need help with marantz 2325

[marantz_marc]

picked this up yesterday and was told the right channel was fuzzy. I figured it just need a cleaning. I cleaned all of the front switches and the right channel is still fuzzy. before I cleaned it the right channel would go in and out, but now it seems stable at least in the sense it doesn't cut out. maybe I didn't clean the volume switch well enough? the pots are kinda hard to get to. I am using deoxit.the channel seems fine at lower levels and then gets fuzzy when the volume is turned up. anybody else know any tricks? any help would be greatly appreciated.

[Lefty]

picked this up yesterday and was told the right channel was fuzzy. I figured it just need a cleaning. I cleaned all of the front switches and the right channel is still fuzzy. before I cleaned it the right channel would go in and out, but now it seems stable at least in the sense it doesn't cut out. maybe I didn't clean the volume switch well enough? the pots are kinda hard to get to. I am using deoxit.the channel seems fine at lower levels and then gets fuzzy when the volume is turned up. anybody else know any tricks? any help would be greatly appreciated.

Well it could be so many things it's hard to predict. Cleaning again could do the trick, but proper troubleshooting would utilize test tones and a scope and then follow the signal path until the problem stage shows up.

There is one thing you can quickly do to half-split the problem between the preamp section or the main amp section. This receivers has preamp out/main amp in RCA connectors in the rear. Take a pair of RCA cables and hook the right channel preamp out to the left channel main amp and the left channel preamp out to the right channel main amp input.

If the problem stays with the right channel then the problem is somewhere in the main amp section, including the speaker selection switch and protection relay. If the problem moves to the left channel then the problem is in the preamp section, it's power supply voltages or controls or connectors.

It's a divide to conquer type of attack :thmbsp:

Lefty

[oldtubes]

Try Lefty's tip on using an RCA cable to cross connect the pre-amp and main amp at the pre/main jacks on the back of the receiver. My 2325 would cut out on both channels, but when using the RCA cable it was fine. I sprayed deoxit into the pre/main jacks to clean the internal conections which fixed it.

[marantz_marc]

I did the test you recommended and I wanted to clarify the results. the fuzz stayed in the speaker connected to the right speaker terminal, but the balance selector was reversed, that is the right speaker was the Left speaker on the balance switch. so I'm assuming that means the fuzz is still in the right channel but I just wanted to be sure.

thanks

[Lefty]

I did the test you recommended and I wanted to clarify the results. the fuzz stayed in the speaker connected to the right speaker terminal, but the balance selector was reversed, that is the right speaker was the Left speaker on the balance switch. so I'm assuming that means the fuzz is still in the right channel but I just wanted to be sure.

thanks

Yes, that is correct and because of the cross connected cables the balance control should have worked backwards, you can remove the cable now.

So you know you need to concentrate on the main amp right channel. Things to check include the speaker selection switch contacts (you might change your speakers to the B terminals and check again). Sometimes a dirty contact on the speaker protection relay can cause a weak, intermittent or fuzzy sound. Of course it could be a bad electronic component in the main right channel but that is probably something left to a experienced troubleshooter.

Lefty

[marantz_marc]

well I want to change the fuses on the 2325 but I ahve a couple of questions. the internal fuse is a 200 ma 250v and unfortinuately the closest radio shack has is a 500 ma. I'm assuming this wont work?

also the outside fuse is a 6 amp but it's not glass, it's made of some solid white material? I'm new to all of this so bear with me. should this fuse be replaced?

thanks

[oldtubes]

It sounds like the problem is in the right channel main amp, the speaker relay, or speaker switch. Did you try using the remote speaker jacks? Most of the time the speaker relay and speaker switches cause cut outs at low volume and when the volume is increased the sound cuts back in. This is just the opposite of what you are describing. A long shot here, are all four output transistors installed in the right channel? If a pair were shorted and were removed to get the unit to power up may give the symptoms you are describing. A single pair of outputs or just the driver transistors will drive a speaker at low levels. This may depend on the design of the amp but my Pioneer SA-8500II worked this way.

[marantz_marc]

thanks for your help lefty. so where is the speaker relay and how do I clean the contacts? if cleaning doesn't take of the problem it's going to have to go to a shop. she's in near mint condition and has to be brought back to full health.

[Lefty]

thanks for your help lefty. so where is the speaker relay and how do I clean the contacts? if cleaning doesn't take of the problem it's going to have to go to a shop. she's in near mint condition and has to be brought back to full health.

Fuses are usually best checked with an ohm meter. The relay is mounted on a power supply board deep inside the unit. It's been several years sense I've had a 2325 so my memory is fussy like your sound :D

Anyway some relays unplug from a socket but most are soldered in, so the fix some try is to just remove the clear case so that access to cleaning the contact can be made. These are tricky procedures for the inexperienced so beyond switch and control cleaning you may consider getting a pro to work on it, the 2325 is a top of the line receiver and worth the investment. One really needs a service manual, proper test equipment and of course the experience. I would not just give it to any odd local tech unless someone recommends them for vintage repairs, there are a lot of hacks out there that can take your money and ruin your receiver. There are several very good techs on this forum that do this work as it should be done.

Don't forget to try the speakers on another set of speaker terminals or at least try a set of headphones to see if the right channel is fuzzy there also or not.

Good luck
Lefty

[marantz_marc]

well checked the headphones and I couldn't detect any distortion. I think at this point I probably will take it to a tech. I know a shop that's been around for ages, they deal in "vintage" equipment and ask high prices for their gear, which is quite nice. It's owned and run by an elderly couple and the man seems to be like a great old timer who knows his stuff.

one more thing, should I try to switch the left and right transistors?

[Lefty]

well checked the headphones and I couldn't detect any distortion. I think at this point I probably will take it to a tech. I know a shop that's been around for ages, they deal in "vintage" equipment and ask high prices for their gear, which is quite nice. It's owned and run by an elderly couple and the man seems to be like a great old timer who knows his stuff.

one more thing, should I try to switch the left and right transistors?

Hold on there MM, if the sound is good at the headphones you are pretty much home free of relay and electronic component problems as the headphones are driven from the amp outputs just before the speaker selection switch, and that is good news. Have you tried hooking your speakers to the 'B' terminals yet? It really is sounding like a flacky switch contact or bad speaker output terminal. You could very well be able to fix this before spending $$ :thmbsp:

Lefty

[marantz_marc]

I have tried both sets of speaker terminals and the distortion appears in both. let me know what to try next.

thanks

[Lefty]

I have tried both sets of speaker terminals and the distortion appears in both. let me know what to try next.

thanks

Well I would put extra effort to try and get a good contact cleaner, De-oxit D5 is one, and really work over the speaker selection switch. It can take quite a few dozens of fast switch motions back and fourth to get the cleaner to work and then sometimes several treatments.

If that doesn't work then I guess it's off to a tech. However be sure you tell him that the headphones work distortion free.

Oh I assume you have swapped speakers left and right, it would be embarrassing to find a FUBAR speaker at this stage, but you did say that you were told of the fuzzy channel before you received it :yes:

Lefty

[hmmmshai_hulud]

Remember to use DEOXIT FADERLUBE on the volume,treble,bass, etc.., and regular DEOXIT 5 on "click" knobs like speaker selection, input selector, etc....
It's pretty important.