UPDATED:
A few people have asked how this mixer operates and sounds so here’s a wee video:
As you can see there’s a scratchy pot or two to clean and I still need to make some knobs, but so far so good.
Since I posted here about my fancy new plate reverb I’ve made a few adjustments and tweaks.
I’ve chopped the frame down closer to the size of the plate (about 600mm x 1800mm) and stuck a couple more piezos on it, but more significantly I’ve just about finished building a fancy new mixer for it. And when I say “fancy” I really mean “it’s the first mixer I’ve built and it works!”
The piezos seem to give the best results nearer to the edges of the plate (don’t know why) so I’ve got one centred at each end and one centred at each side like cross, and the inputs on the mixer are arranged to correspond to the placement of the piezos like so:
- left long
- left short
- right short
- right long
The switch on each channel is for determining stereo/mono. The two left channels can be switched LEFT or MONO and the two right channels RIGHT or MONO (e.g. in the picture above the channels are assigned to left, mono, mono, right). This simple arrangement allows for a surprisingly wide range of possibilities.
The mixer itself is insanely simple. It’s completely passive (no amplification) so it needs no power source. The circuit consists entirely of:
- the 4 input jacks,
- the 4 faders,
- the 4 switches,
- 2 sets of 4 resistors in parallel,
- and the 2 output jacks. In that order.
I used 4.7 k ohm resistors which seems pretty low according to what I’ve read and heard, but frankly I struggle with the theory of a lot of this stuff so I just tried a bunch of different resistors of different values until I found some which seemed to make everything work ok. The tin it’s all mounted in is mostly empty, so I should be able to fit plenty of other stuff (like preamps) inside without too much trouble if I ever want to.
Do let me know in the comments if you have any ideas or questions. I’ll post some audio clips here soon, probably after the weekend.
For now though, I’d just like to find some more screws and some fader knobs to finish it off. I’m sure there were some around here somewhere…
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6 Comments
Very nice Mr Delux, if it works then it’s right. For knobs on my sliders I’m going to drill a whole hole through them and the get bits of wood and cut a widish slit up them then screw them in.
I was going to use actual hen’s teeth for the knobs which would be just as easy to find, but yeah, I’m thinking wood too now. Or maybe aluminium, I’ll see what’s lying around.
Man I am so incredibly impressed by this. I gotta figure this out somehow.
Dope bro, completely passive…. aaaarrrrhhhhhh (sounds of angels singing)
Really like the sound you got there! my first impression was someone playing the bongos in a huge hall. serously man, youve done a great job!
Cheers Mike! It’s not a great reverb for everything, but I love how it sounds on this kind of percussion (and vocals, and a few other things).
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