Tremulus build report, not 100% ok

[mph]

Hello

I've just finished the build of a Tremulus using the Commonsound data. I have redrawn the layout to add the "Aux LFO modulate" mod, and it was soldered on perfboard.

http://commonsound.org/tremulus/tremulusboard.pdf
http://commonsound.org/tremulus/tremulusbig.pdf
http://commonsound.org/tremulus/symmetry.pdf
http://www.commonsound.com/tremulus/killstomp.pdf
http://commonsound.org/tremulus/auxlfo_modulate.pdf

The VTL5C2 worked fine at the first time so I have not tested other optocouplers. And I have replaced the 10K Gain pot with an onboard trimmer which doesn't appears on my perf layout (I have just used the free space on my layout and wired the trimmer with jumpers).
I have used a 2k5 pot for the Aux depth control.

I have carefuly wired all the switches and pots, and triple checked everything... and the diodes for the symm mod are well connected directly to the pot like on the original drawing.

So it is working fine, but I have noticed that this Aux depth pot interacts with the main Speed pot, even when the aux kill stomp bypasses the Aux LFO. When the Aux depth pot is set to maximum is slows the main LFO, and when set to zero it speeds up the main LFO.
Also, when the Aux LFO is engaged, the modulation amplitude is too high for taste (I mean, with the lower Aux depth setting possible, the speed of the main LFO still goes too fast at the top of the sine wave).
I wonder if the purple jumper on my layout is well connected... it was said :" it connects to the other side of the 2K7 resistor"...








If someone can tell me what is wrong... of if it's the normal behaviour what should I change?

Many thanks for your help.

[mph]

Well, I've found the trick with the amplitude of the Aux LFO.
I think the instruction on the commonsound diagram is confusing with this 2K7 resistor (at least for my slow brain).
So I have wired the wire from the CDS to the center pin of a spdt switch, then one wire from the same point as "Speed2", and the other wire from the pin 7 of the 4558 (between 2K7 resistor and the pin 7) to the other pins of this switch.
I find the "stock" wiring very useful, but I also liked a lot the wider range of my bad wiring; so I have kept both via a switch, even if it may appear very subtle, that extra speed boost is great.

Anyway it's a very good tremolo, very creative, and really flexible. I love the speed modulation a lot, that's the reason why I've build it.

Thanks again.

[Slade]

Hey, glad you got it finally working. How does it sounds compared with the demo I make of mine? Could you post a demo of yours?
Congrats! 

[mph]

Thanks Fernando!
that was not so difficult (to tell the truth it is the easiest build I've ever done as I have not made big mistakes on the perf. layout).

I think they sound the same. I've made a little recording for you (sorry it's a line recording, and I use also a pitch shifter).
http://rapidshare.com/files/355125337/tremulus-mph.mp3.html

You'll hear the effect of the switch because when it's on the "mod" position it brings the speed so high that it's near FM or ring effect.
Let me know what you think about it.

I have not your experience in finish, so mine looks also a bit more rough 

[Slade]

Hey, that sounds good.
I think that you're getting the fast speed too fast, the slow speed is almost a 10% of the high speed time, this may be due to a very sensitive LDR. What kind of LED/LDR are you using? VTL5C2? Maybe you should try with a common LDR and testing it for different led colors to fix that, you should have a more "triangular" LFO, iI think. Just a sugestion, if you like it that way don't do anything, it sounds great!

Congrats again for your build, and your finishing looks just great, totally functional, not artistic-painted-exagerated poems like some people do

[mph]

Thanks for the tip.
However, I think I will stick with the VTL5C2, the sound is very good to me like this. And the wave shapes seem to be ok too: the ramp up/down, the sine/tri, or square are quite "regular".
The speed range of the main LFO is really usable for me, but the speed increase created by the Aux LFO modulation is much more interesting with that "range" switch I added. For sure.

Thanks again for your attention!