AMNESIO SL-1

lo-bit circuit bent looping sampler / destroyer

click image for larger version

first let me say that if you are looking for something you can play with your feet while you strum a guitar or if you are looking for something that will properly reproduce a recorded sound, this is not it, stop reading and go the fuck away.

now for those looking for a new heart to your current noise setup or anyone interested in temperamental destruction, this is the AMNESIO SL-1 and it will all but forget what you just recorded and push out a bastardized, distorted, bit crushed, hissy, whiny, filthy interpretation of it. the guts of this contain a little 1980's digital personal recorder i stumbled on and then managed to find 4 more of ( then destroyed 3 of !!! ). in the research i did i could only find info on the static ram chip which claims to be 8-bit but the actual AD/DA is masked under the ubiquitous black gum drop, leaving me to make wild guesses. i'm going to say that this is not even close to 8-bit, and the input seems to have some sort of preset compression built in that i can not bypass. so no matter what volume you feed it, its the same heavy, grainy, distorted mess. i've spent 2 solid days with every method i could find, trying to make it cleaner, adding every manner of db pad, attenuation, buffering, etc... and no matter what the source, be it mic, guitar, line level, it all came out the same, so i gave up. it is what it is, there is nothing to be done about it. accept the destruction.

alright now lets get into the functionality, there is a lot to explain! first the bad stuff. it's bent so there are a few quarks. the way this needs to be thought of is as a constantly running tape loop, but with one single head, meaning that you can either record or play, but not both at the same time, because of this you can not monitor the recording as it is happening, you're completely blind, there isn't anyway around this (*UPDATE: if you leave the crash switch on you will hear a very distorted version of what you are recording but having it on will not effect the recording ) and when you drop it into record it will record until the end of the "tape", when this point is reached the green led indicator will shut off and the indicator tone telling you that you are recording will stop (*UPDATE: this tone no longer exists ). then if you want to keep recording you have to hurry up and flip the record switch off and then back on again or there will be a "gap in the tape" if you follow me. now if you are in fact following along then you might ask what’s going to fill that “gap”. well this part also works like a tape loop, so the gap will be filled with whatever was previously recorded. fuck yes! it will only record over the sections of the "tape" that you choose! instead of just blanking everything out like other samplers. so if you have already recorded someone talking for example and then you want to record some sort of melody, or noise you can flip the switch rhythmically on and off, over and over and create a "cut and paste" recording, where the "off" is still the voice and the "on" will be the new melody or noise bits. very cool, and its all non-volatile so you can record something at home then shut it off and take it to a show and it will still be there when you flip it into play ( as long as you don't remove the battery ).

now, i should point out the clock / speed / pitch thing. at its fastest speed / highest pitch it is maybe a couple milliseconds, and i sat and timed the longest sample length at about 1:56 minutes on my prototype, but at that length everything is total shit noise. so with that in mind let me point out that unlike most samplers you can set the speed / pitch knob to whatever speed you want and get that length. its not the sort of thing where you can only record at one fixed speed, for example: 50% and then change it after its finished. you can set a 10 second loop speed, record it at 10 seconds, and then pitch it down to 2 minutes in length, AND you can adjust the speed DURING THE RECORDING adding permanent speed / pitch modulation, which is as cool as it sounds. playback can then be pitched again. with the pitch being this huge ( not sure how to measure it but i'd take a wild guess and say about 20 octaves or more ) i have added a big "course" knob and a "fine" knob to help dial in whatever pitch you are trying to get. i have also added a large momentary play button in addition to the toggle play / off / record switch so you can trigger play on and off in time with whatever you want, but understand that the clock is constantly running ( think tape loop again, it is always turning). so when you hit play it will not be the same start point every time. instead it will always be a random and unpredictable point, unless you get really used to it i guess. 

i have also added a variable, resonant, analog, high pass filter that can easily self-oscillate when the resonance is set above 50%. this filter is just a working prototype i did for this device and i will not be using it again. its not at all meant to be pretty or nice sounding, it was designed to squeal and howl. its seriously not that great of a filter but i wanted something other than the usual LPF. it can be hard to control so play with it before playing live or you might piss everyone off or destroy something. if you are thinking of buying this for the filter alone DON"T, you will be disappointed! attached to it is a switchable low frequency oscillator with both square and triangle shapes. it feeds the filters cutoff and has its own depth control along with its own 1/4" output to feed external devices or to be used as a separate synth. this LFO is just alright, the triangle wave is not the same strength as the square so you will have to play around with the res and depth to get it to show up. also there is an led indicator that shows the speed but it is set to a low brightness because i kept burning them out, so it can only be seen in low light. the filter is post sampler so it only processes the result of what you have recorded, not the sampler input, but you can also plug a second instrument or line level device directly into the filter via another 1/4" input with its own volume control knob. i think this is how everything should be, separate and patchable. so in effect this is now 4 separate devices in one, a sampler, a resonance filter, an LFO, and a synth. i also added a mix control that will sweep between the clean direct sampler output and the filters output. i did this because the filter was a bit overbearing.

there is an output volume control that is pretty hot so you should always keep it low when starting out and ease it up so you don't destroy anything, especially amps. there are 2 separate mono inputs and 2 outputs to save you from having to use "Y" adapters,

there are a few circuit bends. the main one is the pitch. no its not supposed to do that. and rest are the other three switches in the center. left to right they are "crash" which is a very strong crushing, distorted, glitchy mess that also raises the volume a lot so be careful. "lo-tion" which is a sort of flangy, phasy, stuttery, slapback delay bend that at times can also get a little vocoder like. the delay only shows up at lower speeds. the "hi-tion" is very similar but way faster and distorted.

there are actually two different power switches. the samples off is setting the record play switch to the center position. the HPF / LFO power is in the back left corner with the jacks. done like this so that they could be used separately, also as a quick mute for the filter. i'm sure that one will be left on at some point but it doesn’t seem to eat batteries too bad so you should be fine if it happens.

i am also tossing in a microphone. its just a quick little thing i built into some switchcraft plugs i had around, then painted blue to be harder to lose, so i'm unimaginatively calling them "BLU". just plug it into one of the inputs and you can record in the field. simple but very handy. a picture of the guts is at the bottom so you can steal the idea.

oh the light blue color in the graphics has a bit more green in it then the photos show and both the led's are green

   * i'm sure i'm forgetting something.

UPDATE:  the issues i had with the filter and LFO have been resolved. i have added a lot more variability, the square waveform will distort the filter now which sounds great, wider range of cutoff, the led lights as it should now, resonance peak sounds nicer, etc.... i should probably make some more samples but i'd rather just get them out.

-------------- knobs --------------

pitch / speed "course"
pitch / speed "fine"
filter cutoff
filter resonance
modulation speed - LFO (also works as pitch control when used as a separate synth)
modulation depth - LFO (also works as volume control when used as a separate synth)
filter input volume - (for direct inputs)
mix - filter / original
output volume

-------------- switches --------------

record / off / play - sampler
momentary play
LFO shape - sqr / tri
crash - heavy distortion glitch bend
lo-tion - flange / slapback bend
hi-tion - phaser / distortion bend
LFO / HPF - power

-------------- jacks --------------

(2) input – mono ( any level device – mic / line)
(2) output – mono ( may also drive a pair of headphones or a small speaker )
filter input - audio in
direct LFO / synth output

-------------- accessories --------------

BLU plug microphone

samples  - - - - - - - - - - - - - -