Baja Trembulator schematic, board layout and circuit board

ebuprofen · Post by **ebuprofen** » 16 Jan 2013, 07:27

omg, galmar, thanks a lot, one coupling cap didn't make any difference, but two of them (the second one is between DEPTH pot and inverting input of the second half of TL062) made the pedal work as it should, thanks again, you saved my ass

moderators, please remove two schematics that I posted above, as they are a bit wrong.

galmar · Post by **galmar** » 16 Jan 2013, 10:45

ebuprofen wrote:omg, galmar, thanks a lot, one coupling cap didn't make any difference, but two of them (the second one is between DEPTH pot and inverting input of the second half of TL062) made the pedal work as it should, thanks again, you saved my ass

moderators, please remove two schematics that I posted above, as they are a bit wrong.

Exactly! I hadn't noticed that you did not have ac coupling in that stage, too. As you can deduce, the same principle applies there and a cap is needed too!
Glad to hear it worked!

Mbas974 · Post by **Mbas974** » 25 Dec 2013, 21:29

Hi, great pedals Mr Baja !!

I'd like to implement a mode I see on one commercial pedal but I have no idea how to...
Controlling the frequency of light time and dark time of the oscillator (as per image).

Thanks in advance.

mozwell · Post by **mozwell** » 14 Sep 2015, 06:15

Hi Baja
Built this one up for our guitarist, its very nice. Thanks for the project.

I added the switch across the calibration pot to go from smooth trem to harsh trem.
One thing I found, and I want to point it out here in case others have the same problem, is the Vactrol. I used a Siliconix NSL-32SR3 as I had a few on hand. I couldn't get the smooth trem. I had to order in & use a VTL5C1 as per your diagram.
So if you cant get it to be smooth, try putting a proper VTL5C1 in there.
Love the trem & more power to your soldering iron !

The siliconix vactrol must be really hi gain which caused my problem.
VTL5C1 at 10mA led current, output is 500ohm & at 1mA led current output is 10k
NSL-32SR3 at 10mA led current, output is 80ohm & at 1mA led current output is 300 ohm, even at 0.1mA output is 2k (but dark resistance is 25M ohm similar to VTL5C1)

Chugs · Post by **Chugs** » 29 Sep 2017, 08:59

I presume the 100K resistor to ground before the Depth controls is redundant when used with the added output buffer version?

Presumably it was acting as a pulldown resistor on the output in the original version.

Post by **modman** » 04 Jan 2018, 22:20

I updated the files as attachments to the first post:
viewtopic.php?f=13&t=300&p=2720#p2720

taxfree · Post by **taxfree** » 29 Jan 2020, 14:52

I built my Trembulator and wanted help with 2 questions:
1 - Is it possible to change the waveform?
2 - I have the impression that the sound is poorly defined, especially on the E, B and G strings, as if there was "cotton" in the sound. It's not about adding a drive. It is as if the tremolo makes the sound muffled, contained. (I don't know if I'm using the right words).

Baja Trembulator schematic, board layout and circuit board [documentation]