RCA Caps

Yes, exactly, @gdhal . From the manual for the INT-250:

There are four inputs, two with XLR and RCA and two with RCA only. The XLR and RCA inputs on INPUT 1 (and INPUT 2) are connected so use XLR or RCA but not both. When using INPUT 1 & 2 with RCAs you should have the XLR shorting jumpers in place.

It’s unusual, though, for inputs of an integrated amp to be configured like that. Typically that situation arises with power amplifiers. But I suppose Nelson wanted to provide users with some added flexibility, by making it possible for those inputs to be used with either type of connection. While another designer might have simply made inputs 1 and 2 XLR only.

So with the INT-250 a shorting plug should not be put on the RCA connectors of inputs 1 and 2 if the corresponding XLR connector is being used.

Best regards,
-- Al

There is a small operation making and selling true RCA shorting plugs: Aurora Tronics in Sandy Hook, CT (phone number 203/426-9599). I bought some a couple of years ago, and they were cheap: $19.95 for 20 plugs. They also offer RCA phono cap covers (non-shorting, for outputs), at $7.95 for 20. They sent them to me with free shipping! Cardas’ protective caps look nice, but do nothing, claims for providing shielding against RF and EMI notwithstanding.

@bdp24

Appreciate that recommendation, but it appears to be a dead-end. The number is not valid, and the 860 version of CT area codes is a different organization. Googling for this outfit is also unsuccessful.

So, are there any other recommendations as to where to obtain caps and shorting plugs?

Search at eBay for "RCA shorting plugs" (without the quotes) and you'll find numerous sellers offering them, at low prices.

Best regards,
-- Al

Like the Cardas Caps they don't having to be shorting type caps to be effective. Cardas type caps are simple covers for unused input and output plugs. They should be placed over ALL input and output plugs for max benefit. Copper foil can be used in lieu of the real McCoy. 

I found the Aurora Tronics plugs in a 2015 ebay ad. It doesn't matter who makes them, as long as the hot center pin and outer ground are soldered together, to create the short. Anything less is merely cosmetic.