Received this vintage Marantz 2270 receiver to track down the cause of distortion in one channel when playing. There was a combination of issues with the receiver and since it is in very good condition restoration work was requested to get the unit back up to original operating specs. The 2270 is a very nice piece of vintage Marantz with an exceptional phono section which once restored sounds very nice. Lastly the receiver’s lighting was converted to LED which I am please to say I have now found a LED kit that I really like. Along with a thicker vellum diffuser the kit is not overly bright and closely resembles the original lighting but without all the extra heat and short life of the incandescent bulbs. I really like the original blue look of the dial and tuning meters which over years of burning the diffuser paper the dials tend to look green. Here are some pictures of the work.

First up was the power supply. New capacitors, and speaker protection relay.

2270 power supply before2270 power supply after

Next it was on to the preamp or “tone” board in the service manual. To gain access to this board it is easy to remove the faceplate and tone control board. New to this restoration but I really like them is the small electrolytics in the signal path I replaced with high quality Wima stacked film caps. In listening to the receiver after I am starting to really like the upgrade.

2270 preamp before2270 preamp after

 

On to my favorite part of any 2270, the phono stage. This board gets a few upgrades in addition to caps I also replaced the 2sc458 transistors with KSC1845 since they are notorious for becoming noisy. Also, you can see the little ceramic diodes were replaced with high quality silicone diodes.

2270 phono section before2270 phono section after

On to the amp boards. These are a bit labor intensive to remove since I remove the output transistors from their heatsinks. This gives me access to the boards to replace the tantalum capacitors, two electrolytics and in this case I changed the input differential pair since the amp had an unstable offset. After working on the board the outputs were cleaned and regreased with non-conductive thermal paste before being reinstalled. The bias and offset adjustment trimmers were cleaned and checked to see if replacement was necessary. Unfortunately, I did not take a before shot.

2270 amp board

 

The large chassis mounted filter caps were replace and upgraded to 10000uf caps. Also, bypass film caps were added.

2270 filter caps before2270 filter caps after

All controls were flushed and lubricated. The push switches on these get especially dirty and cause havoc. Next it was on to the lighting. Here was the unit before, obviously no face plate.

20140612_173117

Two of the dial lamps were out, along with the stereo lamp, and the tape indication lamp. It was hard to get a good picture of the finished product since I think the LEDs mess with the camera and look brighter then they actually are. But here she is…

2270 LED lighting

In a dark room this receiver looks incredible and sounds even better. For this work I used Panasonic FC series high temp capacitors for the electrolytics. Panasonic THA series for the filter caps. Panasonic ECQ stacked film along with the Wima stacked film caps. The bias holds very well and offset is within 3mv of 0. Hope you enjoyed the write up and any question shoot me an email mike@hudsonvalleyhifi.com

7 Responses

  1. Mike,

    Looks great ! I have a 2270 in great shape, but would like to have it “upgraded” as was this one. Can you email me a quote? Thanks in advance.

    Alex

  2. Hi:
    I have a working 2270 but would like to have it restored as close to original specs as possible w/ LED lamps. Can you please send a ballpark quote for such work?
    Also, where is your physical location. I am in SC but get up to the Hudson Valley a coupel of times/year.

  3. Please send me a quote on how much it would run to have my 2270 restored like peter D’s. Phone stage currently works but sounds dark and lousy. FM and other inputs sound great. Sound cuts out occacionally and have to move the input selector back and forth a few times to fix it.

  4. I have a 2270 that works great. The lights are out and the pots and switches are noisy. Also, the FM tuner section is awful.
    Would appreciate a quote to fix these items. I’m leery of replacing power output components because it sounds so good and don’t want to do anything that might alter the sound quality. Thanks.

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