Rare and collectable, the Marantz 250M was offered for only one year, between 1975 and 1976. One of the last Marantz amps completely built in the USA, the 250M was an upgrade of the older model 250, with larger power meters, an extra meter attenuation setting, larger knobs, and a new faceplate. The 250M is conservatively rated at 126 watts per channel (into an 8-Ohm load; 150 watts per channel into 4 Ohms). Construction includes close-tolerance components, beer-can sized filter capacitors, and a 16-lb. power transformer.
I have owned this particular 250M from new in 1978. I've used it off and on in my personal system. Overall it has very little use. Everything work perfectly, including the turn-on delay relay, meters, meter switches, and all the original lights.
I've rated the condition 8 for age, but it is really does not have a scratch. The A/C outlet on the back is chipped a little on one side. The red part of meters are slightly faded. The front faceplate, glass and knobs are pristine. The feet are original and un-damaged. The side transistor covers, the case, side heat sinks and rear panel are unscratched and undented. The interior is rust-free, corrosion-free and clean.
Functionally, this unit performs flawlessly. Both channels are well-balanced, and in the absence of input signal, there is no trace of hum or hiss. The meters zero perfectly, and function exactly as they should. The amplifier's circuitry is extremely solid. And the sound quality is superb.
A refurbished unit sold on eBay last month for $1,225. A non-working unit just sold for $406. A currently listed unit is asking $999.99 on ebay. My unit is in pristine original condition and includes the original box, styrofoam liner, owner's manual, warranty certificate, schematic diagram, mounting template and "accessory kit". Well, the accessory kit is just a couple of screws and an allen wrench, but what can I say...