Hi all
This is based on Alan P's excellent layout Tremopanation. The boards say 0.3 on them, but I'm sure this is 1.0. Anyway.
Its a recreation of the classic Lovetone Wobulator dual tremolo/vibrato/panner pedal.
There are 4 modes.
1 TREM - both Left and Right move up and down at the same time, but with a "cross-over" effect where Left is low pass filtered and Right is high pass filtered.
2 PAN - Left and Right move in anti-phase without a cross-over, akin to a normal "figure-of-eight" auto-panner.
3 VIB - same as TREM but in anti-phase, creating subtle phase cancellation (and therefore pitch and volume change) effects.
4 DUAL TREM - this again uses the cross-over but brings into play the second LFO. Left is now driven by LFO 1 and right by LFO 2.
1 - 3 are all driven via LFO 1 only, which I wasnt completely expecting.
And because of the various cross-over and LP/HP filtering in some cases, you need to activate both L and R footswitches to get the most out of them.
That being said, with the modes where there is filtering, you can access independantly the same rate setting on L and R, but subtly different sounds, by activating only one of the two footswitches, and sum to Mono.
4 - this is the really cool one, dual speed independant LFOs. Kinda like the Doppelgangers dual LFO mode, but trem rather than phaser. Ace!
Obviously with 2 amps its a whole other story. I have had a 10 minute play with 2 amps, and it sounds incredible.
Overall its extremely versatile with many subtle variations in sound. If you like trem, this is one to beat perhaps.
The only lacking thing is tap tempo of course.
One final item to figure out is why R has a tad more hiss in the sweep then L... Alan might have some thoughts on that.
I added the output transformers and phase switch. I didnt get any buzzing or grounding noises with 2 amps regardless of placement of the phase switch. Still, nice to have it. Quite a squeeze to get it all in a 1790ns, I had to omit the trigger input, but retained the speed expression input (so far untested, but Alan has verified it...)
This would probably make more sense in a portrait orientation; I have 2 other boards from osh so might build one that way and see :)
The only other thing left to do is try some other vactrols, as Alan noted it could use some more depth perhaps. Right now I just have unknown LDRs from Tayda in there so god knows (!)
aaand heres the pics:
(http://i1178.photobucket.com/albums/x374/LaceSensor1/Wobuliker/IMG_2567_zps0bfe26df.jpg)
(http://i1178.photobucket.com/albums/x374/LaceSensor1/Wobuliker/IMG_2566_zps7f8edd9e.jpg)
(http://i1178.photobucket.com/albums/x374/LaceSensor1/Wobuliker/IMG_2561_zps0456233f.jpg)
(http://i1178.photobucket.com/albums/x374/LaceSensor1/Wobuliker/Outputtransformerwiring_zps5761db9b.jpg)
Thanks Alan for a wonderful project. I doubt Id have ever played a Wobulator if not for this.
ps it doesnt tick. I could detect a tiny bit at first, so I added shield cable to the input and that has solved it.
QuoteOne final item to figure out is why R has a tad more hiss in the sweep then L...
You said that the right is high-passed, right? So the left is cutting some of the noise with its low-pass filtering, unless the filtering disappears in other modes.
If you're running both sides in mono, does the trem mode sound "normal"? Or is there some mid scoop when they're summed?
What's the bypass scheme on this?
Overall very nice. :)
Quote from: midwayfair on February 24, 2014, 07:55:27 AM
QuoteOne final item to figure out is why R has a tad more hiss in the sweep then L...
You said that the right is high-passed, right? So the left is cutting some of the noise with its low-pass filtering, unless the filtering disappears in other modes.
If you're running both sides in mono, does the trem mode sound "normal"? Or is there some mid scoop when they're summed?
What's the bypass scheme on this?
Overall very nice. :)
Ill have to check that all out again but the HP / LP filtering thing sounds like its probably the answer.
There isnt any wierdness / scooping with summing to mono. It sounds great to me.
Its buffered bypass.
Quite a project!!! I imagine that's a perfect execution of a Lovetone circuit.
Any chance of a sound sample?
Tayda LDRs are specced at 500k dark. It's worth experimenting. My trafo's are finally shipping from mouser, and I'm going to experiment with LDR's when I put them in (not energetic enough to bother till then.)
Lace, I'm always amazed by how tidy your Lovetone builds are (as well as the artwork :) )
Oh yea, and the boards are 1.0... I just forgot to edit the text on the board :-[
Trivia, I could have done this with two dual opamps and not three, at the moment two of the ones on the board have unused opamp sides, but figured that having isolated chips (rather than share a chip across different parts of the circuit) would help with tick isolation.
Quote from: alanp on February 24, 2014, 08:16:29 AM
Tayda LDRs are specced at 500k dark. It's worth experimenting. My trafo's are finally shipping from mouser, and I'm going to experiment with LDR's when I put them in (not energetic enough to bother till then.)
Lace, I'm always amazed by how tidy your Lovetone builds are (as well as the artwork :) )
Yeah I will have a mess around. Ive got a bunch of different ones, about 4 different Futurlec types. I just wanted to hear it working.
Thanks for the tidyness comment. I do try! This one coulda been neater, but its always tough to know the first time, and a couple wires coulda used a tad more slack to allow bundling together with cable ties. Nevermind. Its not untidy, for sure!
Quote from: alanp on February 24, 2014, 08:22:59 AM
Oh yea, and the boards are 1.0... I just forgot to edit the text on the board :-[
Trivia, I could have done this with two dual opamps and not three, at the moment two of the ones on the board have unused opamp sides, but figured that having isolated chips (rather than share a chip across different parts of the circuit) would help with tick isolation.
i think for the $0.30 required to buy another TL072, you made a wise choice.
Ok so really turning amps up, and moreso in stereo I feel, there is a tiny tick. Its in no way as bad as the low profile dopp 1.4
I'm going to add screened cables to the transformer outs.
:( Sod. Stupid tick.
Big question is, is it as bad as the stock unit's ticking? ;)
Don't own a real one (yet)
Ian
good news, everyone
Tick solved. Shielded cable on the outputs to the transformers, with the shield grounded to signal GND.
Such happy. Many success.
Impressive build Lace. Glad you got that tick sorted. It was on the pedal not you right?
Really nice build. I like labeling a lot: with that many knobs and dials it could get cluttered but that looks nice and neat.
Quote from: pickdropper on February 25, 2014, 08:47:28 AM
Really nice build. I like labeling a lot: with that many knobs and dials it could get cluttered but that looks nice and neat.
cheers. I blatantly just rip off the real ones...
Some more info, I did a lot more work on tick minimization than Ive written about so far, including adding an input buffer, shielding various / all cables
In the end it seems proximity of the rate input exp jack to the input jack was getting some cross talk. Ive got rid of it now on my build by moving stuff around etc and using different jacks to get the connections as far away from each other as possible. I will post a pic below which should seem obvious.
Long and short though is that any future builds will likely be "portrait" orientation, to allow more room to isolate the jacks at the bottom. This will likely work cool anyway, as it will allow me to place the foot-switches closer together also. I dont think the buffer is necessary in hindsight; added bonus I have a (modified) Klon buffer in here too, ha.
All told this has been a fun build and learning exercise; I didn't expect to have to try so many things but I have figured out what does and doesn't "count" with making this circuit quiet and tick-less
Final pic of the "proof of principal" study:
(http://i1178.photobucket.com/albums/x374/LaceSensor1/Wobuliker/wobmash_zps96b8c554.jpg)
lace you should make a demo of this and the phaser :)
Huh. I had my rate exp pot at the top of the enclosure, and the input jack at the bottom of mine (the enclosure had a big ridge in the middle inside I didn't want to go near.) Probably why I didn't strike this.
Quote from: alanp on February 25, 2014, 08:15:28 PM
Huh. I had my rate exp pot at the top of the enclosure, and the input jack at the bottom of mine (the enclosure had a big ridge in the middle inside I didn't want to go near.) Probably why I didn't strike this.
True that.
I will know for next time
Quote from: monkeyssj1 on February 25, 2014, 07:24:05 PM
lace you should make a demo of this and the phaser :)
Maybe ;)
Just built my own wobulator, and came upon this topic via google. I thought I'll ask here in the topic instead of posting a new one.
There are a couple things with my clone that seem odd:
1.) Still have some ticking noise although the LFO Pedal Jack is not really near the input. Input wire is shielded. Pedal LFO wire too.
2.) One LED is a couple of ms behind even in Tremolo Mode where both LFO's should be syncronised. Not a big issue on higher LFO rates but you really hear it when you use the pedal in stereo. Is this due some part tolerances?
3.) I can still change the rate of LFO2 even in Tremolo Mode, the LED blinks in a rather unconventional waveform, it doesn't looke like a triangle or a square. I have a hard time distinguishing the different waveforms, on my clone I have the impression that I only have 2 of them, the other 2 positions sound exactly the same.
Other than that everything else is working
P.S Bought a doppelganger PCB a while ago from you Lace, clone turned out great!
Quote from: Drey23 on August 22, 2020, 04:07:00 PM
Just built my own wobulator, and came upon this topic via google. I thought I'll ask here in the topic instead of posting a new one.
There are a couple things with my clone that seem odd:
1.) Still have some ticking noise although the LFO Pedal Jack is not really near the input. Input wire is shielded. Pedal LFO wire too.
2.) One LED is a couple of ms behind even in Tremolo Mode where both LFO's should be syncronised. Not a big issue on higher LFO rates but you really hear it when you use the pedal in stereo. Is this due some part tolerances?
3.) I can still change the rate of LFO2 even in Tremolo Mode, the LED blinks in a rather unconventional waveform, it doesn't looke like a triangle or a square. I have a hard time distinguishing the different waveforms, on my clone I have the impression that I only have 2 of them, the other 2 positions sound exactly the same.
Other than that everything else is working
P.S Bought a doppelganger PCB a while ago from you Lace, clone turned out great!
1) Unless you are meticulous its hard to eliminate. Try various things then try again.
2) Dont know the answer to that. In the first three modes, the Left and Right "sides" should be syncronised entirely, as they are driven from LFO1 only. The fourth mode brings in the second LFO, meaning you have have separate rates for the Left and Right "sides".
3) Sounds like your rotary switch is borked, or youve got another issue somewhere.
For the avoidance of doubt, there are TWO LFO waveshapes on a Wobulator, FOUR different "tremolo" type of arrangments, and either ONE or TWO LFO oscillators.
There are 4 modes.
1 TREM - both Left and Right move up and down at the same time, but with a "cross-over" effect where Left is low pass filtered and Right is high pass filtered.
2 PAN - Left and Right move in anti-phase without a cross-over, akin to a normal "figure-of-eight" auto-panner.
3 VIB - same as TREM but in anti-phase, creating subtle phase cancellation (and therefore pitch and volume change) effects.
4 DUAL TREM - this again uses the cross-over but brings into play the second LFO. Left is now driven by LFO 1 and right by LFO 2.
In Mode 4 (Dual Trem) LFO1 drives the left side, and operates at lower frequencies than LFO2 which drive the right side.
Each LFO has the option of either a TRIANGLE or a SQUARE waveform, indicated by the four different selections on the (other) rotary switch.
IF you are getting any sort of waveform that doesnt look like a square or a triangle, then you made an error in the build.
Trigger and Pedal options only affect LFO1.
Thanks for your purchase of the Doppelganger PCB and I am glad you enjoyed the process and product.
Cheers, Ian (Gigahearts_FX)