Schlagwort-Archive: dsp


a friend organized a used kurzweil k2500s, without function, but with a kdfx-card for 50 bugs. even the spare parts would bring some dozen or hundrets on eGay, if the resurrection wont happen. s on the item was the sampler, it was included with some megabytes of ram, to capture sounds from outside the synth. it was a synth workstation with scsi, floppy  disc and some pre-burned rom to create sounds from 48 voices, with several dsp-chips. but actually, not more then noise came out of the headphones and mix-out, this time.

kurzweil from rear
kurzweil on the knees

that machine had a price tag of around 8000 $, when it was available in the stores, but fully equiped it could costs something like 19.995 USD.  after 18 years, since 1996, when it was build ( born ) the inflation and process of development smashed the price, but wait. on the web some people were able to pay something like 600 or 800 bugs, some with hard-disc even for 1500$ or was it €? but first, it needs to be opened and repaired. i heard, that the owner before tried to fix the death buttons with to much „flutschi“ – the expats name for contact spray. that evil stuff killed not even the buttons, the fluid went over the whole pcb and made irregular connections between the input knobs and switches. grant!

kurzweil cables crowded
crowded cables in the kurzweil

so we opened the case carefully, without knowing, where what was placed. some ribbon cables with different sizes, some black audio or what else matter wants to flow thru that line? we would find out later, that the star-scheme of the power distribution was grown by need, so it looked pretty unsorted and far away from engineering forces. but what, where was it from … california … so its all big block here or what? removing cables, writting some hints on the ports or the cable itself should help to re-build that thing, some days later – was the plan. also checking and repairing some of the buttons needs to be done then later on.

kurzweil cabling
inner cabling from the kurzweil

but digging deeper inside the top-half of the case, extracted more and more confused coupled cables between everything. and the best, the input terminal was so retared placed, that the whole thing was needed to dis-assebled, to get in touch with the human-interface. no one during the construction thought about buttons for cents, which gonna die after some thousend or millions of clicks. so, maintanance, patience … hopefully having enuff bread-crumbs droped on the way to the front pcb, and markers, … around. the parts inside had all in all a very cheap optic, the transistors on the output-board, were such 6 cent types, you wouldnt take for your weekly macgyver-course. the ribbon cable and the connectors where fixed with metal-safeties, but that non-flexible line is worse when you want to build something extraordinary.

kurzweil job wheel
k2500s job wheel

but wait, how to clean up that mess – was the first question, when i heard about that beast. unprepared, but motivated, we digged out the pcb after some hours and due the lack of material, we decided to shower everything with hot water and some minutes of dive, we hopefully cleaned the flutschi away of the board.  kurzweil droped a lot of energy inside the psycho-acustic-algorithms, that the discussions from the hife-scene from that time, was less then a farce. the dsp and the software running on them was the fat steak of the machine, the keyboard wasnt even layed on on roses, instead, simple mdf-wood was takes as spacer.

showered input panel
kurzweil in the shower

so, without some fuel of isoprophyl-alcohol, the cleanup would be a mess, but it wasnt that harsh. it took some 15 or 20 minutes, to shower both input boards twice and then the swom in that bath for half an hour or so. drying the boards, wouldnt be a thing, but the cables were somehow sensible to that fluid. so the boards went drying on the heating for 2 weeks or more, then i would be motivated again, to put everything together with the  want and need of harmonic synthesis from that famous piece of hardware.

so, we need to be patient and come back in some days, to take part 2 of that ride.


ach wie ist dat schön, da möchte man ein externes gerät an ableton anknüppern, doch der versatz ( latenz ) mit internen instrumenten ist so auffallend groß, das guter rat teuer ist. der korg electribe offenbart nicht auf anhieb seine kapazitäten, denn diese können doch recht schnell ausgeschöpft werden. dennoch ist er mit seiner röhre ein angenehmer ruhestörer und läßt mit seinen drei dsp einigen spielraum für schmackigen sound.

ableton jedoch will auch nach einigem tuning nicht unter 150ms.latenz laufen und so kommt studio one zum zug, welches durch seine präzision und liebevolle gestaltung positiv auffällt.

im unterschied zu ableton fehlt studio one jedoch die live-ansicht, die das erstellen von pattern nur in der sequenzeransicht ermöglicht und damit im handling definitiv dahinter steht. mit einer latenz von 30ms. punktet es jedoch so weit, dass es nun beinahe unentschieden steht.

(c) chiptune on


die abtastrate ist mit 48khz nicht sonderlich hoch, der samplepufferzeigt bei einer e-mu 0404 etwa 10ms. an wenn die mukke in der daw ( digital audio workstation ) abspielt