A new version of our Marantz 2270 restoration can be view by clicking here.

Recently I was sent a pair of Marantz 2270 stereo receivers for restoration work. The receivers were close in serial numbers and in good shape. They were never serviced and both seemed to “work”. After some output testing before service it was found they both lacked a bit of power which was to be expected of a stereo of this vintage.

First, replace the electrolytics and speaker protection relay on the power supply / protection board.

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Next it’s on to the phono preamp. New electrolytics, several film caps, and replace some notoriously noisy transistors.

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On to the tone amp section. Here electrolytics were replaced and several low capacitance electrolytics were replaced with Panasonic film caps.

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Supply filter caps replaced with Panasonic 10000uf/80v. Film bypass caps added.

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New electrolytics on amp boards.

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Faceplate removed and new vellum paper installed with new dial and meter lamps.

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Receivers were biased and ran for many hours before rechecking bias and output tested. Both receivers are putting out well over the modest 70wpc factory spec.

17 Responses

  1. I have a 2270 that I bought new many years ago. It has worked beautifully, until tonight. I was playing some Daryl Hall at moderate volume and all of a sudden, the audio went dead. I checked controls and switches to no avail. Powered it off, then back on, and didn’t hear the familiar sound of the relay. Should I start by replacing the relay, or should I just go ahead with the rebuild steps you’ve mentioned above?

    Would you be willing to supply a list of the part numbers and specs for the relay/caps/etc. that you recommend replacing in a rebuild, along with some tips for the process?

    I’d love to keep this thing humming along, if possible.

    Thank you.
    Eben Fowler

    1. Hi Eben,

      Not a nice way for your 2270 to treat Daryl…lol. Sounds like the protection circuit kicked in and since it will not reset when you powered off and on the amp you might have a blown component. It is probably not the relay unfortunately. Do you have a digital multimeter that you are confident in using? If so we can do a few simple tests to get started diagnosing the problem. Also open the case and get a good look at the boards. Look for bulging capacitors, burnt resistors, burnt boards.

      If you feel you can do some of the rebuilding of your 2270 send me an email and I can give you details on ordering parts and complete kits. Always here to help you along the way. mike@hudsonvalleyhifi.com

  2. Hi Mike,

    I live in Brazil and have a couple of Marantz receivers – a 2275 and a 4270. They both have run beautifully for years. But for the last week, the the 4270 has been acting strangely. It started to turn off, and then after a few minutes would turn on again. But last night it turned off and now it won’t turn on. The speaker relay switch is affixed to the inside of the back panel. I have no idea how to remove it for examination
    My situation is complicated by the fact that in this country there is no ready supply (even by mail) of parts. International mail is very expensive and unreliable.
    I would much appreciate any advice. Kind regards.

    1. Bill, there are amplifier alignment adjustments that may fix your problem or give you an idea as to what is wrong. Do you have the service manual for the receiver? If not contact me via email and I can send it to you. Most amplifier alignments only require a multi-meter.

  3. Hello Mike,

    Last night I broke the signal moving cable of the AM/FM tuner of my Marantz 2270. Any idea where I can buy this cable?

    Thank you for your help
    Benjamin

  4. Hi Mike,

    My 2270 will not shut off. I have to unplug it after usage. I took the cover off and sprayed deoxit into the power button shaft I guess you would call it, and manipulated the switch a hundred times or so, no dice. Any suggestions would be greatly appreciated. Happy Holidays!!!

    1. Hi Alex, Happy Holidays! Sounds like you unfortunately have a broken power switch. When you undepress the power button the contacts carrying the AC current pull away from each other. If the switch is broken they will not pull apart and the unit will stay on. There is no harm in using a power surge protector to turn the receiver on and off. I always recommend turning off your source, volume down, and turn off speaker selection before powering down any piece of equipment. There are switches out there from several sources. You can check eBay or shoot me an email and I can give you a few other places. Good luck!

  5. I have a Marantz 2270. The power switch will not stay on, push it in but comes right back out. I need a replacement switch. I have been searching on line and can’t seem to find where to get a replacement. Do you have any ideas?
    I live in Virginia.

    I did find this web site though 🙂

    Thanks

    1. Hi Harry,

      Send Dave an email at dgwojo.com I believe he has some power switches. Mention Mike from Hudson Valley HiFi sent ya!

      -Mike

      1. Hey Mike,

        Can you send me an email regarding a full restoration of my Marantz 2270. Thanks in advance. I would consider sending it to Long Island.

        Alex Platt
        Massachusetts

  6. I have a 2240 with an intermittent left chanel . It plays. Ok for a while and then the sound in one channel disapears until the receiver is turned off and on agin. Any suggestions on how i can fix this ?

    1. Hi there, few things to try first. Pull the preamp-amp jumpers on the rear of the receiver and spray with deoxit inserting several time. Also, try a set of RCA interconnects instead of the jumpers.

      Secondly, clean the control potentiometers with Caig Deoxit. This involves removing the bottom cover and spraying up into the pots body while exercising the control.

      If these do not work it is possible you have a failing signal transistor that is leaking when the unit heats up.

      Let me know if there is any other things I can help with. mike@hudsonvalleyhifi.com

      Good luck!

      Mike

  7. Hi I have a 2270 and get a hum on the phono inputs only. Turntable is connected to ground on the 2270. I get the hum through headphones too. The phono channel is hum free without a TT plugged in. I’ve tried a different TT same deal… I get the hum at 9 oclock and up on the volume.

    1. Hi Steve, it sounds like there is an issue with the phono stage. The 2SC458 transistors on the board are prone to failure alone with the capacitors on the board. With out seeing the unit I cannot diagnose it but failure in the phono preamp is common. Let me know if we can assist you further. mike@hudsonvalleyhifi.com

  8. Hi there –
    I have a Marantz 2270 which has never had any problems until recently. I have the power switch issue that others have listed above (I just use a power strip), but more importantly, I have a very strange new issue:
    I have a dual cassette deck connected to the receiver (much newer and has polarized plug), and for some reason when it is plugged in on the same power strip (or even the same outlet), the tuner on the receiver no longer works!
    I also notice that when the cassette deck is plugged in, the overall volume of the receiver is much lower (such as when listening to turntable), and if I unplug the cassette player from power strip but hold the plug near the outlet, I hear static in the receiver.
    I’ve looked all over the internet for answers but not able to get anywhere. You have been really helpful with others’ weird questions, so I would appreciate any help.
    Thanks
    Matt

    1. Hi Matt, it sounds like a ground loop issue. Try hooking the tape deck to a different outlet and it will likely go away. -Mike

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