Tuesday, January 31, 2012

Marantz 1122DC Console Stereo Amplifier

Marantz 1122DC 61WPC restored

61 watts of class AB, DC power. Need I say more? What a beautiful amplifier with it's classic Marantz symmetrical design, beautiful warm sound that can be expected from the 1xxx series of stereo console amplifiers and more than enough inputs for all of your devices, this is all you needed. This wonderful example was brought in by a client who had intermittent and then no sound coming from it at all.



When this Marantz first came to me, it was showing signs of age. The faceplate was in much better condition than some I had seen but it was longing a nice metal clean and polish.







Upon opening it up, besides a little bit of dust one of the major problems was apparent. Can you see it?

Think Where's Wally for electronic components ;)



No? Well it was a literally blown capacitor sitting on the power board. It had actually blown it's top off!



Apart from this most of the amplifier was in fairly good condition. There were a few more buldging capacitors that needed replacement, I opted to replace all electrolytic capacitors with my capacitors of choice, the Panasonic TS-HA and AM series. The main amplifier board was easy enough to get out, thank god there were actual plugs and connectors for the most part. All capacitors were replaced and the whole board got a good cleaning. PM700 Power Amplifier board Before:



After:



Getting to the equaliser board was not so simple. It required a full removal of the faceplate, and then removing the front assembly to get to it. Not to worry, I needed the faceplate off anyway.





But if you thought that was bad, getting to the input selector required almost completely disassembling everything!

Caution: Audio lovers may find the following images disturbing!




Not to fear though, the operation was a success and the patient survived! The final part was to polish the front plate and bring that classic champagne look back.

Think of it like a mud mask:

The end result is magic. The unit was recalibrated and tested for a good 48 hours of non stop playing both to speakers during the day and a dummy load at night to make sure no further faults were found. It's sound is true to the 70's Marantz tone. A nice warm almost tube like sound, quite enjoyable paired with a good set of speakers you can't really go wrong with this unit. Anyway I had taken some quick modeling shots before it was whisked back to it's eagerly awaiting owner! Thanks for reading!



4 comments:

  1. Hi Alex,
    Beautiful restoration! I'm about to get my hands on this amp and would love to know how you polished up the face? New to all this and need some advice!
    Cheers!

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  2. What would you charge to do a rebuild of a marantz 1070 integrated amp and 112 tuner?

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  3. Thanks for your great photos, I've just had one dropped off at my workshop!

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  4. Love the restoration , I have a 1122dc as well can't beat the sound !

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