PPG 300 Modular

Overview Wolfgang Palm developed the 300 series modules as a replacement for his original Moog Modular like 100 series in 1976. He re-used some of the circuits and added new front panel designs. The 300 series consisted of 12 modules, cabinets and keyboards.

Klaus added a full set of PPG 300 analog modules and two PPG analog sequencers in 1976, and placed them on top of the Big Moog, where the ARP 2600 and EMS 8 Octave Bank usually lived. The PPG setup replaced the Synthanorma SQ312 analog sequencer, and his ARP 2600 in the live rig.

This 300 modular system probably cost £15,000 in todays money (DM 8000 at the time), the 314 sequencer was particularly expensive. He kept the PPG Modular setup until he moved onto digital synths in the early 1980’s, and it seems to have been sold quickly, whilst the Big Moog survived in his studio until 1996.

The Moog IIIP only has a few filters, and you can see the 904C set to Band Reject, so I am sure Klaus enjoyed the additional PPG sounds. He expanded his live rig into the late 1970’s with two Minimoog’s and a Multi Moog, so he loved the Moog filter. In 1980 Klaus swapped out the 991 and 994 and put two PPG 303 VCF/VCA modules into his Big Moog.

The left hand rack contains two sets of 314 sequencers and 313 analog switches. The right hand rack contains a 3x VCO mono synth;

  • 301 VCO x3
  • 303 VCF & VCA
  • 315 Dual Ring Modulator
  • 316 Random Voltage Generator
  • 308 Dual DADSR
  • 311 Power Supply

Live concert pictures show the VCO, VCA and DASDR patched but the 315 and 316 not used. Klaus clearly choosing more traditional analog sounds rather than using the more experimental noise and ring mod sounds available. The dual sequencer setup was used across the whole Moog and PPG system, giving Klaus a total of 4x 8 -24 step sequencers. Klaus also added two PPG 303 modules into his Moog Modular around 1979.

Recreation By mid 2021 I had successfully replicated the Big Moog using Behringer and AMSynths modules, and recreated the EMS 8 Octave Filter Bank. I began to research whether the PPG 300 modules could be replicated. There are no official schematics and they were often hand drawn, Wolfgang destroyed his archives in around 1999.

My recreation process is therefore based on tracing out the schematics from pictures of the PCB’s and making some assumptions on components that were used and available in 1976.

  • PPG 301 This is a 3046 based VCO with 4 wave shapes, PWM and Sync.
  • PPG 303 This was the first circuit I replicated and it is a copy of the Mini-moog VCF with the addition of a VCA – which I have assumed is a 3080 OTA.
  • PPG308 This (and the 307) look like traditional 555 based ADSR’s with a delay circuit in front, possibly using a 3046.
  • PPG313 This is a rather clever analog switch based on a 4011 and two 4017 chips. Each step can be active for an additional 2, 3, 4 or 8 clock periods, before moving onto the next step
  • PPG314 This is an 3×8 step analog sequencer that uses the 4017 decade counter chip, and is very similar to the Roland 717.
  • PPG 315 This circuit is harder to recreate but I think an 3080 is used for both the 4 and 2 quadrant multipliers.
  • PPG 316 I have no pictures of the PCB’s so can only assume its a traditional transistor noise source and S&H.
  • PPG317 Although Klaus did not have this module I have recreated it based on the VCF in the 303.

I decided to replicate a small PPG 300 setup with 3x 301, 303, 308 and 315 modules. These live in a Doepfer 84HP Euro Rack. I have also added a 317 in my main Moog Modular and a 313/314 combination.

Copyright AMSynths 2019