Marantz 4100 Quadrophonic/Stereo amplifier. w/SQ decoder. SERVICED!

We are one of the only facilities in the Pacific NorthWest that buys, sells and restores reel to reel tape decks. We have over 35 years experience working on these units, and have the tools and test equipment to properly align and bring these decks to life.
We use MRL calibration tapes, and are dealers for ATR tape. We work on everything from mono tube machines to 2" 24 track studio decks. We are reeltoreeltech dot com!
We stock many types of ATR tape from 7" reels to 2", in several formulations. We have about 350 decks in stock at all times. If you haven't yet checked out our website, please do so. Under the 'about us' tab we have a bunch of articles regarding the 'great barn finds' that we've come across this year, netting us well over 100 decks and tons of parts.

We recently picked up three Marantz stereo and quadrophonic pieces with a bunch of reel to reel decks we picked up. These came from an abandoned house in Idaho, whose owner had apparently passed away, with no heirs. The house went into foreclosure when the mortgage payment lapsed, and the new owner of the home got a hold of us, as it was filled with stereo equipment. Even the cars were left in the driveway, go figure! We don't know any back story other than that on these units.

This is the Marantz 4100 stereo and quadrophonic integrated amplifier. It can be run as a stereo or quad amp, with the amp channels being bridged to get 60 watts per channel in stereo mode, and 25 watts per channel in 4 channel mode. It has a ton of inputs and outputs as shown, including two tape loops. All controls and switches needed cleaning, and we also replaced all the dial lights with new ones, as one was burned out.

This unit is equipped with the rare internal factory Marantz SQ decoder. While we didn't have any SQ records, we did verify that the module did pass audio in SQ mode, so we suspect it to be fine.

We checked the bias settings of the amp, and tweaked them to factory spec (they were pretty close). We then ran the amp for 24 hours to ensure long term reliability. From what we could see internally, this amp was likely never worked on, as everything appeared to be stock.

We measured 30 watts per channel (old Marantz units tend to be underrated spec-wise, at 0.02% THD on all channels, as per our Soundtech 1700B audio analyzer.

The unit came in without the plastic feet on it, so we put on 4 replacements that are a hair smaller than the originals (see the picture).

Cosmetically the unit is in good shape, but it has some adhesive residue on the sides and on the top cover. Most of it is gone, but you may want to pull the top U shaped cover, and do it again. There are two faint scrapes on the top of the cover as per the one picture, and we angled the amp to clearly pick out those marks. Under normal use, they are far fainter than the one picture.

We know how to pack these vintage amps, and the unit will arrive intact. We use lots of bubble wrap and styro sheeting around the amp. Any excess shipping charged will be refunded upon sending the unit out.