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rvlt

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Posts posted by rvlt

  1. Some progress with my Tascam project:

    I replaced the main pcb with a self etched one. I didn't want to do it from scratch, so I just took the already existing designs, put them all on the board and connected them via ribbon cables. This also gave me the chance to try different connections easily.

    - Core8

    - DINX4

    - DOUTX4

    - Bankstick 2x

    - PSU Section from original board

    - 2x ribbon cable connectors for the two control surface boards

    I also put a Midisport 1x1 USB interface in there.

    So I did a few tests: I uploaded

    - MIDIO128 for big buttons (connected directly to DIN/DOUT) and the encoder (works)

    - scan matrix example (works with the lower buttons)

    - stribe project (leds light up).

    so far so good.

    On the hardware-side I only have to put the 7segment leds onto the pcb.

    As a programming newbie I still have to find out how to put all these functions into one program. And how to make the scan matrix work with more than 8x8...

    =====

    Uups?!?

    i can suddenly see all of Narwahl's photos, for the first time!!

    maybe it's because I've added new pics to this threat?

    anyway, great!

    post-6075-0-88489700-1331002227_thumb.jp

    post-6075-0-25373200-1331002266_thumb.jp

    post-6075-0-59581700-1331002308_thumb.jp

    post-6075-0-88049700-1331002339_thumb.jp

    post-6075-0-45231000-1331002363_thumb.jp

    post-6075-0-42061300-1331002410_thumb.jp

  2. Hey,

    I did a small PCB layout for a "ainser8" with only one 4051, since I only need 8 analog ins. Haven't etched it yet, but will do in the next few days...

    I connected CH0 of the MCP3208 to Pin 3 of the 4051, and CH1-7 to ground.

    Then I noticed in the AINSER64 schematic that CH0 is actually connected to the last one of the 4051s (IC11 / J13), not the first one.

    Does this matter at all? Or is it better to use CH7 with a single 4051 setup?

  3. 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

  4. I could add simple support for encoders (sending various CC formats including inc/dec) to the firmware.

    In long term the upcoming MIDIbox NG will support similar features, but in distance to MIDIO128 it will have better capabilities to parse and send incoming/outgoing MIDI events (including SysEx and NRPN support).

    Of course!

    Following tutorials describe the details (read the previous tutorials to understand the basics):

    http://svnmios.midibox.org/listing.php?repname=svn.mios32&path=%2Ftrunk%2Fapps%2Ftutorials%2F014_enc_relative%2F

    http://svnmios.midibox.org/listing.php?repname=svn.mios32&path=%2Ftrunk%2Fapps%2Ftutorials%2F015_enc_absolute%2F

    Best Regards, Thorsten.

    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

  5. 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

  6. 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.

    5438_cs40-1_jpg05615b8ce0b416903d9fad7da

    5440_cs40-2_jpg116f82832788ab90498d9050b

    5438_cs40-1_jpg05615b8ce0b416903d9fad7da

    5440_cs40-2_jpg116f82832788ab90498d9050b

  7. So you had no probem with your Moog Source?

    Mine has been a bitch to calibrate, and then after spending ages trying to get it right, I read in the service manual that it is not at 1v/octave?

    Funky synth tho!

    Regards

    Mike

    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.

  8. 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.

  9. 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.

    5323_black_jpgc65e59aa31b90f70028fe927bc

    5325_silver_jpgb83971f3f34c1301d51c978c2

    5327_pcb_jpgbfe725593be3e2d97ea6de4730ca

    5323_black_jpgc65e59aa31b90f70028fe927bc

    5325_silver_jpgb83971f3f34c1301d51c978c2

    5327_pcb_jpgbfe725593be3e2d97ea6de4730ca

  10. 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

  11. 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.

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