Help with Marantz 4270 quadradial


I recently acquired this receiver. It has some problems and i am wondering how hard they are to fix and what might be wrong with the receiver. This receiver is stronger in the left channel than the right. One of the inputs doesnt work correctly. When I plug in my cd player to the front aux input, I only get sound out of the right channel, it works fine through the rear aux and other inputs. When it is working, if I crank it, then it makes my speakers sound crackly, almost like they are blown. I hooked up the same source and speakers to a different receiver and got perfect sound. So its not the speakers. Also the rear channel doesnt really get much output. There is sound, but its pretty weak. Also the tuner is a little off. It still tuned in great once you found the stations, its just the stations are off a little to the left. I really like the sound of the old marantz receivers and im wondering if this one can be salvaged? Also any idea of the worth of this receiver in both current and/or working condition and the potential cost of repairs? I am really new to this and dont know much about them, just that I like the sound when they are working correctly. Ive seen the same model on ebay go for over 200 in non-working condition. The speakers im using for now are polk audio ls50's. I live in Salt Lake City, Utah. So any local references for repair would also be appreciated. Thanks!
aloutah
Xiekitchen, True, most all vintage solid state receivers provide A-B speaker switching and when both pairs of speakers are driven the sound is degraded.
Rrog: interesting observation, probably right.. odd though that all the Marantz and others typically provide "A" and "B" speaker outputs, as if it is totally normal for these units to drive two pairs of speakers in a parallel 4 ohm load...
These old receivers usually need a good cleaning. Go to Radio Shack and get their best electical contact cleaner. Spray all of the controls and switches and while they are wet with the cleaning solution be sure to operate the controls and switches numerous times. Just one dirty switch can cause the kind of problems you are having. Do this first before taking it to a repair shop. Most of the Japanese receivers have good longevity. I own several receivers from the 70s and they all work flawlessly.
The statement of old receivers not working well with new speakers is somewhat true. Most of the old receivers were optimized for driving very efficient 8 ohm speakers. I have tried these receivers with low efficiency 4 ohm speakers and the sound becomes very hard and closed in indicating the amp is not happy with the load at the other end. However, any 8 ohm speaker with at least medium efficiency seems to be fine.
Sorry guys but the comments to the effect of "modern speakers -- vintage amps" doesn't make much sense to me; we're talking about a pair of Polks here, not big Maggies or some dip down to 2 ohms in some 83 db minimonitor...
The question you need to ask is, are you a 70's Marantz afficiendo, loving that brushed chrome finish and knobs, the blue-violet back light, the script type, the wonderful midrange control, and if so, it will be worth 200-300 + dollars to get it fixed... or modded/upgraded. Sounds like a fun project. Go for it.
Its only on the left channel though. The right sounds fine. The speakers sound fine with my 2215 and 2270 as well. Its just this 4270 that gives distortion and makes my speakers sound like they are blown.
Hi Aloutah,

I've got just the man for you!

Go to IREBUILDMARANTZ.COM and tell him Jake from Phoenix,Az. referred you..
He is a 25 yr. Marantz technician who does stunning work! his complete restoration and update runs right around the bluebook on your unit, but when he's done...YOU'LL BE DONE LOOKING...:)

Good luck,

jake
looks to me that your speakers are way under-powered and your receiver is clipping. These aren't definitely for vintage receiver or amp.
What speakers you're driving?
The vintage amps aren't for today's speakers for sure.
Servicing this amp IMHO might not be a large burden as it would seem.
At 36 years old there is probably a lot wrong with this unit.The A'gon Blue book value states $300.00,of course that is for a unit in pristine condition.I can almost guarantee the repairs will far exceed the worth.Probably better to look at something else.This is just my opinion,it's your money do as you see fit.Good luck.