Anyone built a Magnus Modulus?

[maysink]

Got a MM board from brian some months ago off the BYOC forum and finally got the beast wired up. Once I realized nothing worked due to unpopulated IC sockets (...) it came to life. Mostly.

The bypass/boost works (lots of boost on tap), the delay works as does the chorus modulation but the tremolo is so faint I can only hear it when certain knobs are maxed out. The chorus modulation is far more pronounced than the tremolo but not as severe as I've heard on demos.

I do *not* have the recommended opamp but have tried a 4558, tl072, tl082 & a burr brown opa-whatever. The '82 & 4558 seemed to make the tremolo a tad more pronounced. Any thoughts? I'll be ordering some NE5532 opamps some day and see what changes that brings.

The 4 knobs & stomp on the left are trem. Middle 3 knobs, toggle & middle stomp is delay. Left most knob is gain and left stomp is bypass. The LED under the gain is the modulation blinker. Housed in a box like EHX uses for the cathedral and so on.

[madbean]

IIRC, the trem portion of the circuit utilizes a either a j201 or 2n3904 for the effect. Maybe that's the problem area 

[maysink]

I'm socketing the JFET to sub some work-alikes. RE: opamp #2; was I making the difference up or is that opamp not involved in the trem section? Anyone got a suggestion what I should read/research to learn myself this info???

as an aside... I'm at that point where I can make a pedal from vague and/or detailed instructions (kits vs. vero/PCD-only) but the academia/tech of pedals is just beyond my grasp/effort.

whoa. this thread took a turn!

[Hyatt]

I'm in the same boat maysink.  We're more assemblers than designers. 

But just wanted to say after looking at some vids, that is a rad pedal.  As for your problem, I just built a tremolo and it was also very faint at first.  This particular one had 3 trimpots, 1 for the led, 1 for the optocoupler and 1 for volume.   They all had to be tweaked for it to sound good.  From the looks of your pics I dont see an opto or trimpots but you may not have enough power going to the lune part of the board.  Don't know if that helps but if it is a power thing then maybe you should try to get the op amp meant for it. 

I built this envelope filter and I forgot to order the op amp so just tried some leftovers I had.  Didn't work, couldnt figure out why, finally got the right op amp, popped it in the socket and it was alive.

Sorry I can't be of more help but if you really want to get to the bottom of this, just email whoever designed the pedal.