New hiss in vintage Marantz 4300 left speaker

[spurlockscotte]

Restored several years ago and sounded great. Recent move. Hiss from 2 of the 4 speakers in the left cabinet (Pioneer HPM-1100). Does not vary in loudness with volume setting. Have unplugged everything plugged into the power strip. Turned ceiling fan off. Checked speaker wiring from amp (14 ga stranded). Is the left gang of the volume pot bad? Would like troubleshooting hints, please without taking it apart if I can (weighs a ton). Hiss is low volume and persistent but only from the midrange and bass speakers. Help please. Thank you.

 

[Delta Prime]

Restored several years ago and sounded great. Recent move. Hiss from 2 of the 4 speakers in the left cabinet

If you restored several of them years ago then you should have no fear in opening them up.
Have you tried switching speakers right to left left to right see if the hissing persist?

 

[spurlockscotte]

I didn't restore it. I paid someone. Good idea about swapping speakers though. Overlooked that. Thank you.

 

[Delta Prime]

I didn't restore it. I paid someone. Good idea about swapping speakers though. Overlooked that. Thank you.

You're very welcome. I was kind of hoping you did restore them.
I know they're very heavy but I can't pass up the opportunity to get someone to open it up.

 

[spurlockscotte]

You helped. Swapped the speakers. It is in the amp. Left channel. No control makes it louder or softer. When the volume is turned way up (no audio input in any of this), a hum emerges, but I presume that is normal. No crackle, etc, just the hiss from 2 of the 4 drivers.

 

[Delta Prime]

Pioneer HPM-1100)

Is that all the information you have on it. I'll see if I can't find a schematic. That'll give you enough time to go grab your toolbox and open that bad boy up.
By the way.... I have never done this before!!

 

[spurlockscotte]

I have the schematics. And the tools. I was hoping this might be something common - to diagnose and fix. My #1 suspect would be the 48 year old dual gang pot volume control. Out comes the soldering iron and scotch.