EQD Hummingbird pedal is screwed!

samzadgan

So last night I was playing and I clicked on the Hummingbird pedal...and it wasn't working.

every other pedal on the board works fine and the when the hummingbird is on everything else is working as normal too.

i played around with the knobs and noticed that the depth knob was working as a reverse volume type effect and the level knob was working as it should...but there was no effect (tremelo) besides that.

not sure whats going on with it...maybe the circuit is screwed? its become so true-bypass that there is no tremelo anymore.

any advice would be very helpful.

lasermonkey

I can't find the schematic at the moment (it's a modified Vox Repeat Percussion, IIRC) but I have a feeling the 2N2646 UJT may have failed. It's a finicky circuit and the UJTs have to be selected for the circuit- some work, some don't. And they can fail. Whilst being obsolete components, they are still available from eBay, though you may need to try a few until it works. If, of course, that is the problem! It's always worth seeing if there are any loose wires floating about first.

samzadgan

thanks @lasermonkey...i couldnt see anything obvious inside...but then again i wouldn't know what to look for...here's a gut shot:

samzadgan

So got a response for EQD...and i dont understand...so if any pedalbuilders want to do this for a small charge, let me know...

"Chances are good that the jfet (2n5457, right in the center of the PCB) has gone bad"

dano

What they mean is the transistor is a 2n5457, head up from the 3pdt swicth, there are five red wires soldered to the board, then two capacitors located below the two birds. between these two caps is the suspect transistor.

2n5457 are easily available, i might even have a few in the shed. (but i'm fairly snowed under with jobs so not volunteering to swop it, unless you get really stuck with no takers !)

lasermonkey

I'll have a look at it for you, if you want. I have plenty of 5457s and even a few 2646s. I doubt it's anything difficult. PM me if you're interested!