Big Monk
Well-known member
I've been working here and there on a design for a revised and slightly re-imagined UniVibe circuit.
@Chuck D. Bones has given me some design elements, with a reworked Opamp front end in particular along with several other improvements, based on talks we have had.
My plan is to do some R&D and testing using the E-Vibe Mini as a platform. I have a pretty good working cross reference sheet started so that I can use the E-Vibe Mini parts list and the Big E-Vibe schematic together.
While I can't do the Opamp front end on the E-Vibe Mini board, I can implement pretty much all the other circuit mods involved with minimal tweaking. The stuff I plan on doing are as follows:
1.) Substitute the 2N5088s for true MPSA13 Darlingtons in all stages and re-bias the stages accordingly
2.) Tweak the phase mix resistors for perfect balance
3.) Ditch the charge pump circuit and inject 24 vDC directly to the regulator
4.) Increase the Series LDR caps to 10 uf to increase phase notch presence/depth
5.) Add a 330 ohm/1W resistor in series with the lamp for overcurrent protection and ease stress on bulb and bulb driver Darlington
6.) Enhance the upper and lower speed limits. the 24 vDC powering the LFO along with these changes will vastly improve slow speed depth
7.) Use the externally adjustable 3362P trims for Bias and Gain
8.) Try out a "Cancel" switch for access to the preamp by itself
This will be an effective prototype for what I'm calling the "MonkVibe", which will have the opamp preamp and a faux "Cancel" switch that routes the I/O through a duplicate preamp instead of standard "Cancel" mode.
@Chuck D. Bones has given me some design elements, with a reworked Opamp front end in particular along with several other improvements, based on talks we have had.
My plan is to do some R&D and testing using the E-Vibe Mini as a platform. I have a pretty good working cross reference sheet started so that I can use the E-Vibe Mini parts list and the Big E-Vibe schematic together.
While I can't do the Opamp front end on the E-Vibe Mini board, I can implement pretty much all the other circuit mods involved with minimal tweaking. The stuff I plan on doing are as follows:
1.) Substitute the 2N5088s for true MPSA13 Darlingtons in all stages and re-bias the stages accordingly
2.) Tweak the phase mix resistors for perfect balance
3.) Ditch the charge pump circuit and inject 24 vDC directly to the regulator
4.) Increase the Series LDR caps to 10 uf to increase phase notch presence/depth
5.) Add a 330 ohm/1W resistor in series with the lamp for overcurrent protection and ease stress on bulb and bulb driver Darlington
6.) Enhance the upper and lower speed limits. the 24 vDC powering the LFO along with these changes will vastly improve slow speed depth
7.) Use the externally adjustable 3362P trims for Bias and Gain
8.) Try out a "Cancel" switch for access to the preamp by itself
This will be an effective prototype for what I'm calling the "MonkVibe", which will have the opamp preamp and a faux "Cancel" switch that routes the I/O through a duplicate preamp instead of standard "Cancel" mode.