AM1034 Dual ADSR

AM1034 Module

Overview This is a Dual Envelope Generator module that uses circuits from the E-mu Systems Modular Transient Generator. I have a few new SSM2056 chips that Ron Dow gave me back in 2002 and they form the basis of this module. The advantage over the standard ARP design is that envelope times are longer (1ms – 10s).

AM1034 Module My design uses the same schematic in the 2350 Transient Generator but modified so that it can use the SSM2056 chip, which has a lower 0V to +5V output. The delay circuit is based on a CA3046 chip and some CMOS chips. The SSM2056 output is boosted to 10V and available inverted and non-inverted. The potentiometers are metal can Vishay 100K linear and mount to a separate panel PCB that is connected to the main PCB by 10 way ribbon cables.  The module has the following front panel controls for each Envelope Generator:

  • Delay
  • Attack
  • Initial Decay
  • Sustain Level
  • Final Decay
  • Toggle switch for Multiple or Single Trigger
  • Red LED Indicator Lamp for Gate On
  • Manual Gate Push Button

There 10x 3.5mm jack sockets mounted on the rear the panel, for each Envelope Generator we have:

  • Gate
  • Trigger
  • Gate 5V
  • Inverted Output
  • Normal Output

AM1034 PCB

Module Build The PCB’s were laid out in March 2016 and a single set ordered and built at Easter 2016. The design took a bit of work to sort out the control voltages from the pots to the 2056 chip, in the end +5V was the right power rail for them, and a different resistor value for attack than decay and release.

After some hard work both channels worked perfectly, with 10 second stage timings. I changed the potentiometer PCB to provide a wider spacing as in the 1033 and built up the final module with a nicely designed ARP replica panel in mid April 2016.

2019 Update The lettering on the panel quickly rubbed off due to manufacturing defects, and the module was stored. I plan to buy a new panel in 2020 and fit the module into my Tolex cabinet which holds ten modules. The Dual ADSR works well but I may replace the PCB with a version that uses discrete logic and is voltage controlled, to release the SSM chips.

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