I need help

Thank you viridian, dekay, celtic66 and dill, very much for your help and I also want to apologize for taking too long to give you an answer. Aplril 21 is a national holiday down here in Brazil and I have gests that got me very busy.

First of all it is really a shorting plug for the right and left inputs that I’m  looking for.

Here is a picture of the rear panel of my amp with the two shorting plugs connected to the Phono 2 input channels.

https://www.dropbox.com/home/Public?quickview=id%3AHADsFIwKRTgAAAAAAAAFTw

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

I found many plugs on the net but none show the resistance. Can I use one with zero ohms or a resistance will be necessary?

I am stuck at "technician lost these jumpers". Why wouldn't he replace them?

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...