Can I run the EA Trem at 18V?

[powerplayj]

I want to place it in the same enclosure as my Vibe and was wandering if the stock circuit will run on 18V (all caps are 25V or higher)?  If not, I assume I will have to play with the R2 and R4 if these are voltage dividers.  What replacement values would I need here?



Thanks,

Jason

[sfx1999]

I think that may be a little too high. The LED would blow for sure, you would need to increase its resistor value.

You may want to consider leaching the power off of the 7815 on your Neovibe. If you did that, you should probably not use a 78L15, though.

If you want to be damn sure it will work, use a 7809 from the 18V power, provided that it is DC.

[powerplayj]

I assume that is a 9V regulator?

I had 9V in with a charge pump for the Neovibe but it seems to run better from the 18V main supply rather than the ~17V supplied by the pump. 

[sfx1999]

I mean you can connect the 18V supply to a 9V regulator, as long as that 18V supply is DC. The 78L09 should work fine for this.

[momo]

Hey guys, I just finished my Neovibe and im now working on a FuzzFace, im using funky enclosures and the 2 fit together as a puzzle if you will. Now using a Univibe and FFace go well along, so im thinking also to actually take the 18v from the Neovibe and regulating it for my FuzzFace. The question is that my FFace is positive ground.
So if I put a regulator lets say after the diode bridge on the univibe, since the FFace is positive ground, is it just a matter of inversing the supply wires from the regulator to the FFace?
It would be great to power the 2 from my 18v source. Im using the 100ma 78L15,...is that enough for the 2 effects?

I dont want to highjack....my questions seem to be going in the same direction....
thanks!

[Processaurus]

Its safe to at least try it at 18v.  Nothing will break, not even the LED (if you use that 4.7K resistor, 18v - the LED voltage drop = 16.6v.  That through a 4.7K resistor =3.5mA, much less than the 20mA most LEDs are rated for), which will just be brighter.  Running it at higher voltage gives the benefit of more headroom, which this circuit needs badly.  The LFO section might act different (bigger output) but you can just turn the depth down.

Hey, you could sync the LFO of the vibe and tremolo by running the vibe's LFO through a coupling cap to the depth pot on the EA.  Might be an interesting, leslie like sound.

Momo, it'll short out your supply when you connect your grounds together.  I'd use a charge pump chip to get the negative voltage.

[powerplayj]

Its safe to at least try it at 18v.  Nothing will break, not even the LED (if you use that 4.7K resistor, 18v - the LED voltage drop = 16.6v.  That through a 4.7K resistor =3.5mA, much less than the 20mA most LEDs are rated for), which will just be brighter.  Running it at higher voltage gives the benefit of more headroom, which this circuit needs badly.  The LFO section might act different (bigger output) but you can just turn the depth down.

Hey, you could sync the LFO of the vibe and tremolo by running the vibe's LFO through a coupling cap to the depth pot on the EA.  Might be an interesting, leslie like sound.

Momo, it'll short out your supply when you connect your grounds together.  I'd use a charge pump chip to get the negative voltage.

.....Tried it and it was very gated/choppy.  I assume the I would need to change the resistor values near the input such that with 18V the collector sees half the voltage as it would with a 9V V+.