Setton RS-660

mafatone

New Member
I picked up a Setton RS-660 about a year ago and finally had a chance to examine it. It flickered many times upon startup but then the relay would finally kick in. Pulled out the Bose 901's series 1 that I never played. I enjoyed the sound but noticed that the Setton was getting pretty warm with the sound dial at 9 - 12 o'clock. I just figured it was old inefficient 70's output transistors. Did a little research here and found a post by k7sparky with pictures of the power switch and how to cure the problem. Didn't have to remove the faceplate to get to it and took k7sparkys advice by taking my time. Opened up the power switch and saw two sets of contacts that looked like old style ignition points. They can handle high voltage but I don't think they can handle the amperage that this monster demands. Cleaned out all the black ash with Q Tips, contact cleaner and brass brushed the contacts. Slapped it together and no more flickering or relay chattering. I noticed that the heat was at a minimal at the same volume settings. I'd like to believe that the reason why she was running so hot in the beginning was because it was staving for amperage and the output transistors were working overtime to produce the output. So, if your Setton is running hot, clean those contacts in the power switch before you blow those almost bullet proof transistors.
 
Forgot to mention that when I got this unit it was corroded all white from the salt air from where I live. Some rich guy probably had it in his garage in his 3 million summer home. I used Mothers Metal Polish on all of the aluminum parts and wow. I swear by this stuff. I use it to clean the plastic headlight covers on all my cars and the trigger groups on my guns.
 
Welcome. Setton RS-660 is one of the nicest looking receivers, IMO. Vintage power switches can be a problem in certain models. I like to power them using a power switch to save the contacts. Good catch on yours, cleaning contacts is always good. For faceplates, metal polish is good for bare metal but not good for anodized finish. Not sure which the Setton has but most of the Silver Era receivers were not bare metal. I never use polish on any of my gear. The strongest cleaner I use is dish soap. Your heat concerns are another story. Bose 901 are low impedance and tough on amps which can cause them to heat up. An amp that is out of bias adjustment can also run hot.
 
Back
Top Bottom