Search found 496 matches

by adamstan
Sat Sep 10, 2016 11:30 pm
Forum: HELP!
Topic: MKS-80 VCO calibration problem / loosing linearity
Replies: 4
Views: 2731

Re: MKS-80 VCO calibration problem / losing linearity

The problem must then lie somewhere between DAC output and VCO D1 input. It might be a problem with S&H / demultiplexing circuit that provides control voltage for this oscillator. I'd check IC17 (4051 multiplexer), op-amps IC24 & IC30, and capacitors C32 to C39. IC16 multiplexer (4051), IC23 & IC29 ...
by adamstan
Sat Sep 10, 2016 9:49 pm
Forum: HELP!
Topic: Classical organ - replacement parts issue
Replies: 7
Views: 952

Re: Classical organ - replacement parts issue

74HC04 is CMOS chip, but made to be compatible with TTL levels - 0-5V. See that the chip at your picture, MM74C04 has second number on it, which is CD4069 - that would be standard CMOS inverter, which is compatible with wider voltage range. I'd try this instead of 74HC04.
by adamstan
Tue Aug 16, 2016 5:22 pm
Forum: General Synthesizers
Topic: Testing
Replies: 16
Views: 2608

Re: Testing

1,2,3, testing :-)
by adamstan
Thu Jul 21, 2016 6:45 am
Forum: General Synthesizers
Topic: Yamaha DX7II-FD to Control TG77? Or Something Else?
Replies: 20
Views: 2820

Re: Yamaha DX7II-FD to Control TG77? Or Something Else?

I I could not get to 127 on: Yamaha SY99 Yamaha VL1 Both Yamahas topped out at about 115, and that was hitting c# really hard with two fingers. I suspect in normal playing it rarely goes above 100. It's the same with my DX7II. It seems that's just the way it has the key scanning timer set up in sof...
by adamstan
Mon Jun 13, 2016 3:25 pm
Forum: General Synthesizers
Topic: Moog model D reissue
Replies: 166
Views: 32381

Re: Moog model D reissue

Or even F - that Welsh clone from the '90s was called "E" AFAIK.

BTW I find it pretty strange to call that synth "Moog Model D" instead of just "Minimoog".
by adamstan
Thu Jun 09, 2016 5:30 pm
Forum: General Synthesizers
Topic: My polysynth is finally finished :D
Replies: 179
Views: 40563

Re: My polysynth is finally finished :D

Manual tuning routine:

(to be replaced with autotune on next CV board revision)
by adamstan
Thu Jun 09, 2016 12:30 pm
Forum: General Synthesizers
Topic: My polysynth is finally finished :D
Replies: 179
Views: 40563

Re: My polysynth is finally finished :D

Did you just come up with the idea yourself I'm not sure ;-) Certainly haven't seen it used that way in any synthesizer. However, it might have been suggested in DAC08 family datasheet - one of the applications mentioned was "attenuator". Obviously nobody did it in the '80s, because then DACs were ...
by adamstan
Wed Jun 08, 2016 11:12 am
Forum: General Synthesizers
Topic: My polysynth is finally finished :D
Replies: 179
Views: 40563

Re: My polysynth is finally finished :D

All you need to do now is mass-produce it ! :D This one - probably not. However I'm working on 6 voice desktop module, that is intended for production: http://www.vintagesynth.com/forum/viewtopic.php?f=1&t=80452 This project features OTA State-variable multimode VCF, but if it turns out good, I pro...
by adamstan
Tue Jun 07, 2016 10:42 pm
Forum: General Synthesizers
Topic: My polysynth is finally finished :D
Replies: 179
Views: 40563

Re: My polysynth is finally finished :D

I've finally managed to record proper video demo = after 8 years :D As we say - "better late, than never" :-)

by adamstan
Wed May 25, 2016 10:09 am
Forum: General Synthesizers
Topic: Simmons SDSV demo video
Replies: 3
Views: 943

Re: Simmons SDSV demo video

Yeah, it's probably my favourite electronic drum sound. Have to build something similar for myself - I'm thinking about doing a drum machine with five SDS-based voices (kick, snare, three toms), some kind of hihat module, 808-ish clap and cowbell - and 32-step pattern sequencer. Add trigger ins and ...
by adamstan
Fri May 20, 2016 7:33 am
Forum: General Synthesizers
Topic: New DIY project - TOS polysynth :-)
Replies: 42
Views: 10080

Re: New DIY project - TOS polysynth :-)

Small update - I made "overlay" board for dividers, so now i can distribute signals from oscillators to octave sub-boards with convenient ribbon cables. I've also added transistors for return path to HFO - they are needed to convert TTL level from divider to 12V expected by PLL loop on HFO board. ht...
by adamstan
Fri May 20, 2016 7:16 am
Forum: General Synthesizers
Topic: Moog model D reissue
Replies: 166
Views: 32381

Re: Mood model D reissue

In the hands-on demo I watched on synthtopia, the Moog employee was saying it has CV-patchable aftertouch routing. That, friends, is badass! Yes, but based on the video, there's no place to patch "Aftertouch" to "Modulation Amount". So, if true, you cannot do the most common aftertouch effect...you...
by adamstan
Thu May 19, 2016 4:35 pm
Forum: General Synthesizers
Topic: Moog model D reissue
Replies: 166
Views: 32381

Re: Mood model D reissue

You mean it responds to every second key you press? ;-)
by adamstan
Sat May 14, 2016 6:17 am
Forum: HELP!
Topic: FIXED Simmons SDSV Tom Tom module noise not working
Replies: 13
Views: 2016

Re: FIXED Simmons SDSV Tom Tom module noise not working

WhinyLittleRunt wrote: I was getting no signal on 4 and 7.
These are power connections for the chip - V- and V+. :lol: Cool that you have that bad boy running again :-) So it seems, that the board is double-sided, but the holes aren't plated - pins/leads have to be soldered separately on both sides.
by adamstan
Fri May 13, 2016 10:57 pm
Forum: HELP!
Topic: FIXED Simmons SDSV Tom Tom module noise not working
Replies: 13
Views: 2016

Re: Simmons SDSV Tom Tom module noise not working

Is this just the way they made the drawing
Yes :-)