Marantz Model 2220 restoration

onanysunday

Listen carefully
Hello, I just picked up this old receiver. There are no lights anywhere in the front except for the red "stereo" light indicator and I cannot locate bulbs after removing the faceplate or figure out how to restore lighting, any help on getting this lit back up is appreciated.

So far I've thoroughly cleaned all the switches on the front panel which really cleaned up the audio signal quite bit and removed some static and grain in the music. It sounded very clean, crisp but also bouncy and very lively and exciting in the midrange. I also adjusted the offset voltage and got it dialed in perfectly on both channels at 7.5 mV. So far this is a great sounding receiver, All audio outputs worked when I rescued it from a thrift store last week, but now I lost audio out of the rear RCA jacks on the back but I can still hear beautiful music through the headphone jack. Going to recap this one and hope to restore its missing audio in the process. Any help or advice on this restoration is appreciated.

It really does sound amazing for its age. Its from the early 70's and is so old it uses all discrete components by necessity, no integrated circuits! How refreshing.

Marantz Model 2220 front.jpg 20180327_153418.jpg Marantz discrete.jpg
 
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I would clean all the switches again. If you start with dirty contacts and clean, sometimes you may move some crud to places where it wasn' previously a problem. Get the selector switch, volume pot and tape monitor switch as clean as possible.

In order to properly clean the switches you usually have to remove the bottom panel and clean the contacts on the back if the switch. Look to see if you knocked and wires loose there while cleaning.

You may want to build a dim bulb tester as the 2220 does not have a protection circuit and relay. If theres a short somewhere, it will most likely cook something else when powered on. A DBT will make this instantly visible while limiting the current for the few seconds you need to verify the fault.
 
I wish I could locate where the bulbs are hidden on this thing. I don't know how to access them- they would be easy to replace/ test if made visible. In terms of the audio cutting out on the rear jacks, I didn't do anything to cause any problems to happen with this except for cleaning the switches. I will try cleaning them again one more time. I noticed they lose that nice smooth greased feel after cleaning them. I suppose there's no nothing to be done about this..? They are much easier to turn now but also don't feel quite as smooth as they used to.
 
Thanks! I had repeatedly sprayed several doses of contact cleaner into the switches and pots. I could've loosened some debris. I gave it another round of cleaning, this time with Deoxit D5 for the switches and faderlube on the pots. The "smooth feel" of the switches have returned and so has my audio. There is also a much darker background level now when listening at quieter volumes. Now I will try and tackle the lighting. Thank you for the video and help so far.
 
It's not as complex as I was thinking it was. It boils down to just a couple hard to reach screws and the long backing plate has come off to expose 5 fuse lights. I had thought the electrical wires going in the back were for the dials and buttons themselves. Going to order some led replacements and recap the boards. Probably a mix of Chemi-Cons in the power section and Elna Silmic II most everywhere else. It originally came with a mix of chemi-cons and elnas inside, and as it turns out, these are my favorite electrolytics to use for audio anyway.

Does anyone know whether there could be any improvement in sound quality realized by replacing some selected ceramic caps with films or other replacements with a tighter tolerance than some of the 10% oem "K" grade ceramics it has on it? Part of me is just curious to know whether any different, or perhaps modern capacitor materials could really shine here..
 

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It's not as complex as I was thinking it was. It boils down to just a couple hard to reach screws and the long backing plate has come off to expose 5 fuse lights. I had thought the electrical wires going in the back were for the dials and buttons themselves. Going to order some led replacements and recap the boards. Probably a mix of Chemi-Cons in the power section and Elna Silmic II most everywhere else. It originally came with a mix of chemi-cons and elnas inside, and as it turns out, these are my favorite electrolytics to use for audio anyway.

Does anyone know whether there could be any improvement in sound quality realized by replacing some selected ceramic caps with films or other replacements with a tighter tolerance than some of the 10% oem "K" grade ceramics it has on it? Part of me is just curious to know whether any different, or perhaps modern capacitor materials could really shine here..
Leave the ceramics alone, where they are used is normally non-critical areas as ac/dc decoupling, not audio. Get rid of the tants in there (I'm pretty sure there's some).
Threads that may help capacitor selection.
http://audiokarma.org/forums/index.php?threads/marantz-2220-recap-attempt.497856/
http://audiokarma.org/forums/index.php?threads/new-restore-project-marantz-2220-the-sequel.752048/
 
Could not locate tantalums after finding the parts list for this model. Only ceramic, film, and electrolytics are listed on the boards. I'll keep it simple and just do the electrolytics. I've also wanted to give the Elna Tonerex a try. I read some transistors can be troublesome on the 2220 and should just be replaced while in there.
 
Just recapped the FM board last night as it was one of the easier boards to access. Next going to work on the front end board, but the remaining boards appear difficult to access to replace the caps because there are so many tight-fitting wires soldered directly into the boards, leaving little room to work.
 
If anyone has ever worked on this model before, do you know if the rest of the boards need to have all their wires unsoldered in order to access them from both sides for cap replacement?

Interestingly, all the elnas I pulled had higher than rated capacitance, although their ESR was higher than their replacements. Usually, capacitance ratings diminish as the caps age. Although, the larger power caps are all measuring low.
 
Capacitance almost always increases with age.

You may be able to unolder the pins and remove the wires without having to unwrap them. I see people often cut the wires and just solder to the top of the pins but I would advise against this. Those wire wraps are always filthy and will contaminate your joints. Keep it neat and tidy!
 
I am definitely going to try your method of unsoldering the wrapped wire ends from the posts just enough to slide them off but not unravel them. In terms of capacitance increasing with time, I've seen it both ways, but my experience is that I've definitely come across more diminished capacitor values than not throughout all my recap projects. It could be because perhaps many of these caps were below rated capacitance to begin with. Of course, esr goes up in every instance, especially when compared to the lower esr and impedance of modernly available electrolytics.

I test each one for capacitance and esr before I decide to keep them or throw them away and replace them with new ones which I measure to be within 4% rated tolerance. To be fair, it could also be the material I work with which is mainly the passive components of 80's Japanese CD players of which I've recapped several dozen.

The Marantz is a different beast than what I am used to working on- much older. Constructed better, heavier, more substantial using discrete components. No cheap plastic, molex connectors or ribbon cables here, just some good old unsoldering of wires. Kind of refreshing in a modern world where everything is comprised of integrated circuits and unserviceable micro technology.
 
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I am definitely going to try your method of unsoldering the wrapped wire ends from the posts just enough to slide them off but not unravel them.....

Not sure if I've understood you correctly - but, if you mean wire wrap connections, where single (solid core) wires are wrapped around vertical pcb mounted posts, then you would be better advised to unsolder the complete pcb mounted post + wire from the pcb, and leave the actual wire wrap connections well alone.

Wire wraps are not soldered connections, at least not when they leave the factory, and they are virtually impossible to replicate without the use of the correct wire wrap tools. Attempting to loosen & slide them off the post will just destroy what is probably still a very good connection.
 
Not sure if I've understood you correctly - but, if you mean wire wrap connections, where single (solid core) wires are wrapped around vertical pcb mounted posts, then you would be better advised to unsolder the complete pcb mounted post + wire from the pcb, and leave the actual wire wrap connections well alone.

Wire wraps are not soldered connections, at least not when they leave the factory, and they are virtually impossible to replicate without the use of the correct wire wrap tools. Attempting to loosen & slide them off the post will just destroy what is probably still a very good connection.
Yep.
 
These terminations are a trick to deal with. The posts change orientation and twist inside the pcb hole like little spades, making them very difficult to remove even after the solder has been removed. I'm not sure if they're permaneny clamped into the PCB board. So far I've left the original wire wrap as I don't think I could do a better job putting it together. Once I get these wires out of the way, I can have access to another of the boards, this time the stereo decoding board.
 

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These wires are multi-stranded, but unsoldered wire isn't as malleable to work with and re-solder as fresh. I suppose I could just cut the wires back and expose fresh wire, though at the expense of shortening up the length of the wires a bit. I don't think there's a science behind tightening multi-stranded wires on posts as they all seem handmade. I could be wrong, although I know exactly what you are referring to with the coiled, solid core wires that wrap around perfectly.
 
Here is a complete parts list for electrolytics on the main power amp/supply boards and also the fm/am front end board which you can use to order replacement electrolytics. I personally verified all of these. Possibly more to come. One board at a time. I just finished the first which was the FM IF amp board.

I decided to keep all the ceramics in place as apparently there was something special going on with them in terms of how the fm was implemented in a particular way so I left them alone. There are several electrolytics up front and then just a sea of ceramics in back. Used the Elna Silmic II and Nichicon FG I had on hand.

*note the last two 47uf 50V caps on power amp section are from the power supply board and written for ordering purposes. Hardest to read (1) 220uf 6.3V (1) 0.47uf 50V and (1) 100uf 50V

marcap.jpg marcap2.jpg
 
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