Marantz 140/3200 Issues

[gaspergou]

First time caller. Love the show.

I've got a Marantz 140 and matching 3200 preamp hooked up to a pair of AR3's. And I'm having some problems.

Every now and then, there is a low-level hum that grows into an oscillating buzz and then discharges with a pop...very much like the sound of a charge building up and shorting to ground.

The interesting thing is that when the hum builds, it seems as though I can make it discharge by pulling out any other power cord from either of the two outlets on the same wall.

I have taken the 3200 out of the equation, and the problem still appears. So it would seem that the issue is with the 140, which I purchased off of eBay, and which has clearly been opened up and tinkered with by a previous owner.

There are only a few caps in the 140, and they all look pretty healthy. Of course, there is the one big honkin' cap that I'm assuming is in great shape.

As I read over this, I realize that I sound like a man in denial.

Any advice and/or explanations would be exciting, if not helpful.

And if you've got a schematic, please help a brother out.

[SB Marantz]

Difficult to judge from a distance but i would check , rectifier , ground connection input terminals.

Allso re-cap the whole thing because you can NEVER tell if a cap is healthy or not.
Only when pulling it out and messure the sucker.

Allso check the filter cap and their connection's.

Good hunting!