A post long in the coming, I’m announcing that all the electronic work is DONE on my Pharmasonic System 700 clone! I purchased a Hexinverter Mutant Brain to function as the MIDI-to-CV input for the synth and also picked up a black faceplate for the 4MS SISM so it wall match the rest of the …
Tag Archives: Rockstar
The New Case
I’ve just slapped together the final home for the System 700. Having built a few of these already, I feel like my craftsmanship in case building is slightly improving. I bought a cheap table saw and table router to assist with the task, resulting in some nice, rounded edges on this case. Using mounting templates …
The Big Sprint
I spent many hours yesterday checking components, replacing incorrect bits, testing and calibrating modules, but ended up at the end of this marathon session with the following additional fully working and calibrated modules: VCA 1 VCA 2 VCO 1 VCO 3 703C multimode filter LFO 2 Currently, all that remains is: Replacing a resistor on …
LFO 1 Troubleshooting continues and a storebought module digression
Alright, I know all posts so far have been about building my SYS-700 modules, but I wanted to take a moment to share my thoughts about some of the storebought modules that have made their ways into my racks. But first an update on LFO 1’s troubleshooting work. LFO 1 turned out to have a …
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Troubleshooting Continues!
I’m elbow-deep in troubleshooting the 1st of the 2 LFO’s. It is oscillating fine, and is even outputting the various waveforms that it should be capable of with gusto. But the Frequency pot isn’t adjusting the frequency. Fortunately, the generous exports at Muffwiggler are assisting. Additionally, the IC’s for the Phase Shifter arrived from China, …
ADSR and LFO’s
I was able to test the ADSR this morning before work, and was able to fairly quickly find the issue when it wasn’t working. In reviewing the board, I found a single 100k resistor that was supposed to be a 100 ohm resistor. Replacing this component with the correct value got things working! This officially …
A Rush and a Push …
I returned from a 6 day trip to Arizona to find the replacement IC’s had arrived, and quickly worked on several ‘problem’ modules to install these and test them out. I was able to successfully test the Noise/Ring Mod and the 2 VCA’s. I was also able to add IC’s back to the already-tested Mixer …
One more red press-button closer …
Yet another order of straggling parts have arrived, this time bearing a red push-button for the ADSR that I had overlooked. The only exciting thing here is that it is the only one of its kind in the project– all other controls are either pots, rotary switches, or toggle switches of some sort. I must …
Today’s Lesson: Don’t order IC’s from China
After some very helpful assistance from some of the folks on the Muffwiggler forum (and Pharmasonic), I’ve determined that all the LM301 opamps I purchased off eBay are bad. I found 3 opamps that I had ordered for the S&H and Mixer units in my 1st round of work on this project that LM301 compatible, …
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The First Troubleshooting Success
After a few days of nagging Pharmasonic and many users of the Muffwiggler forums, I have managed to troubleshoot the 1st of my problematic modules, the 707 Amp/EF/Integrator, and this process has uncovered problems in several of the other modules as well. It turns out the LM301 opamp IC’s that I bought are bad. These …