Category: Tremolo

Trembulator with tap-tempo

I absolutely love the sound of the Baja Trembulator, so what better project to start with when it’s time to try the tap-tempo LFO micro controller?


This is a very basic adaptation; just the signal part of the Trembulator with the standard LFO circuit replaced with the micro controller (and associated components).

I kept all the multipliers, but didn’t really care for the ramp waves, and the triangle wave was very similar to the sine wave, so I decided to keep only the sine- and square wave settings.


I did try this on breadboard, so I’m fairly confident it’ll work. Will update once I’ve built it.

And if you can’t figure out how to compile and program the uC I’ll consider setting a few up and ship out for cost (depending on demand etc.)

Updated: 9 November, 2013 — 00:34

Request: Modified EA Tremolo

This is the modified EA Tremolo circuit as seen on runoffgroove. I believe it’s the same circuit as the BYOC Tremolo.

I decided to lay this one out with the option of using board-mounted pots. If you want to do it this way get the 90 degree 16mm Alpha PCB pots for the “Depth” and “Rate” pots, and get a regular 16mm Alpha solder lug pot for the “Volume”. This should fit nicely in a 1590B. Solder the PCB pots underneath the circuit board (isolate the pot housing with some electrician’s tape or something similar). You’ll need to drill holes 30.48mm / 1.2″ apart for these. And the “Volume” pot can go wherever you feel like it, mounting the board on the two PCB pots should leave enough room underneath there that the volume pot can fit (isolated housing, of course).

Update (18.07.2012): Corrected the pot labeling; there were two depth pots and no rate pot.

Update (07.08.2012): Thanks for verifying the layout, Sam.

Updated: 21 December, 2012 — 22:35

Request: Catalinbread Pareidolia

There have been a few requests for this one. Let me know if you build it and it works. This should fit in a 1590B enclosure.

Update (11.10.2012): Revision 1; changed Q3 and Q6 to 2N5457s.

Update (22.01.2012): Revision 2; I had mistakenly labeled this as requiring 44 cuts while it only needs 43. Thanks to Nocentelli for spotting this.

Update (01.02.2012): Built this one tonight. Had to reorient the depth and rate pots (layout has been updated), but otherwise it worked like a charm.

Update (18.12.2012): Voltage readings from my build as requested:

Power supply: 8.88V

All pots fully CW.

1 +3.75V 0V +8.88V
2 +3.75V +3.75V 0V
3 +3.75V +3.70V +7.46V
4 0V +7.46V
5 +3.72V +3.72V
6 +3.72V +3.72V
7 +3.70V +2.80V
8 +8.88V +3.64V
9 +1.53V
10 +2.82V
11 ~+15mV
12 0V
13 +1.73V
14 +1.73V
15 +0.93V
16 +0.93
Q1 Q2 Q3 Q4 Q5 Q6
D +8.88V +5.71V +1.21V +8.88V +6.02V +1.21V
S +5.71V +0.90V +1.21V +6.02V +0.96V +1.21V
G +4.13V +2.7mV ~+4.3mV +4.21V +2.6mV ~+3.8mV

Update (30.04.2013): Just adding the schematic that I drew based on the trace made by KindaFuzzy over at FSB.


Updated: 30 April, 2013 — 22:46

Request: Tremulus Lune

I don’t know much about this effect other than it’s a tremolo of some sort, and I’m sure it sounds nice. Let me know if you verify the layout.

Update (13.12.2011): Thanks to Mark for verifying the layout as working.

Update (10.02.2012): I finished my build tonight. The internals look a bit messy ’cause I didn’t really feel like being too neat this time; just wanted to get this thing up and running. It’s great fun and a cool project.

Update (15.02.2013): As requested her are working voltages from my own build for debugging purposes:

Battery at 8.97v, all pots fully CW, and speed indicator LED on and flashing quite fast.

U0 U1 U2
1 +7.53V +3.76V ~+4.5-5V
2 0V +3.76V ~+4.8V
3 +8.97V +3.74V ~+4.9V
4 0V 0V
5 +3.74V ~+4.8V
6 +3.76V ~+4.8V
7 +3.69V ~+4.8V
8 +7.54V +7.54V
Updated: 12 April, 2013 — 14:59

Request: Baja Vibrotrem

Here’s a vero layout I just did for the Vibrotrem designed by Bajaman over at I have yet to verify this so let me know if you give it a try and it works.

Update (11.06.2011): Thanks to Jim this is now verified as working.

Update (19.10.2011): Built this one a few days ago and here’s how it turned out (didn’t have any suitable knobs at the moment).

Updated: 21 December, 2012 — 21:09

Baja Trembulator

I’m working on a Baja Trembulator, a tremolo circuit Bajaman from freestompboxes have designed based on the Demeter tremolo. Since I haven’t gotten into etching my own PCBs yet I thought I’d do a vero layout and try it out. I haven’t actually created the circuit yet, but I believe the layout is finished. Just waiting for the parts to arrive in the mail now…

Baja Trembulator vero layout

Update: Built the circuit last night and discovered a mistake on the layout. I had forgotten a cut between C3 and C4, and both pots were reversed, all of which has been corrected now. Layout hereby verified.

Update (07.06.2010): Finished up my Baja Trembulator build yesterday and what a beauty. It sounds great too.

And yes, I accidentally soldered the IC3 socket the wrong way.

Update (20.10.2011): Fixed dead picture links.

Update (10.11.2011): I accidentally attached the wrong layout (wonder how long that one’s been up). This is now fixed, but you may have to hit refresh.

Updated: 21 December, 2012 — 20:40
SabroTone © 2010-2016 Frontier Theme