Here's a great sounding tremolo circuit from Demeter–the Tremulator. It's an optical trem, using a VTL5C1. That part can be replaced with an LED and a LDR (600Ω on/50M off) combo. Also, the diodes used in the originals are 1N5229 4.3v zenners, though you can use other zenners up to 5.1v. Here's the schematic for reference.
It's verified. I subbed TL071 for 061, LF356 for 351. VTL5C1 works on it, but LED/LDR combo, 5mm green undiffused LED and LDR with dark resistance of 10M, is OK as well. I have found no apparent difference between Vactrol and the combo.
What do you mean by undiffused? You mean the ones with the green or transparent acrylic? because they both have the green light obviously thanks anyway
The trimport seems to be too subtle with 5k value, but when the value increased it works on very unique way. In my case, somewhere between 500k and 1M would be fine and worth moving it externally. For builders of this pedal, I recommend to try some values before soldering it.
Hello. Where do I connect the led to show the oscillation of the "ON" effect? In the JOYO tremolo there is a trimpot option to adjust the volume and also an option to change the shape of the wave. Would it be possible to add these features in the tremulator? Thanks
Not sure how useful a volume control would be on this as it's output is about unity. But for the LED I'd trying putting another 1k resistor in parallel with the 1k resistor just to the left of the LF351. Then connect that resistor to the anode (+) of the LED you're adding with the cathode (-) going to ground.
Already made it on a breadboard. So far for me, the best DIY tremolo. I like the range of speed and depth. Got 2 problems at the moment though. First, a big volume loss second, a faint ticking at max level but not much a bother to me. Replacement of components: TL072 insted of LF442 TL091 instead of LF351 4148 instead of 4.3vzener Led/ldr combo 10k trimmer instead of 5k Thank You....
Cool! I like the smoothness. Def going to give this one a go. Thanks for the layout.
ReplyDeleteIt's verified. I subbed TL071 for 061, LF356 for 351.
ReplyDeleteVTL5C1 works on it, but LED/LDR combo, 5mm green undiffused LED and LDR with dark resistance of 10M, is OK as well. I have found no apparent difference between Vactrol and the combo.
Awesome! Thanks for verifying and the build notes too.
DeleteWhat do you mean by undiffused? You mean the ones with the green or transparent acrylic? because they both have the green light obviously thanks anyway
DeleteThe transparent kind. They're a tad brighter than the diffused types.
DeleteThe trimport seems to be too subtle with 5k value, but when the value increased it works on very unique way. In my case, somewhere between 500k and 1M would be fine and worth moving it externally. For builders of this pedal, I recommend to try some values before soldering it.
ReplyDeleteHello. Where do I connect the led to show the oscillation of the "ON" effect? In the JOYO tremolo there is a trimpot option to adjust the volume and also an option to change the shape of the wave. Would it be possible to add these features in the tremulator? Thanks
ReplyDeleteNot sure how useful a volume control would be on this as it's output is about unity. But for the LED I'd trying putting another 1k resistor in parallel with the 1k resistor just to the left of the LF351. Then connect that resistor to the anode (+) of the LED you're adding with the cathode (-) going to ground.
ReplyDeleteAlready made it on a breadboard. So far for me, the best DIY tremolo. I like the range of speed and depth. Got 2 problems at the moment though. First, a big volume loss second, a faint ticking at max level but not much a bother to me.
ReplyDeleteReplacement of components:
TL072 insted of LF442
TL091 instead of LF351
4148 instead of 4.3vzener
Led/ldr combo
10k trimmer instead of 5k
Thank You....
TL061 i mean
DeleteHi, I presume the drilling template for this one is the same as the one for compulator?
ReplyDelete