I need help

What I have used with phono preamps in the past...

1:  A basic RCA which has the Hot shorted to the Ground for use in unused INPUTS.

2:  An RCA plug with a resistor soldered between the Hot and Ground for use in unused OUTPUTS (think I used a 100 K OHM in mine, but don’t recall why).

I used the 2 above to reduce RFI and other noise contamonants on really inexpensive ($25) battery powered stereo phono preamps used as mono preamps (thus the unused inputs and outputs).

The variable load switch on your amplifier only affects the phono 1 inputs (phono 2 is set at a fixed 47 - I think, but it is "fixed" to a single setting).

I would just use phono 1 for now and see how it sounds on the different settings.

I agree with Parker that your technician should be remedying the situation.

PS:

I can't see the photo you linked, but I'll Google later to see if I can find something.

DeKay

Here’s a downloadable user manual (I was off by 3 as phono 2 is fixed @ 50-:).

https://steampoweredradio.com/pdf/sansui/manuals/au7700%20operating%20instructions.pdf

I’ve seen/used this amp when it was new (lots a veteran’s were buying it @ PX discounts just after the end of the Vietnam war) and I do not recall the plugs you are referring to - nor could I find a pic of them in use.

My brother-in-law used one with AMT1's for a while and the pics brought back memories.

DeKay

It had what I think were jumpers connected to the right and left entry RCA connectors of Phono 2 that I suppose were, in the absence of the Phono 2, to simulate it.

I also suppose that the jumpers have an specific impedance.

Those are plastic cover to protect the RCA jack from dirt, dust, oxidation or corrosion, not a shorting plug or phono impedance plug.

You can purchase them on eBay or Amazon...

OK - found a pick of Sansui RCA Phono Input shorting plugs on a later Sansui model from 1978, but you have to be registered (AudioKarma) to view the pics.

It’s the pic in the first post and the plugs have a paper instructional tag attached to them.

I don’t post there, but I recently registered because I like the site.

https://audiokarma.org/forums/threads/installed-phono-shorting-plugs-no-difference-noted-but-not-surprised.1078302/

DeKay

"Well, if working the amp without them won’t damage the amp, I’m OK."

It will not damage the amp without them. They are only necessary if you want to use an outboard amplifier or preamplifier with your unit.