Hello. You are offerding on a Beautiful Marantz 510MR power amplifier. Serial number 1572 as indicated on the rear plate. This amplifier has been professionally restored to the manufacturers specifications, but with the audiophile in mind, using only the best audio grade parts. This is not an average restoration, but a meticulously cleaned and rebuilt amplifier with a quiet noise floor, putting out over 250 watts per channel at 8 ohms.
The restoration:

The face plate, and all PCB\'s were removed from the chassis and cleaned of any dirt.

All potentiometers and switches were flushed several times with Deox it and lubed emitting no noise.

All oxidation and corrosion was removed from the speaker terminals, RCA jacks and all ground terminals.

All electrolytic capacitors on the amplifier boards were upgraded with ELNA Silmic II and Nichicon Fine Gold high grade audio capacitors.

The differential pairs were upgraded with Fairchild lownoise BJT\'s and Hfe matched exactly.

All other electrolytic capacitors were upgraded with Nichicon PJ series long life capacitors.

All film capacitors were upgraded with Panasonic ECW low noise metalized polypropylene film capacitors.

All diodes and zener diodes were replaced with new ON Semiconductor devices

The filter capacitors were upgraded to new Kemet ALS 12,000uf - 100v capacitors.

The relay was replaced with a new Omron 48v relay.

The rectifiers were replaced with new IR fast recovery rectifiers.

All output transistors were replaced with new On Semiconductor devices and reinstalled with new ceramic thermal paste and mica insulators.

All PCB\'s were inspected and re soldered in any areas needed.

The fan was replaced and performs quietly as it should.

The bias and DC balance were adjusted to the manufactures specifications.

After bench testing the amplifiers power was 296 watts per channel before clipping, both channels driven @ 8 ohms with a 1 kHz signal. 576 watts per channel @ 4ohms before clipping, one channel driven.

With the exception of a small bump in the filter capacitors, all component values were kept the same to preserve the sound that Saul Marantz intended. By replacing these 35+ year old parts, which are dried out, creating noise, and/or out of spec, that classic sound quality is restored. There are no disappointments here. The noise floor is silent, sound stage broad and vocals centered. The faceplate I would rate a 8 out of 10. All corners are sharp and the finish beautiful but there are 3 small nicks around the word Marantz and a small swirl around the top left bolt as seen in the pictures. This unit is very clean inside and out and highly sought after.
FedEx shipping includes tracking, insurance and a correctly double box. Please contact me with any questions.
I offer my services to anyone interested in restoring their vintage components. I personally warranty everything I restore for six months. Please email me if you are interested in bringing your music back to life with service that far exceeds standard. As an audiophile, I am very passionate about rejuvenating some of the best components ever built for the people who appreciate them and have plenty of references. Some of my bigger works can be seen at Audiokarma. My handle is Salbreth1. Enjoy the music.

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