Noisy Headphone Jack on Marantz 1030?

[Ak1337azn]

Guys, I recently picked up an integrated Marantz and it sounds great--save for the fact that plugging in a pair of headphones results in some fairly noticeable static and perhaps even some faint humming that won't change despite any volume adjustment.

To be clear, there's some faint static that's heard through my speakers as well, although it's my understanding that this is quite normal. I've tried cleaning the jack with some contact cleaner and lube and I've already gone through every other pot and switch I could find.

Additionally, this particular model has pre-out/main-in jacks in the back. I noticed removing the jumpers does away with any sound completely (including the static). Of course, I went and cleaned these up as well. No dice.

Am I right to assume that the fault lies in the transistors? If so, why is it that the speakers sound just fine? Any insight would be greatly appreciated. I also wanted to throw in there that my 2215b sounds just fine through my headphones.

Thank you.

 

[Binkman]

greetings;
Your experience level is showing and that's not bad.

pre-out/main-in jacks in the back. I noticed removing the jumpers does away with any sound completely

although cleaning was good. static is not normal either.

To be honest, considering age alone there is a lot of work required and probably an upgrade or two I think. Certainly not a quick fix, Im assuming if all orig. and if you're not experienced w/test equipment etc.? your call. e.g. sell as is with noted issues.

 

[century tek]

Removing the pre-out / main-in jumpers just separates the preamp and controls from the main power amplifier. If it is completely silent then it stands to reason that the main amplifier is working properly and that there is a problem with the preamp.

If you have another amplifier, connect the Marantz pre outs to another amplifier with speakers and see if it still produces the hum or static through the speakers or headphones, one or both channels. This would then point to the preamp in the Marantz as being the problem.

If you happen to get your hands on another integrated receiver/amplifier with pre-out / main-in options, then you can connect its pre-outs to your Marantz main-ins and use the Marantz as a straight power amp. This would just rule out the power amp section in the Marantz.

 

[restorer-john]

Faint hiss is perfectly normal, static is not.

As for the low level hum, I'd be looking at the power supply PCB and its capacitors- if they are the early black Nippon Chemicons they will likely need replacing and/or have glue/leakage corrosion on the legs.

 

[onplane]

As century said, the problem is clearly in your pre-amp OR devices attached to the pre-amp.

Your first step is to unplug everything and see whether you still hear the static and hum (select Aux). If the noise is gone, then your problem is one of the attached devices.

If the noise is still present, try reversing the 110v plug. (Natrually, this will not work if the plug is polarized). Next try a different 110v outlet. (There is a pinned thread on ground loops you should read).

Regards,
Jerry

 

[Ak1337azn]

I think I've narrowed it down to noisy transistors in the preamp section. Saw that a previous poster had replaced them all with 2SC2240s. This being my first time doing this level of restoration, can someone comment on how to make sense out of this circuit board? I can't seem to make out any of the soldering points for the transistors.

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• Ak1337azn
• May 17, 2018

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• Ak1337azn
• May 17, 2018

 

[Ak1337azn]

Never mind. I can see why the service manual comes in handy now. Still difficult to get my head around at first. I still wanted to get other people's input to see if this would likely do the trick.

 

[Ak1337azn]

Additionally (last post, I swear), I wanted to make sure these are the parts I need from Mouser. I saw that 2SC2240s were hard to come by, but that the 1845s might be a good alternative. Problem is, idk what FTA means although the transistor shape seems in line with what's already installed.

https://www.mouser.com/ProductDetai...GAEpiMZZMshyDBzk1/Wi8oN7VHZ91Ok7yYQ9zR8%2b88=

Thank you to everyone who's entertained my posts so far.