• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

4270

  1. D

    Marantz 4270 - Very weak left channel

    Hello! I bought a 4270 about 5 months ago. When I bought it, it has a very weak left channel, basically no sound. You have to turn the volume up all the way to get any sound out. Every other channel works fine. After pulling the pre-main bridges and putting the right preamp into the left main...
  2. E

    Marantz 4270...

    So i decided to work on the literal worst unit you can possibly imagine to work on. I bought the unit used and someone had done some serious damage to all the wires. I think I've gotten all the wires sorted out. Whenever i run switch the power selector switch to 70 watts the DC relay kicks out...
  3. ocdecio

    4270 weirdness - plays for 20 minutes then bright DBT

    I have a head scratcher here. Got a 4270 for parts but decided to try bringing it back to life. One of the filter caps was totally shot, and a trace under the PS board was destroyed, so something really bad happened to it. I reconnected the trace, replaced the outputs and filter caps but still...
  4. Ray122

    Marantz 4270 Help...

    Alright, so I've got a Marantz 4270 with a bad channel, spitting out DC and throwing it into protection mode. Only one of the output transistors was shot, I believe it was the one that handles the negative swing. Otherwise, all the semiconductors on the board and otherwise are testing OK. I can...
    • Ray122
    • Thread
    • 4270 amplifer help marantz marantz 4270 output drivers repair repair channel diagnostics repair help
    • Replies: 6
    • Forum: DIY
  5. jd3rdcoast

    4270 - P800 P/S: No 35V or 14V DC post rebuild...

    HI all, hoping can get some direction on this power supply issue that I'm not getting DC voltage out of after rebuilding. Stated problem from my collector buddy: "was playing a record at low volume, it ended and he was not in room for for 30 minutes when he heard a pop in speakers. Ran into...
  6. P

    Marantz 4270 Frankenstein!

    Hey everyone! Hope you are doing great, got a set of 4270 amp modules with original pair of 50V /15000uF caps (marking great). As this is all I've got I would like to know if someone could give me a hand figuring out what should be done to get it working on 2x70W (don't want to use it as...
  7. bencce

    Marantz 4270 - Digital source to quad sound

    Hi All, this is my firs post :) Recently we moved into a bigger flat and was able to change my audio system for a better one. I bought a 4270 with Pinoeer HPM-900 in the front and Grundig Hifi Box 500 in the rear. I've never dealt with the quadraphonic sound but started to read about it now...
  8. P

    Marantz 4270 Troubleshooting

    We recently had to put my grandmother in a nursing home, and are currently in the process of distributing her belongings to family members. One of these items is her Marantz 4270, which always worked well when it was at her house. However, a family member recently tried plugging it in at a...
    • pcpcpc
    • Thread
    • 4270 marantz marantz 4270 troubleshooting
    • Replies: 2
    • Forum: Marantz Audio
  9. Chris2102

    Marantz 4270 Source Selector

    Hi audio noob here, I have two questions regarding my 4270. My current setup is a Marantz 4270, Marantz 2440, Marantz 5220 and Marantz 6300. Firstly, I have a cassette deck, TT and AUX cord plugged into the back, obviously using the selector switch to cycle through them, but I was wondering...
  10. Richs_Trains

    Marantz 4270 pops when turning on/off

    Hey all, The 4270 I have in the living room has always popped when I turn it on or off through the speakers. I have read threads about dc voltage and such, and I have recapped the filter caps, power supply board and all 4 amps. I have adjusted both the power supply and the amp boards to the...
  11. Richs_Trains

    Marantz 4270 newest victim

    Hey all, In my crazy effort to aqquire every Marantz quad, I picked up a 4270 with a wood case. The 4270 arrived in one piece, the wood case, not so much. Anyway, thank goodness this one worked when I got it, just needed the usual de-oxit treatments and general cleaning. I have re-capped the...
  12. M

    Marantz 4270 - only front MAIN speakers work?

    Dear all, I am trying to restore 4270...currently only two main front (L+R) speakers work (out of 4 sets possible: front main, front rear, remote front and remote rear). I connected an oscilloscope to the ones NOT working, and there seems to be audio signal without LOAD (no speakers connected)...
  13. Marantz Model 4270 Stereo 2 Quadradial 4

    Marantz Model 4270 Stereo 2 Quadradial 4

    I picked this unit up off of Craigslist. I was not planning on doing any upgrading to my equipment that day, but just searched CL to see what was new. This unit came up and the price was good. It came with the metal enclosure and two bulbs burnt out. I replaced all of the 8v 250ma fuse lamps...
    • Theoberheim
    • Media item
    • 4270 marantz model quadraphonic receiver stereo
    • Comments: 2
    • Category: Member's Component
Back
Top Bottom