if it works, did I fix it?

[Milkmansound]

a while ago I bought a yamaha FM synth that was broken off ebay, and the seller felt bad and refunded my money saying there was no need to send it back.

So I found a switching power supply that would work, and kind of traced stuff around to get it to work - and it now seems to work just fine. However, there are a few things that are not connected to anything that were before - this is a useless question since even I do not have the schematics - but is it going to be ok? I ran it for about 30 minutes today and played with all the presets with no apparant problem (well, teeny bit of noise but that probably has more to do with the voltage to the output being a little lower than the original PSU - but its barely even noticiable in headphones that were cranked to the maximum)

the output is based of JRC4558 opmps, and is now getting +/- 12 VDC rather than 15 - the rest of the synth operates of of 5VDC. I think it will be ok... but if it dies, I guess it was all free. Better track with it soon eh?

 

[peter purpose]

If it works, it works.
Send your man half his money for good karma.

peter

 

[pucho812]

hey as long as it's working. it's working. If you fixed it and it wasn't working b4 and you didn't make a deal for $$ if you would be able to get it working, then I would pay a dime but that is just because no deal was made. If anything for good karma I would buy him beer for his time.

 

[chrissugar]

Karma and beer. Best association I heard. :grin:

chrissugar

 

[radiance]

One day you'll make something "beautiful/strange" from all the leftover's..... :roll:

 

[Milkmansound]

the guy told me to keep it and fix it - he never tested it before he sold it.

Cool, well, I guess it works - I am going to try and use it today a bit - and leave it on for a while. If it dies - well, I can try something else in there!

 

[tony dB]

most of these things don't sound any different on 12 or 15 volt btw.
the noise will not be less if you get closer to the theoritical value I think.

opened a few of those back in my MI-days and loose contacts/broken PSU-solderingpoints are most of the sources of problems

0,02 euro

Tony

 

[tony dB]

if in doubt with your Karma, ask the man what he thinks would be a fair deal. Also ask upfront how much a pro repairshop would have costed to fix it. Work your way in between and you'll be very PC :grin:

You can also take some Karmacredit and pay him back in a few lives from now depending on your current financial status... :wink:

Tony

 

[Milkmansound]

we are all set - me and the seller. It was months ago, and he said I could keep it to expiriment on even though I wanted to send it to him with the refund money. Its not a big deal. I used it today, and all seems fine. Cool! Now how do I program an FM synth?

 

[chrissugar]

Hi Milkmansound

You didn't mention what FM synth you have (four operator, six operator).
Anyway, FM synthesis is not that intuitive like analog synthesis. There are some tutorials on the net about FM programing. Try a Google.
You can make FM programing easyer if you have an FM synth editor on a computer. To do it on the small display it is a real nightmare. Also you can find tons of patches on the net.
As an advice I think the best idea is to create a two active operator patch and modify parameters to learn how they interact. After that you can experiment with more operators and more complicated patches.

chrissugar