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Quadrovibe questions

Started by gmr1, July 20, 2011, 09:59:29 AM

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gmr1

Built one of these up last night. While I do like it, it could still use some tweaking. Some questions I ran into are below. Perhaps Brian, or anyone else can chime in.

In the build document, it mentions socketing R11/12 for tweaking. It also mentions the value of these resistors is 2K2. It's actually R16 and R17 that are the 2K2 resistors. Brians build picture gutshot also shows that 16 and 17 are socketed, and not 11 and 12 as mentioned in the notes. This is an error, and it should be R16/17, correct?

I used a second switch for vibe/trem. When switching from vibe to trem, it gets quiet for a second or two, and then returns to full volume. Anything I can do about this, or should this switch be better left to a toggle, and not for switching on the fly?

Thanks! - greg

madbean

Yep, I need to correct the resistors to R17, 18. Thanks! Also, where it mentions the rate LED, it should say R19 and not R14.

The delay in volume in switching between the the two is due to the change of values in the emitter resistor of Q2. In order to balance the relative volume between the two options, T1 was added so that additional gain could be applied to the transistor in tremolo mode. The only thing that comes to mind to eliminate that for on the fly switching is maybe try a bypass cap. Try sticking a 1uF electrolytic between S1 and S3 on your switch, with the negative lead towards S3. Looking at the wiring diagram, that's the two outside lugs on the bottom row of the switch. You might have to experiment with different values to see if it works.

GhostofJohnToad

R17 & R18 or R16 & R17? Based on the gutshot, and 2k2 values mentioned,  I assume you meant r16 & r17 madbean.  Just in the process of building my vibe right now.  :)

Jamiroking

#3
Hooking up the leds, I was wondering If it was possible to have the synced pulse going on even while the pedal is in bypass. Orally, I'd like two leds, switchable to indicate which effect is chosen, always pulsing with the lamp speed and an additional typical indicator led. Is this possible

EDIT:

Nevermind! Took a double take at the schem and figured it out! duh!