It is hard to believe that half of a 40106 Hex Schmitt Trigger and single AD781 Sample and Hold amplifier IC can produce such a tasty lo-fi sounding effect processor. The circuit, which was developed and published by Tom Bugs on the BugBrand website is nothing short of genius with its utilization of the AD781 to sample, hold, and release a sound wave partial with each clock cycle of the 40106 oscillator. The result of such process is a very good simulation of what it sounds like to reduce the sampling rate from of a source from 44,100 Hz CD quality to 28,000 Hz NES or even lower 8,000 Hz Telephone Quality all in real-time. Impressed by the initial results and after weeks spent on research and development Steven of the Squarewave Parade asked Tom Bugs for a permission to modify the design and produce a limited run of 10 units, which are available for sale now. Each unit has been manufactured to be highly esthetically pleasing despite ultra decimating sounds under the hood. Currently each purchase also comes with a free original Suchaturnon.com design T-Shirt. Nice work Steven!
squarewave parade did a nice job on the outside but the guts look like hell. “Squarewave” you need to work on your sloppy wiring also try using some quality switchcraft/neutrik 1/4″ jacks, instead of 10 cent cheapy’s, One more thing is the use of perfboard. I’m not a fan of it. I like it for either experimenting or 3-4 component circuits. I would’ve made a PCB for this project(specially if you want to sell them).
Lovely work by Steven.
Just to note – this is doing Sample Rate Reduction only, not Bit Reduction. If you think of the waveform, Rate Reduction quantizes in the x-axis, whereas Bit Reduction would do it in the Y-axis (and require wierdy complex digital circuitry).
Great extra features by Steven and damn-good to get it battery powered.
…. Sampling rate is in Hertz (c. 44.1 kHz down to lo!)
…. Bit reduction would be 16-bits down to 1-bit etc….
very cool!! i think i will try to make one two..
i never understood what negative voltage was.. “Vee” but this circuit made me look.
so i found this explaining it to me..
thanks Tom, but you deserve all the credit, and as CM said, you are a genius. everyone should go check out bugbrand’s stuff http://www.bugbrand.co.uk/ and see for yourself. he just doesn’t always have time to make things pretty, but who cares if it sounds that good.
and thanks CM for posting this. this was a lot of fun to get together. there is a lot more stuff on the way.
a note to anyone looking to build that little board layout should realize that its a very simplified version of the “bugcrusher” and ‘downgrade’ its missing a lot of stuff. it has no modulation or preamp of any kind, so it will only work with line level devices as it is. if you want to use it with guitar or anything low level you will need to add or use a pre amp to the signal. i’m up for answering any questions you might have about it here – http://thesquarewaveparade.com/msbd/
Heh, I make perfboard and point to point circuits and sell them all the time! There are enough hazardous chemicals to deal with as it is while soldering this stuff, so why expose yourself to more trying to etch a board, ofcourse you can always order some from china! Now if you had a PCB milling machine…Thats a whole different story.
Tom, Thanks for the correction on the sample rate vs bit rate. I fixed my 16-bit to 8-bit example to reflect in Hz. Otherwise everything should be correct.
Did you mention this idea on the Benders yahoo group a few years ago? Someone posted the concept, which I think was to have a variable rate of DA conversion.. I can’t remember exactly. There was a diagram drawn, but it was only a concept. This is really cool!
Nice One to you all!
Was the benders group post something about nyquist analysing? I remember seeing something recently about that (but orig post from long ago) but I don’t think it was on such a group..
But, nah, the idea just popped into my head.!. And, the really nice thing is that there’s zero need for any of type of A/D or D/A type stuff. (I’ve done a little with micros (and aim to do more soon with Atmel devices) but they’ve made me tear my hair out before… guess its all about practice)
…2cents on perfboard vs PCB — I’ve never done anything of any complexity with perf – it just does my head in for anything other than real simple. I agree on the nasty chemicals being a pain, but for the most part PCBs rock – quick & simple to make (press’n'peel) & replicate, fewer errors and you can mount the pots direct on the board so as to minimize the chaos (& time consumption) of hookup wiring.
PS – visit http://www.analog.com and get yrself a free AD781 chip and make the circuit! Simple and very effective as published (but only really works for line level (eg effects send))
WhoopWhoop!
Ooop & when you’re at analog.com (analog devices website) you can also get a free sample of the AD633 chip and make yourself a kickass ringmodulator (again, will only really work with line levels) — have a look at http://www.musicfromouterspace.com for a simple application circuit for that (and look right through the rest of the site ‘cos it is very very great indeed!)
Thanks for suggesting Analog’s free sample offer. Does anyone have a suitable amp circuit for the mfos ring modulator at hand? Something with lm741′s maybe, as I have some of them here right now.
Anti-perfboard animosity is unfounded. Many of my custom devices have perfboard in them. If you are afraid of perf, you don’t know how to use it!
-Colin
There’s a certain level of professionalism that I would expect if I were to spent 190.00 on a pedal. One would be to definately have the circuit built on a pcb. Furthermore if your anti-PCB just means you don’t know how to use it! I can whip out anywhere from 3-5 PCB’s a night.
sorry Colin not trying to start a perf war just my personal opinion
If you are spending money on a custom pedal, isn’t the whole point that it is painstaikingly assembled by hand of some starving artist in USA and not mass produced by a chinese laborer at $1 a pop. I guess my view is just the opposite, if I’m gonna spend 190$ on it, I want the person who built it to put some serious elbo grease in making the damn thing.
I’m not trying to dis pcbs, I’m just taking sides here cause I can’t make them.
I reckon its all down to personal preference – for example, Scott Stites (one of my very favourite DIY builders – http://mypeoplepc.com/members/scottnoanh/birthofasynth/index.html) only builds with perfboard and his designs are mammoth, complex and wonderful.
But I think that if you were trying to make a batch of devices you’d go nuts (well, even more nuts perhaps!) if it was a complex perfboard.
And, PCBs still do take quite a lot of work – you do the design, press’n'peel it onto copper board, etch it, cut the boards up and drill all the freaking holes (drives you nuts – hmm, nuts coming up a lot in this diy electronics!).
Big Bug Smiles!
so Mr. Anonymous do you have a business card or examples of your work? i’ve been looking for someone with a face that i can actually talk to about ordering custom small run boards. i always prefer to help out small business owners, but its usually more expensive because they have so much riding on so few products, do to the fact that most of the time its just one person behind it all regardless of what others might think, do or say.
and the professionalism comes with things like warranties that prove i stand behind my work. my ability to actually reply to people’s questions, concerns and wants in a timely manner without any sort of shitty attitude, and my reputation which is of course just getting started. things like that! whether or not something is built on stripboard ( which is actually what i used ) or pcb isn’t going to effect the product if you did a good job building and laying it out. i suppose by your logic then point to point construction is not professional either?
thanks for mentioning the free sample thing Tom i forgot about that, i hope Gijs comes back and reads this.
sorry but i feel i need to point out that you also get a free shirt and free insured shipping anywhere in the world, on top of that is a big paypal fee cut out of my end.
pedal or pcb, i think that downgrade looks wicked. i bet it sounds even better. I wish mine looked like that!!!
http://www.frostwave.com/sonicalienator/
I can’t tell if the previous poster was attempting to make a suggestion or is just a spam bot.
Probably a suggested link by a fan of Paul Perry’s pedals
You’re all a bunch of creative geniuses…everyone one of you!
[...] bit reduction [...]
[...] could just go on and on, and on…. so here’s a link of something i should just build: http://www.getlofi.com/?p=626 i need one of these: [...]
[...] …this could just go on and on, and on…. so here’s a link of something i should just build: http://www.getlofi.com/?p=626 i need one of these: [...]
Getting hard to get those ad781s. Is there another ic that can be replaced?
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