d2k

;D cut and res now under the hands of mios aout control :) response is great :) BTW, for the aout > res connection I had to wire it direct (no resistors) to the buffer input to get the voltage range the same (0-3.3Vish) - as the 100K trimmers on the aout module didnt alter the voltage out (max was 2.summin) - that okay ye?

eheh coo - just as well it's local cos theyre pretty big old things...i've squeezed the main bits into a C64 (breadbin type) case tho, also got a core in there too...and to come the aout... so change the 47K cutoff resistors to another buffer ckt with 220k resistors? or r u sayin use the values i have in the current buffer ckt in the aout ckt? So - R_x/y = 1K, R_p = 100k? cheers

voltage was around the 3.3V mark max i think - any higher and the res just freaked out completley ;D Will post some clips once the c/v aout bidness is done :) BTW, as this res now scales up to the +3V mark, I'm assuming I need to make one of the LM's on the aout module do the same - meaning having to use the R_* resistors right...? Or can I just stick the resistorless aout c/v signal before the buffer so the voltage will be scaled up to the 3.3?

hehe, ye i worked it out after a longass google mission...:0 - res now screamin'! ;) now on to gettin the aout doin the doo (got a core hooked up and handlin midi i/o already) cheers!!!

chek the last ckt picture - u SURE it's okay? ??? ::)

well ye - u saw and said is good on the ckt a few posts bak no? power is +/- 12.... the ckt is workin, otherwise it wudnt create any res when the param is changed...

Ra and Rf both 1K as u suggested... measurements made after the buffer yes ta

0 (res min) = 0.65V 7 (res max) = 2.334V 100k trimmer doesnt effect voltage level... eh? which resistors?

okay, added the res buffer ckt (all still workin ;p) but there seems to be no dif to the res 'bite' when adjusting those 100k trimmers...just stays the same... ::)

from checkin the service manual I just see em powered from the +9 or +5

Hey Ye, it looks like its coming from the ring in that sch symbol ::) WRT powering th opamp buffer - will a biased voltage be needed - like +/- 12 or can I get away with just using the +9V from the same psu and tie the -V pin to gnd? thanks!

eheh, i've already got the main pcbs out and ousted a  few parts - still workin :) CV would be tip ye - shows it coming of 'T' (for tip ;p) in the ckt there... Cheers! BTW, I assume i can use a single TL072 for both chord and melody res buffers right?

right then, this time I musta got it?? :o ::) Thanks!

eheh okay, 'owz this now: cool! i'll get that goin (attempt to neways ;p) after these c/v bits are done :) Best

Hey... How about this: http://kitsrus.com/projects/k24.pdf ..for catching the music lsi chip logic...?

So like what I put in that last ckt then! (that extra 741 for increased res like i said in the post too) but just not as much gain - change Ra and Rf to what? See above - need 'elp inputting the right values...;p We'll leave that for now then ;p. Mebbe just a MIOS controlled digipot in place of the data dial (standard 50k pot).... was thinking tho - as each param is on a specific value (from the 0-127 range) of the pot, cudnt a lookup table be made so that when, ie, a mios button is pushed it calls that value up on the digipot (or mebbe relay pot) so I'm then ready to access the params much quicker instead of turning the pot all the time!! that make sense lol?? Cheers D

arrgh, well it was a stab in the dark ;p Is there no way to give the resonance some more ooompth then? even at max it still sounds pretty tame... ah ok, it's just it says point c 'controls cut freq' whilst b said 'vcf env'...thought both could perhaps be used for slight variations... ta BTW, Do u think it'd be possible to get 'inside' the DP935G in order to control other params which are normally only accessible from a the moody data dial pot...? I guess it'd be like controlling the SID chip in that sense...but without specific info it'd be too hard right? unless there's some way to decipher the digital signals...???

No need to apologise - i'm easily confused! :o Coo, I've made some changes to it: The ckts within the dashed lines are the additional mods. So, for 1 res c/v input (to control both chord + melody). The 741 there is to boost the res signal some more (ok?). For cutoff, both freq and env has c/v - ok again? "simply" eh :o how do I do that? with the 500R trimmer ye? Thanks for ur patience ;) BTW Herr Prof - pdf shud still b there

same ckt as what? as the one we've been dicussing since the starts of the thread?? why not just say to use the aout module 'as is' in the 1st place lol...mebbe Im missing summin??? aout balanced??? as in balanced audio connex (+/-)?midpoint?? zero external modulation?? o dear, it's got all messy now :/ if i can control it great, but a smillie wont do nefin to me gettin it implemented! thanks neways, but this is all lookin a bit long now :(

Hey Moebius great :) the lower one was an attempt to in regards to when u said: However, I am confused by all these dif voltage ranges tho - I take it this is in relation to what the input c/v is? So i need to make an aout module with 0-5V range? (assuming i use 2 opamps for these cv mods to the HT cutoff and res)... Thanks, but i'll leave all that for the minute till I get this cutoff/res c/v sorted - too much of a headscratch for me now!* Cheers * Actually, just checked that link u posted - seems I can reuse those chips for nice analog delay box ;) rather have that then a chorus!

fffs just typed a load and clicked reset instead of post!! new ckt: Can u direct me to a compander circuit i can use? - If i can improve that too then I guess I'll leave it in... Thanks

This on the right track (roughly) for adding the res c/v for instance?: Cheers!

ahhh, i thought u'd have a few ideas moebius - great stuff :) well, i think this is where some noise comes from so thought I'd bypass it neways... I'll redraw the specific parts of the ckt that I'll cut to and post back! Cheers

Heyhey Got hold of this old casio synth which came out in '87. It has a pretty basic (but rugged) sound and def worthy of some tinkering...;) As it's so old it's MIDI control implementation is standard to say the least - just note, pitch n mod up for grabs and none of the juicy stuff - which I was hoping to change... I gave casio a bell and manage to get a service manual - £10 later and they sent a photocopy version through the post. I've just scanned n PDF'ed it for those who'd like to peep... It seems theres a cpu which control the main 'music lsi' chip. But things like the vcf are a sep IC/circuit - mebbe I could add c/v control here? Anyway - any ideas would be great :) Best D

mebbe so but I have acrobat - so can file>print to PDF instead of a regular printer ;) I think there are free/shareware distillers about that do this too...if not just send me the .fpd and i'll pdf it. thanks ;) and ye the SIDs are tasty indeed!