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Marantz 2230 Unbalanced volume

TellMeWhy

TellMeWhy

Active Member
Hi guys, I recently purchased a very nice 2230, serviced and partially recapped (but with original power and cap coupling caps). The receiver sounds wonderful but I notice that the L channel is quite a lot louder than the R. In fact the balance needs to be turned to the 2 o clock position to become equal. I checked this carefully and it's the same on all inputs, whether in mono or stereo with loudness on or off. I also checked swapping the speaker connections of course. Any ideas?
 
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try switching the rca input cables to see if the issue switches sides if it does its the input device thats the problem if not the next step is to get some deoxit contact cleaner and spray (clean) the balance and volume pot, lot of threads on here about how to do it. all the switches and pots should be cleaned as well. here is one i found and there are lots of others http://www.audiokarma.org/forums/showthread.php?t=207005
if its already been cleaned try again sometimes takes a few times
 
Hi Chris, thanks for your reply. I checked the source signal- in fact the difference is the same whether aux, tape or tuner. The receiver has been restored and all the pots fully cleaned so it shouldn't be that. Do you know if a tired output coupling capacitor could be to blame?
 
i would try cleaning the pots again some are stubborn. im not tech guy so beyond that i wouldnt know but im sure a couple will chime in soon with more ideas i have had 3 or 4 receivers with similar issue and cleaning the pots worked on all of them but one and i had to replace the pot on that one.
 
Check the pre-out / main in connectors and clean them thoroughly plus the jacks themselves. Sometimes there's internal corrosion.

Was the unit known to be balanced and functioning properly before you got it? Was it shipped?

You can try using another preamp to drive the amp section and see if the problem still exists. And then use the Marantz preamp section to drive another known good amp. This way, you can see if the problem is in the 2230 amp or preamp section. That will point to different areas to troubleshoot.

Also check to see if the Mono switch gives you a balanced and centered sound, and if it is at the higher or lower volume.
 
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Also, using DeOxit D5, cleaning the tape monitor, loudness, mono, and Mute switches as well as the selector rotary switch will be important. With the rotary switch, just a small amount of cleaner on the switch contacts, not spray the brown phenolic wafers if present.
 
Thanks for your messages guys and welcome mech986. The unit is clean as can be, shipped from a well respected restorer. Seems like cleaning is not an issue, and the unbalanced sound is same in mono. I tried putting the input directly into the main in and the sound is perfectly balanced- which points to the preamp, right? Is there a way to equalise the L-R channels in the preamp itself? Thanks, Jon
 
It may be a piss-poor volume control. Lower-end models, like the 2230, don't exactly have a high-end volume control and L/R tracking is commonly off at lower volumes. I'd bet it gets better as you turn it up. If so, you may have to live with it, or see if you can fit a new volume control in there.

By all means, I'd try more Faderlube in the control, but the years may have taken their toll for good.
 
EchoWars said:
It may be a piss-poor volume control. Lower-end models, like the 2230, don't exactly have a high-end volume control and L/R tracking is commonly off at lower volumes. I'd bet it gets better as you turn it up. If so, you may have to live with it, or see if you can fit a new volume control in there.

By all means, I'd try more Faderlube in the control, but the years may have taken their toll for good.
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Thanks EchoWars. Actually I did a loud music test, running the receiver in mono, and one channel is definitely weaker than the other. It's not just at super low listening volumes, and not just the volume but the sound quality too. That said, it's not too huge a difference that you'd notice right away...
 
It could be a parts problem but always try the free stuff first.

With the receiver OFF, run the volume from minimum to max 10-20 times.
Power it back on. Any difference?

With the receiver ON, rotate the balance control all the way to the weaker channel. Turn up the volume to where you like it and start exercising the all the controls (except volume) several times. Does any one of them make it jump up a bit? Give the tape monitor button special attention. Any change?
 
If you turn the balance to full left is the volume the same as when it is full right?
Its probably not your issue but on my Marantz 1060 the balance knob itself was not centered when it was put back on. I took the knob off and found true center and now it works like a champ. It was about a full notch off from center

If you get a weaker volume with the balance full left versus full right there is a bigger issue
 
elitopus said:
If you turn the balance to full left is the volume the same as when it is full right?
Its probably not your issue but on my Marantz 1060 the balance knob itself was not centered when it was put back on. I took the knob off and found true center and now it works like a champ. It was about a full notch off from center

If you get a weaker volume with the balance full left versus full right there is a bigger issue
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I bought a Kenwood receiver a few months ago and most of its knobs were not lined up properly, so that is definitely something to look at.
 
Nightwisher said:
I bought a Kenwood receiver a few months ago and most of its knobs were not lined up properly, so that is definitely something to look at.
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There ya go. If the balance doesn't have a center detent to tell you when it's centered, the knob may be incorrectly installed.
 
Y'all think a restorer would send it home with the balance knob installed incorrectly ? Hmmm.

I think it is a coupling cap or bootstrap cap issues in the power amp. It happens. Gets cold enough one time and it is over sometimes.
 
Actually I was lucky enough to have the seller offer to recap the preamp board and replace the transistors there. But sadly now my 2230 sounds really dull and muted. The receiver previously sounded great, and had been partially recapped, but had a louder, stronger, clearer sound on one channel. Renewing the preamp board has equalised the sound quality in both speakers, but now both channels sound pretty bad- so dull it's almost muffled unless you add extra treble. Is a burn in time of caps and transistors a reality I should get used to? Does it really matter which brand of caps are used on the lower value one? I didn't do the work myself- it was done by a very generous eBay seller... The power and cap coupling caps are original and apparently tested as good. The amp sound great direct to the main in so the problem must be in the preamp. Any advice gratefully received! Thanks, Jon
 
No such thing as burn in in caps and transistors. Either it works like it should or it doesn't.

What is your reference? Do you have another amp around? Hook up your source left to one amp and right to the other amp. Connect the speakers -> one to each amp. Play a mono track. If you hear differences like you describe there is actually a problem and you need to figure it out or send the unit back.

edit: I didn't read the part about the amp sounding great bypassing the pre. Sounds like something went wrong then. Can you bypass the tone controls with a switch?

If you feel like troubleshooting it yourself, there are awesome people here that can and will help. But you need to post over in vintage solid state, post links to or post pictures of the schematics.
 
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