Search found 1209 matches

by Maschinengeist
Sun Feb 28, 2010 11:47 am
Forum: HELP!
Topic: Farfisa Bravo with no sound?
Replies: 2
Views: 789

Re: Farfisa Bravo with no sound?

The schematics are here: http://www.musicparts.com/products.asp?Company=Farfisa

And the problem is surely a faultive pair of transistors at the outputs.
by Maschinengeist
Sat Feb 27, 2010 8:21 pm
Forum: HELP!
Topic: Oberheim OB-12 Resources
Replies: 3
Views: 749

Re: Oberheim OB-12 Resources

As far as I know, there are no schematics in existence.
by Maschinengeist
Sat Feb 27, 2010 4:02 am
Forum: HELP!
Topic: EMU XBoard 61 faulty mod wheel problem
Replies: 5
Views: 5339

Re: EMU XBoard 61 faulty mod wheel problem

That's good news. Thanks for sharing. I would have suspected a defective pot inside the wheel before checking the manual.
by Maschinengeist
Sat Feb 27, 2010 3:58 am
Forum: HELP!
Topic: How do you repair an Aftertouch Strip?
Replies: 4
Views: 1701

Re: How do you repair an Aftertouch Strip?

I agree with rhino, it is quite a job.
by Maschinengeist
Sat Feb 27, 2010 3:55 am
Forum: HELP!
Topic: Power Supply problem with TR-707
Replies: 25
Views: 3710

Re: Power Supply problem with TR-707

If you get -10V and +5V and you get a light show it means that the problem is elsewhere outside the power supply. We'll have to move toward the CPU just to see if there's not a defective component overpowering the 707. Wish I had a 707 to test on as we speak. It would be faster. But hey, it's an edu...
by Maschinengeist
Thu Feb 25, 2010 3:20 pm
Forum: HELP!
Topic: HIss on Novation Drumstation
Replies: 2
Views: 234

Re: HIss on Novation Drumstation

You should never use a higher voltage PSU than necessary. Change your power adaptor and it should run fine. Cherck the polarity of the tip.
by Maschinengeist
Wed Feb 24, 2010 5:01 am
Forum: HELP!
Topic: Alpha/MKS left channel Chorus/BBD issue(w/ audio example)
Replies: 2
Views: 394

Re: Alpha/MKS left channel Chorus/BBD issue(w/ audio example)

Lemme check my service manual and I come back to you with possible hints.
by Maschinengeist
Wed Feb 24, 2010 4:49 am
Forum: HELP!
Topic: Akai S900 Help Needed
Replies: 39
Views: 8481

Re: Akai S900 Help Needed

Corrupted OS, maybe. MIDI circuit, maybe. I'll try to think about your problem in the next few days.
by Maschinengeist
Wed Feb 24, 2010 4:43 am
Forum: HELP!
Topic: EDP WASP
Replies: 10
Views: 397

Re: EDP WASP

The wasp service docs are here: http://www.synthdiy.com/show/?id=648
by Maschinengeist
Wed Feb 24, 2010 4:34 am
Forum: HELP!
Topic: Power Supply problem with TR-707
Replies: 25
Views: 3710

Re: Power Supply problem with TR-707

After D1 you should get about 11.3 VDC and 5 VDC at the regulator (your black probe on the common and the red one on the out pin). Let's see if the +5 VDC circuit is fine.

About the external power supply, it's normal that it reads 14 V without a load. It works ok.
by Maschinengeist
Mon Feb 22, 2010 3:47 am
Forum: HELP!
Topic: Power Supply problem with TR-707
Replies: 25
Views: 3710

Re: Power Supply problem with TR-707

The power supply schematic:

Image

We'll work from there
by Maschinengeist
Mon Feb 22, 2010 3:10 am
Forum: HELP!
Topic: Power Supply problem with TR-707
Replies: 25
Views: 3710

Re: Power Supply problem with TR-707

Thank you for the compliments. I am not used to that. Don't despare, we'll have your 707 up and running. I'm quite busy these days and can only afford to write 1 or 2 liners, as you might have noticed. Lemme check my service manual, which I didn't have time to do so far. Nor get near my simulation p...
by Maschinengeist
Sun Feb 21, 2010 8:13 am
Forum: HELP!
Topic: Oberheim OB-12 bin file needed
Replies: 2
Views: 144

Re: Oberheim OB-12 bin file needed

Don't have it, will ask around.
by Maschinengeist
Sun Feb 21, 2010 8:10 am
Forum: HELP!
Topic: Juno 60 Help!
Replies: 6
Views: 294

Re: Juno 60 Help!

A bad solder joint would do that. I'll have to unearth my service manual for more possible causes.
by Maschinengeist
Sun Feb 21, 2010 8:02 am
Forum: HELP!
Topic: Noisy synth circuits..
Replies: 12
Views: 624

Re: Noisy synth circuits..

You need to have your instruments checked. Many things can explain the buzz. The first suspect is the power supply itself.

For the record, capacitors hum and transistors hiss.