Behringer UV300 Rate Mod (Slow Down)

I thought I'd take a quick venture into modifying a effects pedal. The one I chose was the Behringer UV300 ( Ultra Vibrato ) I love Behringer gear and in most cases they do a really good job at effects and pretty well everything they put their minds to (see the X3!)
anyway I bought this on a whim cause it was very very cheap, I didn't even bother looking for samples because if I'm honest there is only so many times one can watch people doing out of tune covers of Lucy In The Sky With Diamonds while reviewing Vibrato pedals - also they never turn the rate down to nothing to show you how slow it goes.

as you can probably tell by this post, the "rate" didn't go as slow as I wanted, I like that sort of hypnotic warped record vibrato which this pedal couldn't do however with a little knowledge of how oscillators work and a bit of time probing around with a scope I was able to modify this to go slow enough

In order to slow down the range of the Rate control you basically just have to add capacitors in parallel with C12 and C15 - or you can swap them completely for higher values - the higher you go the slower it is however you need whatever capacitors you add to be very close in value to each other because if one is very different you get an uneven vibrato.
anyway here are the pictures.

if you have any questions - ask!

and you don't need to rehouse behringer pedals, the plastic is very strong - it easily withstands being dropped down stone stairs many times.

solder very quickly otherwise you'll be resoldering SMD stuff!

it's a good idea to do this in order to tailor it to your preference

the part of the circuit I am changing

The Behringer UV300 with its nice new switch

Devils Triangle Drone Synth Stripboard Veroboard Layout

this is a project based largely on the put up or shut up mentality, for quite some time I've been getting annoyed at seeing youtube videos of people pissing about with these "synths" which are basically boxes of 555 timers with a million knobs that make stupid noises that you couldn't ever actually use in music so I thought I would make my own little synth that would get repeatable sounds and be useful in music and what better type of synth? a droner type - basically cause I love bagpipes - I like drones
anyway the circuit itself is quite a simple one basically because I only designed it during the week, all it is really is 3 triangle wave generators configured to operate in the audio range going into a mixer op-amp configuration with the odd filter here and there to soften the waveforms
I've used LM358 op-amps cause they are the cheapest, I'm not too sure if others would work in the same way though they probably will.

why call it the devils triangle - well it has 3 oscillators one of which can oscillate a slightly high pitch range (for melody) it also sounds demonic so the name fit

Hope you enjoy

EDIT: I replaced the level knobs with on/off switches - it makes it so much more versatile being able to silent certain drones 
EDIT: I added a little schematic on how the switches should be wired as it was causing a bit of confusion.

the one I made - with a really shit paint job

Flux Capacitor LED Decoration Stripboard Veroboard Layout

for fans of Back To The Future - or LEDs
I know this isn't exactly like the real thing however that would involve crux tubes and so on and I doubt many people who read my site want to piss about with 10,000 volt supplies. Anyway it's pretty much for my halloween/christmas/bonfire night decoration collection.

as you can see I have included a layout for the actual display board, although it looks like the LEDs maybe abit too spaced out, in practice they wouldn't fit when they are closer together. However should you just want to use the display board I think that each transistor can drive quite a few LEDs (I think the 2N3904s are rated at 100mA)
As it stands the circuit draws roughly 5mA

The last thing I want to mention is the odd value electrolytic (well odd to some) it is 470nf however you can use a none polarized version it just happened that I have both kinds and the electrolytic takes up less space

I also included a little video to show you what it does. HERE

Paul in the
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