I picked up a Marantz 2270 in the original box with its shipping box and all of the paperwork, schematic, warranty certificate, including a note from the bank where the original owner must have borrowed 400.00 to help pay for it. Not a scratch on it anywhere all for $50.00. Now here is the problem everything works perfectly for 20-25 min :music: then the right channel gets staticy and drops out. Turn it off and back on 1 of 2 things happen, it starts out perfectly normal and in 3 seconds fades out and gets staticy, or it starts out extreamly bad for 3 seconds and progress better. Either way they end up at about the same static muddy sound. Turn it off for a hour and it is fine for the 20-25min. Any ideas? :scratch2:

Clean pots and switches first! I've cured lots of expensive sounding faults this way.

It sounds to me that you have a beautiful, original unit - so original in fact, that it's never had its controls or switches cleaned. Most likely, that's all you need to do, and you may be able to do it yourself, depending upon how comfortable you are getting under the hood of one of these old classics.

Another possibility is that you may have dirty speaker relay contacts. Usually the dead giveaway for relay contact problems is that the sound is intermittant at low levels, but when you crank the volume a bit, the receiver "clears it's throat" and the static/dropouts go away.

Either of these issues are well within the realm of a careful do-it-yourselfer, and searching this forum for the terms "speaker relay" or "Deoxit" (the contact cleaning compound of choice around here), should yield plenty of threads providing the "how-tos".

If you're not comfortable with the DIY idea, make sure you find a really reputable tech to do the work. One careless scratch on that museum piece you have would severely reduce its value. Echowars is top-notch, and there are other great techs on this forum who 'understand' vintage electronics. Good luck to you - that 2270 is a real keeper!! :thmbsp:

Price is about right. The 2270 is probably the least reliable of the Marantz receivers and it hates anything under 8 ohms load.
Yeah, they do sound good when working.
First thing is to get some Caig DeoxIt and clean the pots and switches, especially the source selector switch and balance control, and the speaker selector.
If it still has quirks, send it to EchoWars for his fine ministrations.

Some 2270's have the pre-out's and main-in's strapped together inside. Others still have the jumpers. Either way . . . go to the pre-out's and run a cable from there into another amplifier known to be good.

What you're trying to learn is this: Is the static/noise coming from the preamp or the power amp? If you hear the static/noise at the pre-out's, using the "other amp" as your tester, then the problem in the 2270's preamp section. If you don't hear the static/noise at that point, then the problem is in the power amp.

If it's the power amp, the differential amplifer transistors and the 2SC945 class-A driver transistor are the most likely candidates. If it's the preamp, the bulk of the preamp is located on a single preamp card, bottomside, about 4-5" from the frontpanel. Get a can of freeze spray and use it to isolate the bad part, likely a leaky transistor.

Best,

Fred Longworth

I have a 2270 with similar issues, the relay wasn't the problem, the front dubbing jacks were losing contact and interupting the signal path. When a 1/4" jack is plugged in these openings, they break the signal path, when you remove it the signal path is "supposed" to be restored, after time, dust and corrosion, the connection won't restore, even beyond deoxit's abilities. I'm going to run jumper wires across the interupters as I don't care to use these jacks anyway, Dave. :no: :music: