Magnavibe.

[Devius]

I have this delightful little marvel penetrating my breadboard. Sounds awesome.
However, when I crank ye ol' depth knob full counterclockwise, the led lights right up, to the point of always on. No pulse, no magic, it's killing my buzz.
would I replace the resistor from v+ with something higher, or is it a bit more complex-icated than that?

[deadastronaut]

that's probably how i'd attack it...but first try another led in series/para, if it works you've got a nice indicator led too..


ive been looking at this little circuit to breadboard too...just waiting for space..

[haveyouseenhim]

that's probably how i'd attack it...but first try another led in series/para, if it works you've got a nice indicator led too..


ive been looking at this little circuit to breadboard too...just waiting for space..

I have built several and that's how I do it. Just wire it in parallel and have it go to the third pole of the stomp switch for bypass and rate indication.

But I don't think that's his problem. I would just put maybe a 1K resistor in series with the depth pot


What layout are you using?

EDIT   I just re read that it's on your breadboard. I highly recommend nocentelli's vero layout. Has never failed me.

[midwayfair]

Phase shift oscillators have a habit of conking out when too much voltage/current is allowed to pass. The minimum resistance I can get to reliably work in the Magnavibe even with a superbright indicator LED is 1.8K. I just use 2.2K because any lower and the depth will affect the speed (and also be ironically less deep).

Note that there's also a minimum resistance on the speed? Same idea.

[deadastronaut]

@jon, interesting, i'll have to try this little circuit out..cheers man. 

[Devius]

I already tried the led to no avail however I will probably end up using it as a rate indicator.
I'll muck around with the resistance in that area and see whats what.

that's probably how i'd attack it...but first try another led in series/para, if it works you've got a nice indicator led too..


ive been looking at this little circuit to breadboard too...just waiting for space..

I have built several and that's how I do it. Just wire it in parallel and have it go to the third pole of the stomp switch for bypass and rate indication.

But I don't think that's his problem. I would just put maybe a 1K resistor in series with the depth pot


What layout are you using?

EDIT   I just re read that it's on your breadboard. I highly recommend nocentelli's vero layout. Has never failed me.

I've gotten into the habit of making my own layouts. So far so good.

[duck_arse]

I'm playing with phase shift oscs again, and I found the 2 transistor circuit used in the vibecaster provides a MUCH sine-ier signal than the single transistor version. although at slightly less output level, which may not be a led driving problem. as you're on the breadboard, you could give it a go.

I can't see a circuit for the magnavibe, so I'm not sure your osc circuit.

[nocentelli]

I've always used a handrolled optocoupler, and find it's fairly easy to adjust the depth by fiddling with the proximity and orientation of the the LED/LDR pair: However, most people complain that they're not getting ENOUGH depth, not too much.

[Devius]

I stuck a 1k resistor in series after the led, seems to work fine. All I'm after is getting an even taper from the pots so they don't "jump" to lightspeed.

I'm playing with phase shift oscs again, and I found the 2 transistor circuit used in the vibecaster provides a MUCH sine-ier signal than the single transistor version. although at slightly less output level, which may not be a led driving problem. as you're on the breadboard, you could give it a go.

I can't see a circuit for the magnavibe, so I'm not sure your osc circuit.

I googled magnavibe and found the schem. I'll check out the vibecaster.
I'm also working on the vicovibe... which sounds like a trem. I like these low-part sweet effects.

[deadastronaut]

yeah that vico vibe is a tremolo, going by the videos ive heard..

be nice to get both the vico and magnavibe in 1 pedal...