Vintage Synth Explorer Forums

Hey there,

I posted here before regarding this, but I think my question was a bit unclear. Now a litte more precise

Does anyone know what capacitors are used in the octave dividers of a Philips Philicorda GM751, the version with transistors? Info about those used in a GM752 could also help, as it seems to be the same technology.

The problem is, that I could only find two manuals on the internet, one complete one for the GM751, but tube version, and one for the GM752, but with missing infos about which capacitors are being used (maybe there's pages missing). If anyone can provide me with another manual, that would also help massively

Thanks so much,
Miro

Why can't you read the values off them? Are they completely destroyed?

Hey Tomas,

thanks for your reply! Maybe I miss something, I am not super experienced with these kinds of works, but the capacitors are covered with some kind of insulating jacket, you can see the red ballish ones here in this image:

http://www.wernbo.de/Philicorda%20752/P ... _752_8.jpg

I suppose it's not possible to read off the values?

There should be something written on those? But they don't look broken. Are there specific ones that you think are broken? It would be unwise to try to replace all of them. What exactly is wrong with the instrument?

Well, no, actually I am not sure they are broken. The thing is, I know for sure that there's a problem with my second octave divider on the F note. I can play the highest and the second highest octave without any troubles, all the lower ones just get weaker and weaker, so I know that there must be something broken in that specific "island" or group of parts, but I don't know which, so I thought I'd replace all the parts in that area that could theoretically be the source of this problem. I already figured out what the transistors are based on what's written on them, but know nothing about the capacitors. You think if I'd build them out of there I could read their value off them somewhere?

PS: the photo I sent you was from the internet because it was better quality than the ones I took when I had opened the organ, but it looks identical. You can't see any superficial damage.

Have you tried asking this very question over at www.analogorgel.de? There's quite a bit of knowledgeable people around who might be able to help out.

Stephen

Thank you so much so far, I'm trying the analog organ forum now

Sorry to dig up an old thread, but did you ever manage to find the service manual/schematics for the transistor version of the GM751?