I impulse bought a Behringer 2600 a month or so back after discovering Sam’s Youtube channel and got bitten by the analogue/modular bug.
I can already do digital electronics including PCBs etc so I figured I can learn the analogue stuff and save some £££ in the process.
And the Transcendent 2000 looks like an interesting starting place, given the schematics are easily available. Original magazine articles:
So, here’s my breadboarded slow oscillator. Layout pretty much matches the schematic.
I was going to post schematics and scope traces here but I’m only allowed one image
But the period is running from 50ms to 15s which matches the design (0.06 to 20Hz) and the waveforms and peak-to-peak values look correct for the triangle, sine and square waves.
So I’m feeling rather chuffed. I’d appreciate feedback if I’ve made any mistakes.
Connecting it to the 2600 I notice that the outputs need to be buffered, especially at low frequencies.
I figure if I want to make this into a module then I’ll need a couple of enhancements:
- The square wave outputs need to be buffered.
- The sine wave output needs to be amplified to 10V (or should that 12V?).
- And I’m tempted to make the sine output bypassable so I can still use a ‘true’ T2000 value (or would it make more sense to add extra attenuation the VCO input?
And on the input side I’d like to be able to add voltage control. I’m guessing that would be an extra input to IC32 pin 2? I’m watching the Moritz Klein stuff on YouTube and I think he’s covered that in the VCO build using an NPN transistor. I’ll have to research but I’ll happily take guidance on that.