My Mini Moog Voyager. Click to go to my web site...

Wednesday, March 30, 2011

5U Format Synthasystem VCF by Tony

Tony has finished a 5U format Synthasystem VCF. Nicely done Tony!

Monday, March 28, 2011

Last Details

I've been spending the last while dealing with the details. I went through all the schematics several times making sure the notes were complete and that I had included all the information from the original schematics. I double checked all the PCB component drawings to make sure I could see all the component names and values. I went through the web site and updated all the files, completed the last modules pages (like the Selective Inverter), and fine tuned the calibration procedures for the VCOs and a couple of others.

The only thing really left is the Duophonic Keyboard.

Since I have now finished at least one of all of Nyle's original modules, I started to fill out the racks. I built two more VCO Type A's this weekend. Amazingly enough, they worked first time. I'm going to do a video on calibrating these things as soon as I get my latest toy, an Agilent 200X series oscilloscope. I'm getting the 4 channel, 70MHz version. It is way overkill, but I've been wanting a four channel scope and this one has a huge display.

Agilent 2004X Four Channel 70 MHz


Friday, March 18, 2011


For perspective, here is an original, semi-custom, late model Steiner-Parker Synthasystem. Note there are some custom modules in this that Nyle didn't recognize. In the bottom row, right hand cabinet is a frequency counter. Nyle said it didn't really work that well. There are also a couple of modules which look like multiples, one with some attenuators. SDIY then, too I guess. Why not?

You'll also see that the physical size of these modules are very close to the euro-rack panels I've laid out. I really tried to keep the layouts faithful to these, but in an effort to make the widths even multiples of a euro-rack, etc. I had to compromise on some of the smaller width modules. But, I think a pretty faithful reproduction of the original...

The best compliment Nyle paid me was when he saw some of the first prototype modules racked, he thought he was looking at one of his original systems. That made me really happy.

Some progress photos

Here are some quick photos of my Synthasystem.


  • Frequency Divider
  • Sequencer
  • VCO A
  • VCO B Square/Saw
  • VC Trigger Generator
  • VCF
  • Tuner Monitor
  • Triple EG
  • VCA/Mixer
  • Peak Selector
  • Sample and Hold
  • Trigger Converter
  • 2 "Multipliers" (what Nyle called multiples)
  • Ring Modulator
  • Phase Shifter
  • Voltage Processor/Mixer (VPM)
  • Dual Voltage Follower (Slew)
  • Power Access Module
Still to do:
  • At least 2 more VCOs. I'm going to build one with all discrete parts to try to have a real vintage build
  • Another VCO B with Sine/Triangle
  • Two more VCFs
  • One or two more VCAs
  • One more VPM
  • Noise generator
  • Input Amplifier
  • Selective Inverter
  • One more Phase Shifter
  • One or two more EGs
  • One or two more Voltage Followers
Here are some photos so far:

Thursday, March 17, 2011

Long time

Long time, sorry.

I'm busy building my own production modules. I have many of them completed like the Frequency Divider, One VCO Type A with high frequency tracking compensation (two more at least to follow), Phase Shifter, Ring Modulator, etc.

I also broke down and bought a Tinisizer, This is truly a unique and cool synthesizer. "Analogue Tommy" outdid himself with this one. I have serial number 14, so I think it is fair to say it is a "boutique" synthesizer. I'll publish a more complete review with thoughts after I've had more time to play with it. So far, however, I love it.

More small updates to the web site, so if you purchased a PCB from me, please check to see if your module is affected. Nothing big, just clarifying some construction notes, BOMs, and a couple of component value changes.

Thanks for reading.

Monday, March 7, 2011


There's not too much to say right now. I'm working on building the "production" modules for my own system. I have all the panels, PCBs, etc. now and I'm just building. I'm thinking in the next month or so I'll have it all assembled.

In the interim, I'm building cables, multiples, replacing the keybed in my Moog Voyager, trying to make time to play around with my just received Zeroscillator, and learning software. In other words, having a lot of fun.

I will re-visit the Steiner Duophonic keyboard after I've got more of the final modules built and working. I have the major pieces to do the interface between the matrixed keybed and the Steiner circuit, I just need to decide the form factor for the PCB and other electronics.