rvlt

today I played around with the pots a bit more: tried different pots and values (1k, 10k), connected only one pot at a time, inside/outside the case… and after reading your post now my conclusion is the same: must definitely use the AINSER64 if I want to use analog pots with the LPC17. Ok, installing xcode right now …. :thumbsup: Thank you Thorsten! Lars

Support for encoders would be great, and quite useful. I will definitely dive into programming, that was one of the reasons I built the new core, but I guess it will take some time before I come up with something useful. Speaking of Midio128, right now I experience some heavy jittering with the 8 analog pots, constant bombardement with values (like 3-4 messages every second), some are jittering around a certain value, and sometimes it's all over the place. I used 10k pots with the 100nF capacitors, and cables are quite short (ca. 12cm)... I guess it's some kind of grounding issue. Have to try some things over the weekend... Best regards, Lars

Hello everyone, I'm in the middle of building a small Midi controller with the Midio128 V3 / LPC17. It will feature the standard control surface parts (LCD, 6x buttons + 1x encoder), 8x analog pots and three switches (via a self-etched DINX2). I would really like to add one or two encoders (to send standard midi CCs), but I guess that's not possible with the current Midio128, right? TK, do you have plans to implement this into Midio128, or is this "reserved" for a possible MB64e for MIOS32 in the future? Don't know what the "road map" for MIOS32 is. Or to ask the other way round: Is there a way to use encoders with MIOS32 / LPC17 ? Best regards, Lars

Hey, is anyone able to see photos or attachments in this thread? I'm logged in but can't see anything, but maybe I'm doing something wrong. I grabbed a MM-RC off ebay for cheap and would like to mess around with it, and the schematic and the pics would really be useful as a starting point..

Got my parcel yesterday. Thanks Wilba!!!!!

although I found another solution (reed relays, see below), I had some time today to do some tests (midibox cv <> cs40m). 1. I double checked internal cv-calibration of cs40, but it was spot on measured at cv-out: C2 = 250mV C3 = 500mV C4 = 1V C5 = 2V 2. I tuned the cs40 again, got a pretty stable tuning 3. I calibrated the mb-cv according to the manual (Hz/V, max setting = 10,24V, then fine-tuned the 1V-setting to get exactly 1000mV) 4. then I measured the cv-out at the interface: C2 = 247mV C3 = 498mV C4 = 1V C5 = 2.01V I connected mbcv to the synth and, as one might expect, C2 & C3 were too low (about 40-50 cent) and C5 too high. a difference of 3mV doesn't seem much, but it is really noticeable. 5. I tried messing around with the onboard trimmer, but the behavior always stayed the same: "low keys too low" and "high keys too high". 6. I re-adjusted mbcv and connected my ms20 (starts at 1V, 2V, 4V, 8V), and tracking was perfect. hmm..?? 7. I connected a friends' kenton pro solo to the cs40, which has a "fine tune" and "scale adjust" parameter. finally it gave me a good tracking, it was off by a few cents, but that doesn't matter.. so.... I think the best solution would be a software fine tune & scale adjust that would allow us to adjust the "steepness" (?) and offset of the output curve. But I would really like to hear the results from other cs-users, maybe my cs40 is just funky and other synths work just fine. ==== in my case I found another solution: I had a midio128 (with reed-relays) installed in my juno 6. I put that in my cs40 and will install a mungo-enterprises interface instead. works perfectly, attached some pics.. ==== @sonicwarrior: if you decide to make the converter-pcb, I think I'll take one or two, I could use that for other stuff.

Hey Mike, at least the source I have (actually, it belongs to a friend) works with 1V/Oct. I checked with the owner's manual page 49: "As an input, the CV jack sends any control voltage received to the oscillators, which track this incoming voltage at 1 volt / octave." but ... I had massive tuning problems before: as soon as I touched the case, the tuning got crazy. It took me hours to fix it, it was a loose contact at U12: The source I had was modded, someone put a resistor and a 1M trim between R65 and U12 pin 1. Don't know what this was for, but I left it in. I resoldered the contact between the trim and U12 and tuning was stable again. so, maybe that mod is necessary to get a 1V/Oct response? Don't know.. === Ah, another thing comes to my mind: I calibrated two moog prodigys (my own and the one from a friend), and both synths had tuning problems due to bad CA3046s in the oscillator section (the ones responsible for temperature adjustment). Maybe you could try to put new 3046 in your source (U26 + U34) and see if that helps. ok, best regards, rvlt.

Ok, here's a list of synths that work with the midibox cv with no problem: - Moog Prodigy - Moog Source - Moog Rogue - Korg MS-10 - Korg MS-20 - Korg X-911 - Roland SH-101 - Sequential Circuits Pro One so, generally speaking, I guess all standard 1V/Oct and Hz/V (Korg) should be fine. Keep in mind that ... - it's a good idea to calibrate your synths before connecting it to your cv-interface. I did that with all of above (what a nightmare!), but it was worth it. - if you want to use synths with S-Trigger (Moog, Korg ..), you need to add a small circuit to the gate-out to make i work ==== I slightly missed a software fine tune control. Would be really helpful to adjust the mb-cv tuning to the internal keyboard so that you don't have to retune everytime you switch between mbcv and "real" playing. maybe in future software release?? ==== the only synths I couldn't get to work with mbcv were two yamahas (CS-5 and CS-40m). They have a "kind of" Hz/V behavior (CV doubles with every octave), but control voltage starts real low (C1 = 250mV, C2 = 500mV, C3 = 1V ..), whereas Korg synths start at C1=1V, C2=2V, C3=4V ... I don't know, maybe the resolution of max525 is too low in that range? maybe someone could enlighten me.. cheers, rvlt.

Hi everybody, I built two midibox cv interfaces with the "all-in-one" pcb that sonicwarrior offered a few weeks ago. I think I share my experiences since there are a few traps you might fall into: 1. The print on top of the pcb for the LM385 is wrong! you have to turn the LM385 180 degrees, or you won't get 2,5V .. 2. Since I used a LM385 (2,5V) instead of a MAX6007 (2,048V) I had to adjust resistor values for all R_y: 2,7k worked for me. 3. R6 is missing in the BOM. It's 2,2k. 4. C11 is listed twice in the BOM. Should be 100N (not 330N). 5. You have to put a jumper at J3 if you don't have a separate 5V supply. 6. There are two resistor networks (RN1 + RN2) around IC5. For RN1 the pin-1 marking is missing: Pin 1 is point away from the PIC. I got a really weird menu navigation when I got this wrong first .. ====== I have attached a few pics: the black one is mine, I added a Yusynth clock divider and a gate-trigger converter (small breadboard in the back) to trigger my moog & ms20. the silver one is for a friend: no clock divider, but a much nicer front panel (schaeffer)... cheers, rvlt.

Ah, one more thing: Before I built the reed relay board, I thought I could just use an interface which "hijacks" or "mimics" the signals from the 8x8 scanning matrix (without having to use a relay for every single key). So I tried the UMR from highly liquid, but unfortunately it didn't work. In theory such "emulator" could work, but in this case the scanning speed an pulselengths were different, so had to go the expensive route... ---- I don't have a camera right now, but I could take some pics of the relay-board in the next few days if you are interested cheers

Hey Sasha, just wanted to let you know I midified my Roland Juno 6 with a midibox circuit and reed relays. I "cloned" the breadboard layout which TK used to midify a Korg PS3000, I only used more relays (61 at all). It works (well, at least 98% of the time, there is some strange behavior when you press certain combinations of keys, but anyway...), but ... ... it was a lot of work and expensive! I paid well above 100,- euros. As you said before, reed relays aren't cheap. If I had a Juno 60 with a DCB port, I would certainly go for a DCB interface. There's one from engineers@work which costs about 89,- euros. If it works as advertised, you can't go wrong with it. Although your project looks really interesting, it's always sad to see working juno got ripped apart. They are such good sounding and well layout synths... Anyway, happy modding and let us know the results. cheers.