tremulus lune question

[PurpleTheory]

I was going to take a shot at building a tremulus lune (www.commondsound.com). I'm having a little trouble understanding the layout. i have a bunch of vactrols so i figure i'll use one instead of the cds and leds if possible. on the layout, i'm assuming that left of the cds is the led that shines on the cds? and what does the led in the lower right do? are they both supposed to shine on the cds? if that's the case, if i want to use a vactrol, will i have to to use something with 2 leds in it, like a VTL5C3/2?

Thanks for all the times you guys have helped me out,
matt

[RickL]

The second LED is a effect on/trem speed indicator.

A Vactrol should work fine for the LED/LDR combo but why not try if with discrete components first if you have them? I'm pretty sure an LED and a CdS cell are cheaper than a Vactrol. I've built both the Tremulus Lune and the Paneur (stereo tremulus) with unselected LDRs and they both worked fine from the start.

[PurpleTheory]

cool, thanks for clarifying that for me. as for the cds i found some that i bought at radioshack years ago, but no longer have the specs on them, do you know how i can tell if they would be suitable for the project? also, what color of led did you use for yours, does the color matter?

thanks,
matt

[RickL]

Use sockets for the connections and try it. I always use sockets for Vactrols and LED/LDR combos anyway since I'm worried about overheating the components. Either buy the strips of break-off sockets from Steve at Small Bear (or locally if you can find them) or cut up op amp sockets with machined contacts. I haven't had much luck cutting up sockets with leaf type contacts but you might have better luck.

I used red LEDs in mine but it's worth experimenting with green and yellow (easy if you use sockets  :wink:  ).

[Fret Wire]

$.59 cents for a VTL5C2 is pretty cheap.
http://www.bgmicro.com/prodinfo.asp?sid=0459386574074074691664869&prodid=ICSVTL5C2&page=1&cri=ICSVTL5C2&stype=3&time_out=44:49