Tap Tempo Tremolo LFO work for Tri-Vibe too?

[seedlings]

This will be my first foray into building a vibe of any kind. I would like to combine the Tap Tempo Tremolo with the Tri-Vibe, so that the tempo of the Tremolo also controls the Tri-Vibe.  I'd like to omit the Tri-Vibe LFO completely, and instead, connect to the LFO of the Tremolo.  If there will be a significant amount of tweaking, this may not be for me to undertake.  What do you think? Do-able?

CHAD

[samhay]

I might be wrong, but at a guess I would think that while it could be done, if you are think of using Electric Druid's tap tremolo PIC, then there will be quite a bit of work to do between the PIC's output (PWM) and something that will play nice with the tri-vibes OTAs. It should be a lot easier to get this PIC to play nice with an optical vibe like the magnavibe. Also, it seems like the the ROG guys spent a lot of time designing the LFO for the tri-vibe and it kind of seems like a shame not to make use of it.

[seedlings]

I might be wrong, but at a guess I would think that while it could be done, if you are think of using Electric Druid's tap tremolo PIC, then there will be quite a bit of work to do between the PIC's output (PWM) and something that will play nice with the tri-vibes OTAs. It should be a lot easier to get this PIC to play nice with an optical vibe like the magnavibe. Also, it seems like the the ROG guys spent a lot of time designing the LFO for the tri-vibe and it kind of seems like a shame not to make use of it.

Thank you for the response.  Ican build both, it would be nice if the two could share a tap tempo. I don't need all the bells and whistles, just a sine, tap tempo LFO for a vibe and tremolo in one pedal would be cool, but I'm not a designer.

CHAD

[midwayfair]

Not without adding a bunch of stuff after the LFO out. Check the data sheet -- you want the circuit with all the op amps, not the one used in Tyalor's tremolo.

There's probably some way to use a vactrol. I'd think about doing it with a 4/2 set up as a voltage divider with the center leg at the lfo in and outside legs to 0 and 9v, limited in a some way.

And yes, it works with the Magnavibe just fine. But the Magnavibe doesn't have a swirl setting. :-)

[seedlings]

So, to be clear, if the Easy Vibe were fed by the LFO of the Tap Tempo Tremolo, the multipliers and wave shapes would still work?  Would there need to be an additional driver stage for the additional Easy Vibe LEDs?

Thanks for your patience whilst I try to push on to more variety in building.

CHAD

[samhay]

So, to be clear, if the Easy Vibe were fed by the LFO of the Tap Tempo Tremolo, the multipliers and wave shapes would still work?  Would there need to be an additional driver stage for the additional Easy Vibe LEDs?

Thanks for your patience whilst I try to push on to more variety in building.

CHAD

The tap tremolo chip is designed to drive an LED/LDR based tremolo. This works in a broadly similar way, so it should work fine.
I don't know hether you can directly drive 4 LEDs from the PIC, but Jon (midwayfair) has had it drive 2 or 3 in his Cardinal Tremolo, so I would imagine he should be able to tell you.

[midwayfair]

So, to be clear, if the Easy Vibe were fed by the LFO of the Tap Tempo Tremolo, the multipliers and wave shapes would still work?  Would there need to be an additional driver stage for the additional Easy Vibe LEDs?

Thanks for your patience whilst I try to push on to more variety in building.

CHAD

The tap tremolo chip is designed to drive an LED/LDR based tremolo. This works in a broadly similar way, so it should work fine.
I don't know hether you can directly drive 4 LEDs from the PIC, but Jon (midwayfair) has had it drive 2 or 3 in his Cardinal Tremolo, so I would imagine he should be able to tell you.

If you gain up the transistor on the LFO out (in Taylor's version), you can drive about two LEDs in series without a significant loss. There are some limitations, though. If you add too much gain, you get noise, a really unpleasant whine that bleeds into the audio path. You can drive a third or possibly even fourth LED to ground instead of 5v (check the Cardinal thread, the Tap Tempo version shows this). You can get more gain by feeding that signal through the op amp stages shown in the datasheet, but then you're talking about a HUGE circuit in the end, and the tri-vibe is already kinda big.

Of course, you don't NEED more than one LED for most applications. The only reason I needed two LEDs in the Cardinal is because I couldn't get an LDR with high enough resistance swing to work in the circuit I was making, so I had to use two specific vactrols.