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WIGGLING 'LITE' IN GUEST MODE

Coming soon! Turing Machine Bytes length modulator
MUFF WIGGLER Forum Index -> Music Tech DIY Goto page 1, 2, 3, 4, 5  Next [all]
Author Coming soon! Turing Machine Bytes length modulator
windspirit
*DOUBLE UPDATE* Last night I sent the final version of the gerber files to various synth DIY outlets! I will be starting a build thread soon and posting files so that you can make your own circuit boards. Thank you everyone for your interest in my first (but not last) DIY module!





https://soundcloud.com/60s-residue/pretty-bytes-arpeggios

This week I successfully prototyped an expander for the Turing Machine that would allow for loop lengths anywhere between 1 and 16 steps to be set by a potentiometer or a voltage. I am currently speaking with thonk and synthcube, who are interested in releasing the module and grayscale who is currently working on a panel. The project will be open-hardware just like the turing machine. It's peanut butter jelly time!

You should skip to the bottom of this post if you just want to see some demo videos.

So here are some details: you will be able to add this to an already built turing machine. It plugs into the "gates" output but it also will double the pin header so that it can be used in conjunction with the "voltages" expander. There are two knobs that set the long and short length of the loop, with the range being selected by the original switch that used to select between 8 and 16 steps (now it selects between 1-8 and 9-16 steps depending on knob and voltage values.) There is an attenuverter for the CV input and a switch to select whether the CV is affecting both loop lengths, just the short loop length or just the long loop length. There is only on CV input (aka you cant have each loop length controlled by separate CVs) since it would greatly increase the complexity and size of the panel/ PCB. The panel is 4hp and I measured the current draw at ~65mA on the +rail, didn't check the negative rail but it should be much lower.

The only somewhat daunting task for a beginner in this project would be that it involves a trace cut. It is possibly the easiest trace cut you can do - far away from other traces and close to the side of the board, so it should be easy to to even with a built unit. This was necessary to keep the original length switch as the current length switch and also to isolate bit 8 from the "end of loop" bit in 8-step mode.

Attached is the schematic for bytes. It is the first schematic that I have ever drawn in eagle so I am very sorry if it is dreadfully sloppy. I am more than open to suggestions for anything that can be improved either design-wise or layout wise. I want it to be easier for people to read since they might be modifying it down the line. I would just ask that you refrain from doing the layout- part of the reason that I volunteered to do this project is because I need practice designing PCBs on the computer.

A bit about how it works: the op-amp at the beginning takes a eurorack-level input signal (-12 to 12V) adds two offsets (one for each length knob) and scales each output to be 0V- 9V. The offset is designed so that with no input voltage it can still sweep the entire range. There are protection diodes to keep the outputs of the opamp circuit strictly within .2V of that range, which is according to the spec of the ADC0820s. This is a "parallel" ADC, meaning that it outputs the binary value of the input bit-by-bit on each of it's pins every time it converts a new sample. The 555 timer at the top is generating a sampling clock ( ~ 200 KHz ) for the ADCs. Each ADC converts a separate signal and uses the most-significant 3 bits to feed a CD4051 switch IC. This IC switches between the 8 gate outputs of the "gates" expander header, selecting which bit to connect to depending on the output of the ADC, and outputs the result to the "end of loop" connection for either the short loop or long loop selection. For short loop, this is the top pin of the length switch, which is where the trace is cut. For the long loop, this is pin 7 of the original 4015 socket. In order to have access to the long loop bits the secondary 4015 (the one that allows for 16bit loops) is transferred to the expander. It's input and clock pins are connected to the gate-8 and clock header pins, so it behaves exactly as before. The 8 bits in it's register are connected to another 4015.

I want to thank Daverj, neutron7 and mxmxmx for helping me work out some kinks in the opamp section of this schematic. Of course I would also like to thank Tom Whitwell for making such a lovely module and open-sourcing it.

Enough talking, here are some demo videos! Im sorry for how low-effort these demos are, I will whip up something sexier for the completed module.










Hope you enjoyed grin. Pix of the new board and schematic will be posted soon.
waveglider
Nice work!! I think this will be a great expander to have for the Turing Machine, the CV control over steps is super cool SlayerBadger!
Poldenstein
nanners nanners nanners
mapmap
the turing machine keeps getting better and better
Monobass
Really excited about this. It really takes the Turing to the next level for me. 3 and 6 note patterns FTW SlayerBadger!
lintfresh
Neat!

The TM sure is the gift that keeps on giving. thumbs up
bartleby
très cool!
synthcube
fantastic!!
en.
ubercool!
oberkorn
wow. didn't see this one coming we're not worthy
count me in for one or I'll build one if I find the time
kindredlost
Wow! Nice work windspirit! I'll be watching the kit release. I want this for my TM's.
sempervirent
Here's the preliminary panel design. 4hp.

horstronic
Very nice!
A thonk kit would be nice!
sammy123
I be interested in a matching black acrylic panel. Spirograph would be cool.
kindredlost
Nice panel. I would be so bold as to suggest the switch read (from top to bottom) 1-8, 1-16, 9-16. To me it would be more like the "middle" position to be all inclusive that way. It might be easier to grog with a quick glance.

Otherwise it all looks good.
mckenic
No idea whats going on - but I like the sound and would happily be in for a kit!

(Im sure I will cop what is happening at some stage!!!)
Monobass
sammy123 wrote:
I be interested in a matching black acrylic panel. Spirograph would be cool.


yeah I'll do sweeping arcs and spiro variants and full kits for sure thumbs up
sammy123
Monobass wrote:
sammy123 wrote:
I be interested in a matching black acrylic panel. Spirograph would be cool.


yeah I'll do sweeping arcs and spiro variants and full kits for sure thumbs up


Awesome.
Poldenstein
Monobass wrote:
sammy123 wrote:
I be interested in a matching black acrylic panel. Spirograph would be cool.


yeah I'll do sweeping arcs and spiro variants and full kits for sure thumbs up


It's peanut butter jelly time! It's peanut butter jelly time! nanners nanners It's peanut butter jelly time! It's peanut butter jelly time!
concretic
Excellent, I am in for grayscale kit!
djthopa
Im in!
synchromesh
That does look very cool. I'd be in for Grayscale panels and Thonk PCB & panel kits. SlayerBadger! screaming goo yo
yan6
Super cool, cant wait applause
Ginko
Nice work, I would be up for a Grayscale kit as well thumbs up - without wishing to derail at all, but I use my TM pretty much everyday at the moment and what I would really like is VC over the Scale functions hyper
bartleby
Ginko wrote:
what I would really like is VC over the Scale functions hyper

i think what you're looking for is called a 'vca'. hihi
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