Tremolo kvetching.

[vizcities]

So: it feels like nearly EVERY time I try to build a tremolo, the thing just won't work. It's maddening. The list of builds I've attempted (and concluded in abject failure) include

+ A Frantone Vibutron (vero)
+ A Frantone Vibutron again (Effects Layouts PCB)
+ An EA Tremolo (vero)
+ A BYOC EA Tremolo (vero)
+ A GuitarPCB EA Tremolo (PCB)
+ An EA Trem I won in a PIF (I think?) a year or two ago (PCB)
+ A Schaller Tremolo (vero)

The EA trem was for my brother, and he definitely looked at me cockeyed after the fourth attempt. And I don't blame him! Given that the EA trem is such a standard DIY project, my failure rate is almost embarrassing. It's not all bad - I did manage to get a Fuzzdog EA Trem sorted, though it's very finicky and weird about true bypass. Many moons ago, I also got Jon P's Cardinal trem to work and it's nice, though more helicopter-y than what I tend to use for most songs. Still, I don't understand my problem here. Why is this such a blind spot for me? I mean, for example, I spent three hours on the aforementioned Schaller this afternoon. And, despite judicious use of isopropyl alcohol and component measurements up top, it's not producing sound. (I went into full-on troubleshooting mode, too: I checked the entire thing for continuity issues, looked for cold joints, reflowed the whole mess, rewired everything, replaced pots, scored the lines between strips, and recorded voltages. Weirdly, I had the exact same issue with a Lemon Drop build later in the day, so who knows what's afoot... maybe the problem is veros? But I have completed plenty of functioning veros, as well as failed to make plenty of trem PCBs work. And as far as I can tell, continuity is solid on my offboard wiring...)

I'm not kidding when I say this is maddening. I don't have EE level skills or anything, but I've made something like 50 pedals/projects, including complex BBD things, phasers, autowahs, like 10 overdrives, 20 fuzzes, PT2399 delays, reverbs, Ruby amp variations, a Deacy amp, 5 or 6 microphones, and stuff for touring friends. Trems seem to be my kryptonite; outside of the opto realm, it feels like I'm cursed. Does anyone else have this problem? What do you think the issue is?

On a related tip: if anyone has a functioning-but-unboxed Vibutron circuit at a reasonable price, I'll take it off your hands. There's no pride left here... I just want a nice trem w/a sinusoid option, and I have a box drilled and waiting for a finished circuit.

[mjg]

Wow, I admire your persistence!  I would have given up after two or three. 

[alanp]

What do the nonworking trems use for control? Vactrols, or OTAs?

[midwayfair]

Get a breadboard. Failing this many times with any builds that you can't successfully troubleshoot means that you would be well served by understanding the circuits in general better.

A tremolo circuit is an amplifier circuit and a low-frequency oscillator. You can built these parts of the circuit separately and play around with them, and more importantly you can check where the voltages are different from the builds you've tried to make or swap out parts.

The EA trem, which you've tried to build multiple times, is not a fool-proof circuit. It is sensitive to the transistor used and resistor-capacitor network in the feedback loop. But it's dead simple to breadboard. So breadboard it.

Alan: The EA just uses an AC voltage output from the LFO to a transistor base as the control. The Frantone uses an L8038, which is a chip that makes the waveform for you.

[vizcities]

MJG: Haha, thanks... I'm nothing if not doggedly persistent. (Like Captain Ahab.)

AlanP: What Jon said. And he's right - I don't actually understand how the failing circuits work. Unlike other stuff, I really haven't picked up the fundamentals of why a non-vactrol trem does what it does, so detailed troubleshooting is a definitely a problem.

Jon: This is good advice, and probably a long time coming. I've mostly taken a "10,000 hours" approach to DIY pedal expertise when it comes to building in the past, meaning I'm industrious-but-lazy: principles have been learned as I've gone along, but I've avoided breadboarding. (This is similar to my problem with studying languages... though I will memorize words and read short passages for days, I always seem to put off the dedicated oral and grammar work that fluency actually demands.) It does seem like it's time.

[EBK]

Buy a known working tremolo and try it in your house.  Maybe it's a geomagnetic problem.   

Sorry, I don't have a serious suggestion, but I feel your pain.  Keep at it though.  Victory will be all the sweeter from your efforts.

[vizcities]

Sweet victory update: I built Fuzzdog's Schaller (a.k.a. Throb) trem and it's great! I like it so much that I'm selling my Fulltone Supa Trem and seriously considering tossing my Source Audio Vertigo, too... between the Schaller, the Cardinal, and my DRRI's trem, I think I'm beyond covered.

[selfdestroyer]

Is it possible that all these fails terms use a part that you might have in the wrong bin or miss labeled? I had this happen one time with some odd ball resistors that I just did not use often, but when I did they were the wrong value and messed with the build. I now measure all parts when populating a PCB just for this reason.

Just a thought.

[dawson]

Maybe it's a geomagnetic problem.

From here on out, I'll be blaming all of my failures on uncooperative geomagneticism.

[Muadzin]

So: it feels like nearly EVERY time I try to build a tremolo, the thing just won't work. It's maddening.

I have the same thing with flangers. Can't get any of them to work. Tremelo's in contrast always fire up first time without a hitch. It's the Universe having a perverse sense of humor.

[Aleph Null]

Don't feel too bad: the only thing that has ever stayed permanently in my fail pale is an AE Tremolo. I can attest to what John said about the circuit being surprisingly picky about transistor choice.

[Netnnk]

Good you got it working.  I'd like to recommend Madbean's own Stutr to the list for others to try.  I got it not knowing much about it but does all I need.