The Joyo Tremolo is a "pretty good" tremolo out of the box for under $30, pleasant and traditional tremolo sound. It is also very close to the Demeter Tremulator ($200) and can pretty easily made to sound almost exactly the same.
First a review of the build quality. Everything is PCB mounted except for the footswitch, which is connected on a 6-conductor ribbon cable which is extremely fragile and easy to damage when working the parts around. Be very careful with these tiny wires, they snap almost by themselves.
The PCB is pretty weak, I had several pads lift when re-working parts, so be as gentle as you can when doing the re-work. This is not a pedal to work on over and over, it will fall apart. Like the Behringer and Alesis compressors in some of my recent posts, this is not a product that's been built to last or really even be repaired.
Luckily the enclosure is pretty solid, the jacks are standard quality, not the worst, and the footswitch is a pretty standard 3PDT as well. It seems like if you can get the work done and get it back together, it might last a while.
I really like this after the mods, it sounds exactly like Radiohead stuff with the Tremulator. In my mind this is what a pedal tremolo should ideally sound like--excellent.
This is the video where I got these ideas from:
http://youtu.be/aB5xV99VXKI He also has a square to triangle wave shape pot mod that I skipped. I found one more improvement on his mods as well, he didn't change the rate pot to Demeter value. Without this mod the rate pot has a very bad range.
MOD LIST:
C5 - Change to 4.7 uF **non-polar**
R16 - change to 33K
C6 - remove 220pF cap
Rate Pot - change to 500K B or C taper
Optoisolator Bias Trim Pot - adjust to deepest setting for full silence on maximum intensity. Or back it off if you like that gentle sound. I like the dramatic deeper one, sounds more like a Tremulator to me.
R16 is right between diode 3 and the IC next to it.
C6 is the maroon colored film cap code "221" next to the diodes.
C taper, Anti-Log, is a really good sweep on the rate knob. B taper, linear, is Demeter spec and would probably be fine too, I used C. So did Bajaman on his Trembulator.
I also had to drill around the power jack a bit to enlarge the hole since my rate pot was a bit thick and moved things around slightly when reassembled.
And then I put some fancy Demeter/Marshall style knobs, looks great sounds great! I built a Tremulator from scratch, gave it to a friend, have missed it ever since, finally got one back in my collection for minimum investment...very satisfying. And that's a cool mean dog graphic too.
hello! i just finished this mod, and it works out real nice! thanks!
ReplyDeleteone question, my rate range changed such that i have much more "fast" level of rate, but also much less "slow" level of rate. i'm wondering if i did something wrong...otherwise it is awesome! let me know what you think - thanks!
If you did the full mod I recommended, a 500K "C" taper pot (anti-log, reverse audio taper) gives a very good sweep on the knob.
DeleteI'm not sure what you did but I can say for sure, if the slowest sound is slow enough for you and not too slow, and the fastest sound is fast enough for you, then you can bring the "A" "B" and "C" taper into the equation which will give the exact same speeds at maximum and minimum control settings, but will "spread" the speeds out this way or that way depending on where you want or need more or less control.
If it doesn't get slow enough for you, you might want to use a different pot value altogether. I haven't tried it but maybe a 1 Meg pot would get really slow. Was that the original Joyo value? I can't recall. You could also add a resistor in series with the rate pot to slow down the fastest and slowest rates at the same time, I think. Personally I don't have much use for the slower speeds, but I do like going helicopter fast sometimes, so the 500K "C" is just right for me.
I believe the Tremulator is tuned a little faster (what I want) and the stock Joyo speeds are tuned slightly slower. If you prefer that you might want to switch back some of the values in the Joyo stock direction.
Also double check your work and component values. And thanks for the comment! I'm so glad someone got something out of this blog, I'm chuffed.
I first switched out to a 500K "C" anti-log taper pot, but it just didn't seem to have any range at all, then i switched to a 1M "B" taper, and i got a nice range back. i also tried a 1M "C" anti-log taper, and again no range at all.
Deletei went back and checked the Joyo pot, and it is a 500K pot - do you know what yours initially came with?
i do like where it currently is at - sound and range wise, but i'm just getting into this circuit stuff, so my brain just wants to know how all of this works...so, i'm trying to figure out why i lost the "ultra" slow speeds. does it have to do with the resistor or capacitor modifications? or do you have any insight on why i'm having (what seems to me) unusual reactions with "no sweep" using anti-log pots?
check out this or any article on pot taper:
Deletehttp://www.resistorguide.com/potentiometer-taper/
I'm not an expert on tremolo circuits, but if you look at the "Loop" on the LFO section of the schematic, I believe the delay time is set by the total amount of series resistance in the loop. That would be the speed pot, and probably some of the other resistors in that section. Most likely the "tremulator mods" altered some of these values. I would recommend to experiment and see what you find. A breadboard, or some alligator clips, might come in handy for quickly substituting parts.
It's also possible that you might have messed something up, because if you follow my guide "to a T" it should work perfectly.
Good luck!
any chance you added an anti-pop resistor in the circuit? my joyo trem is popping when activated and not great for quiet ambient moments.
ReplyDeleteI have not no, but that's simple enough. Use a 1 MegaOhm resistor from signal in to ground, or signal out to ground, as needed. This will discharge any capacitors on the input or output so there's no pop when switching. Should not change the sound of the pedal at all.
DeleteHello,
ReplyDeletedoes C5 have to be a elco? i replaced mine with a ceramic, and now all the pedal does is generate a single tone, which i can control the pitch through the rate control. weird thing being it's always audible, not only when the pedal is turned on.
That is very strange, I am not sure what's going on there! I would stick to the regular type/value I guess, hopefully no problems with sticking to the schematic.
DeleteHello, just got to your mod.
ReplyDeleteI have that tremolo pedal, except its Harley Benton and not Joyo what is the same.
I didn't understand some of your explainantions (eg: about the bias trimpot, mine is 20k by default, already turned all the way up, can i change it for bigger value?)
The Intensity potentiometer is a 50k one by default, can i change it to something bigger for something more square wave like?
maybe you could add a picture of the PCB with legend pointing to the resistors etc you are acting on? i might be really noob friendly <3
i made a post on fsb trying to get some help on this, dunno if i can put the link here http://www.freestompboxes.org/viewtopic.php?f=33&p=258911
thanks for sharing all your work!
Hopefully the FSB guys can get you sorted out. The Bias trim pot controls the brightness of the LED inside the optoisolator. I think a bigger value will probably just make it dimmer, decreasing the depth, or intensity of the tremolo effect. If you are going for the "hardest" sound you probably turn the trim pot all the way down, for the brightest LED setting inside the optoisolator. You may want to take a look at some other tremolo circuits like the Tremulus Lune to see how they accomplish the different waveforms like square and triangle. Just spitballing here, hope I am not totally off base! good luck.
ReplyDeleteDoes it still suck the volume when the intensity is increased?
ReplyDeleteI haven't noticed that. But if you did find this to be the case, You could probably bump up the gain on the output op amp.
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ReplyDeleteHi Monkeyxx, recently got the Joyo Trem and love it (and I own a Demeter Tremulator too). I want to do the faster speed mod w/o any tonal change to the original circuit. Will just changing the pot value do this, or are there other things that need to be changed? Any help would be muchly appreciated. Thanks so much.
ReplyDeleteYou can watch this around 4:40 https://www.youtube.com/watch?v=aB5xV99VXKI&feature=youtu.be
DeleteThat timing cap (4.7uf), the 33K resistor, and the potentiometer value will determine the overall speed range. You could probably just change those two or three things. Maybe it's best not to change the pot, actually, so it fits how it should in the enclosure. I feel like a MORON but I'm not sure what changes with a larger pot value, possibly faster speeds, according to the video above. He says the 33K resistor in place of the stock joyo 100K resistor "allows for those slower speeds." Maybe you just simply want to change your pot. I might suggest buying a 9MM pot replacement rather than a standard 16MM pot since the 9MM should fit the Joyo better. Mammoth Electronics sells pots like these.
At some point the fastest speed will be limited by the opto cell itself, so keep that in mind. That happened to me when I was trying to get a hyper fast speed from the 4MS Tremulus Lune.
DeleteAlso just increasing the 100K resistor to something hihger will "shift" the whole speed range without changing the pot. I would expect the slowest speed to be faster, and the fastest speed to be faster as well. You'd be losing some slow in favor of fast. Really, getting the knob feel and speed range is the most critical part of this pedal for me. That is why I love the Tremulator circuit with the "C" taper pot I landed on.
Thanks so much. Yes, I'm really interested in having faster speeds, as the slowest speed is really too slow. Having the whole ratio faster is aok. That and modding a sine to square wave external control.
DeleteI did find the correct - Alpha Single-Gang 9mm Right-Angle PC Mount
500K Rev pots @ http://www.smallbear-electronics.mybigcommerce.com/. Thanks again.
Hey there, having a problem - I just tried to do these mods, and things seemed to be working great til I got to the last step of removing the 220pf cap from C6. Now it only works for 30 seconds or so and then seems to "power down" - the tremolo speed gets slower and slower and then it stops doing anything (can still play thru it, but no trem and no blinking light). If I leave it for a while and try again, same thing - it works, briefly, then stops.
ReplyDeleteSadly I wrecked the original cap when I pulled it out, but I tried replacing it with a 1000V 220pf cap, then with a 50V 220pf cap, and it was the same problem as with no cap.
Before this I did the wave shape pot mod, and swapped C5 and R16 as you described.
Any thoughts? I'm pretty green at electronics and this has me totally stumped! Thnx in advance for your help, if/when you have time, and many thnx for putting this info up!
Anyone got a schematics of the original Joyo Tremolo? I cant find the defect, so i need to take a diagram for that. Thnks
ReplyDelete
ReplyDelete225/5000
Hello. Is the resistor R11 that changes the wave form the same resistor R11 in the diagram of the Tremulator? I was in doubt because there are two 10K resistors in the schematic. Is the numbering of the joyo pcb and diagram components the same?
Thanks.