Chankgeez wrote:Yeah, improvements are almost always good. I've played numerous revisions of some circuits and most times the changes come at a sacrifice to some of the things I really liked on earlier versions. So, proceed with caution!
There will be an updated Monobius in the tourbox, so you'll be able to compare them directly. I'm happy to update any/all Monobius already out in the wild, should it be desired, this would be free of charge (but I'd request interested parties to carry shipping both ways since I'll be covering parts & labor), I can also provide details if anyone wants to mod it themselves.
Main changes have been upgrading to a 4PDT footswitch so I can snub the on board oscillator when it's in bypass (since shorting both input and output of the circuit to ground in bypass was not completely eliminating bleed from the oscillator), and loosening up bandwidth constraints on the final summing section and a carrier section. The latter bit sounds like turning up the presence/reducing negative feedback, and to my ears it levels up the two diode modes that were quieter than the other, evening things. It would be easy enough to switch in and out.
Carrier bleed is part oscillation up the power rails (I'll look into snubbing this on a future revision) and plain old balancing issue, and it's pretty easy to push it over with the gains & levels on tap. I did hand match all the diodes, but they are silicon - which makes a 0.1% tolerance twice as high as germanium. I do have a diode matching rig in the works that should match them quite tightly, but I need to refine the design a bit. Then there's sloppy tolerances from the transformer manufacturer, I'm dreaming about winding my own transformers, and these would be a good place to start since it does not need a high pot test for safety (like a mains or tube output would). That too is sort of a pipe dream at the moment (AKA low priority), but I'm thinking about it..
I find it is easier to get close to null on carrier bleed when both input and carrier levels are in the noonish range, and of course lower oscillator pitch ranges are easier to bury. If the bleed bothers you and I resolve it through a future rev (that does not depart from the sound qualities you enjoy), I'm happy to trade the boards out.