SD-135 Natural silver, in great condition. This unit is clean and bench tested. The amplifier was recently returned from the factory, where I sent it to be serviced prior to selling it. It did have a bad RCA input jack, which was fixed. They bench tested it as well and found nothing else wrong with it. See email from AR below.
I have owned the amp for (5) years. It has powered a pair of efficient TAD 2402's and so hasn't been pushed. This is by far the best sounding amp I've owned, including a few AR tube models. Original box in good condition. Original power cord. Non-smoking home. No pets. February 2, 2018 – email from Audio Research:
Please see below the Tech notes from Donn Anderson for the work performed on your unit.
Tech Repair Notes:
Service Tech Report Notes:
Resoldered open connection to left channel RCA jack. No other problem found. Gain is normal & sonics were found to be good in listening evaluation. Test ran. Final test okay.