches. All lettering is perfect. Tuning knob is fairly scratched up, so may be ordering a replacement.
 

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Got all parts ordered last night for service bulletin work and capacitor replacement. Going to start off redoing cap board, relay board, and both main circuit boards. When I get bored again in a week I will likely redo the rest of the caps. :)

Already knew I wanted to give Panasonic FM and FC a try. I'm populating the cap board and most of the relay board with those. I also ran across a new release at Mouser, the Panasonic FR, which appears to be a newer version of the FM. I ordered a few of those too. For anything in the direct audio signal path I decided to go with Elna Silmic II, given their excellent specs and many positive reviews.

Anyone used audio grade caps on power boards with success?
I have heard of people redoing entire receivers using Elna Silmic IIs and claiming it was worth the money. I'm fairly skeptical of redoing the hot, crowded relay board in caps rated below 105C. However, I see a couple of 85C caps on those boards from yamaha that have held up thus far. The Silmic IIs have high enough ripple current and low enough impedance to be competitive with my former go-to Nichicon UPW's. Plus they have significantly less leakage as compared to the Nichicon power supply line. So in theory, they should work just fine. Where available, I ordered several duplicates in Silmics to interchange with Panasonics later on if I ever feel like it. I'll post the completed list of parts once they come in and test good.

Any thoughts from other Yamaha restorations on what caps you prefer in power vs audio boards?
 
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I tried Elna Silmic II on the power boards but I lost almost all of the bass. Started with overwhelming boomy bass but then it just faded away. The treble and the midrange was quite good but it was a bit bright. I later changed to Panasonic FC and now I got a nice punchy bass with a a bit forward midrange and warm highs.
I have used FC everywhere except signal path where i used Silmics and it sure sounds nice.

I have also tried Silmics in other amplifiers but I only like them in the signal path. I have not yet tested them against UPWs but I do have a Pioneer amp where i will do some experiments.
 
I have also tried Silmics in other amplifiers but I only like them in the signal path.

Thank you for the quick feedback! My first instinct was to go with the fm/fc series for general ps and relay board caps. They seem to be the best balance of everything. The extra/ experimental Silmics I ordered will certainly find a home somewhere.

In my last restoration, I used Nichicon UPW and UKL. The bass was tight and mids and highs were clear. However, on more sensitive speakers, such as Klipsch, there would be a slightly audible hiss on the output that was not present before recap. I realize many things can cause this, but reading up on UPW caps confirmed they may be the culprit. I'm excited to hear how the f-series sounds paired with Elna in the audio path.
 
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