Superscope receiver

[scorpio333]

My buddy picked this thing up at an estate sale awhile back. It was is very good shape for it's age looks wise. I'll admit to doubting it's ability, but it definitely has some magic to it. He used it daily for a few months then it started getting noisy in one channel. I brought it home and got all the dust out of it and deoxit-ed all the pots and connections. Set it up and played it for about 5-6 hours and never heard any noise. Gave it back to him, next day he said it is still noisy.

So he puts it on a shelf for awhile then takes it to Galaxy thinking it needs caps. Vince cleaned it and played it for "hours" and gave it back to him. Now three days later, "it's not fixed".

When I had it, I played it with the volume about 11 o'clock on the volume. My buddy plays it loud, past 12. "If the volume knob goes that far, why not use it?" is his philosophy.

He wants to know if the caps need replaced. I'm wondering if he's just pushing it beyond where he should and is clipping it and/or over heating it. Any thoughts?

[AdamG]

The only common denominator is him and the rest of his system. Do his speakers drop too low? 4ohm or lower? Or is he just bashing the thing thinking it will handle it with grace.

[MacGeek]

I'll speculate that max, clean power is achieved at 12:00 on the volume control, or earlier, certainly not past 1:00.  If he keeps over driving it, it will be noisy, or crap out entirely.

[scorpio333]

I'll be going up to listen to it sometime soon. Here's his description:

This is a deterioration , not noise in addition , it's pretty quiet but at a point left channel sounds like your running it through a guitar pedal & out of a blown speaker

The only common denominator is him and the rest of his system. Do his speakers drop too low? 4ohm or lower? Or is he just bashing the thing thinking it will handle it with grace.

8 ohm 93db 60 watt or so speakers, so they're pretty efficient. Receiver is rated at 15w/ channel. His wife complains of the sound levels so I think he's just going a bit past redline. Turn it down or upgrade to higher wattage amp.

[MacGeek]

Might he be over driving a speaker?  Or maybe a bad xover?

[scorpio333]

Might he be over driving a speaker?  Or maybe a bad xover?

Also a good possibility. We went in on two sets of identical Sansui's. I know the two I have are in definite need of recapping. I plan to take a known set of good speakers with me to help troubleshoot.

[Sir Thrift-a-Lot]

Superscope was owned and made by Marantz for most of it's existence.   Is his made in USA or Japan?   I'm not surprised that it has some magic.   If it hasn't already been done (and especially since your friend like to wind it out) I would think at minimum replacing the big can caps would be in order.

[Kingman]

Sounds like the 15 watts is running out of steam and clipping.

[scorpio333]

Had a chance to go up and listen to his setup for a few hours. Even with the volume pushed to about 2 o'clock (slightly louder than any  sane human should listen) it never made a single bad noise. Vince told him to keep running it and bring it back if it acts up.

Not sure if his is a USA or Japanese model, if I recall it did have Marantz, USA on the tag on the back. Either way, it was a good buy at $20 that also included a cheapo Glenburn TT.

[OldiesButGoodies]

Sounds like the 15 watts is running out of steam and clipping.

he shoots he scores