Cleaning Vintage Amps
Hello Skip how are things with you? I have just bought a 1960's TOA PA amp model HA355 on eBay. I found the schematic online and it looks interesting, with a solid state rectifier and 12AX7 and ECL82 tubes. I don't know if it will prove to be a good harp amp but it was really inexpensive so worth it I think just for the learning experience. Apparently the tubes light up but there is no output - I'm going to start by cleaning the tube sockets because they are filthy.
Can I ask your advice please on cleaning an old amp like this, both the fascia and the circuitry? Do you use any chemicals (other than WD40 on the tube pins to clean the sockets). The power transformer Is a bit rusty - is metal polish ok to use on the supporting structure of this?
Thanks
Joel
Thanks very much Skip, I'll give you a call. It wasn't sold as working and only cost £25 so seemed worth a punt. There was no output at all when I turned it on. I had a little look and found that there was no voltage getting past the 2w resistor between the first two power supply capacitors so I bridged that with a similar value resistor (may have been a bad idea) whereupon a loud hum emanated from the speaker (unaffected by volume control) and a bit of crackle. Nothing from mic. Then a suspicious burning smell so I turned it off in a hurry.
Joel
Hello Joel- Wow! That is a new one to me. Cleaning it up cosmetically is one thing, but we need to see if we can get it going first! In this case, I think it would be best if you give me a call (days) to chat about it. First question: Was it sold to you as working?
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