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ChromaTalk Archives: August 2013

Re: 0027 update

Go to first message in thread, July 2013

Michael McInnis [21030027]

Well, 0027 is now hot rodded with a CC+ & new power supply.

I was able to source a Quadra slider and replace the broken pitch control. AS Paul [21030230] had suggested, a 100k replacement works fine in that circuit.

One of the remaining two non-working cards is now fixed, thanks to Rob at New England Analog. He is working on the last card, which is the last outstanding issue.

I brought the instrument into the studio last night for the first time after having the work done, hooked it up, set up an iPad to use the TouchOSC template and was off. Needless to say, I got very little sleep last night!

Thanks to everyone on the list for all their help, invention, and passion. You make owning and resurrecting these wonderful instruments a fun adventure.

And to the the original design team, thanks for such a deep & musical sounding synth...I am blown away!



Go to next message in thread, September 2013

Leons Chroma iPad Editor...

Dryden Chambers

Anyone running the iPad editor on a iPad Mk I btw ? They are pretty cheap these days and was thinking about getting one just for the Chroma to run touchosc and Leon's editor profile.

btw Leon [21010301], are still expecting a update to the editor ?

Cheers, DC

Matrix [21030220]

I am. I created the original on the iPad 1. It works great.

Dryden Chambers

Thanks for the info M. What's the cheapest iPad Midi connection option out there, is it still the camera connection kit and cheap break out cable off Amazon/Ebay ? DC

ps What Matrix, your not editing your Chroma on the Retina display ? : )

Matrix [21030220]

I believe so. Just search on Amazon or eBay for prices. I've been waiting for the iPad Mini to get Retina. :) Hopefully it will come in the next release.

David Clarke [21030085++]

For quite a whie now, the CC+ has had the ability to send all of its current patch settings to an editor via MIDI CC messages. In the older firmware releases, those CC messages would be requested via SYSEX.

The most recent firmware update [217] added a MIDI talkback feature that allowed the current patch parameters to automatically be sent out via MIDI CC when a patch change was made on the Chroma.

Following up on the general iPad editor discussion - has anyone created a bi-direction MIDI configuration for the editor such that it could see the 'current' patch settings from the Chroma?

Arp Branded Voice Card Filter Issue

Michael McInnis [21030027]

I am having an issue with one voice card that is similar to one posted about in April of this year by Philippe [21010227] [click noise on envelope].

Philippe was experiencing a click on attack on one board when filter resonance was high. I am experiencing a similar problem of a click on release with filter resonance at 6 or 7.

It was suggested to me that there was a documented circuit modification to address this issue, but I have searched the Chroma site and not found it.

Philippe, did you ever resolve your problem?



Philippe [21010227]

I did, it is a very simple solution and I can tell you what it was when I'm back home in 10 days.

Michael McInnis [21030027]

Philippe, are you back?



Philippe [21010227]

Hi Michael,

Sorry to reply later than expected, busy times... Anyway, I am not 100% sure yet as my Chroma is covered with other gear and I cannot access that card at the moment but I believe the issue was simply that C43 & C44 were missing on my board as strange as it may seem. I can confirm this in a few weeks. I believe they were 0.1uF capacitors. Just change those by new ones and your problem might be solved.


Go to next message in thread, September 2013

MAX/Mira bi-directional iPad editor

Brian McCully [21030361]

Hi All,

Hopefully this post is getting to the correct address...I haven't posted in a while.

An exciting product from Cycling74 was recently released for the iPad which mirrors ("mira's") a MAX patcher window or parts within the patcher window (which can be tabbed through, for multiple screen sets).

Mira: Touch Controller For Max « Cycling 74

I've been holding off purchasing an iPad as the touch latency kind of bothers me, and no bi-directional software was available. Now I bought a new iPad just to use it, and it works quite well. To start, I had created a JX-8P editor a year or more ago, and all I had to do was add (draw) Mira 'frames' around any set of screen controllers (knobs, buttons, sliders, etc.) and those controllers show up on the iPad screen. Now a set of (e.g.) 4 ADSR sliders are all multi-finger accessible and the values (slider positions) are all 'pre-loaded' instead of zero'd. One can draw a Mira frame around a 2nd set of ADSR sliders and simply tab to that screen. And/or draw a Mira frame around them all...etc etc - it's up to the creator how one wants the screen controls to be laid out.

There is a minimal latency, and a few quirks, but overall I'm really impressed with the concept and simple interface. Works via wi-fi - I mounted my iPad on a mic stand next to a synth stack and it's really quite accessible - no wires.

Next project is finishing the screen UI for the JX-8P editor, then probably creating a Nord Stage EX editor as a warm up to a Chroma Editor, as the Nord sends out all CC's for its parameter values in a similar fashion to the CC+. Hopefully functionally it will all be quick to construct, but tweaking each UI screen will probably take a bit extra.

No more mousing through a Mac synth editor - which to me gets -really- boring. Editing multiple parameters at once is going to be really cool - via definable x/y fields, or multi-slider swipes, or simply adjacent sliders. Obviously less wear and tear on the hardware too.

One gotcha is the cost of Mira ~ $50. Currently it only works on Mac, but a PC version is in beta. You don't have to have MAX loaded on your Mac or PC, as one can create a stand-alone run-time MAX app for distribution, but the Mira app would be required to interface with the iPad.

That's the good news for now...cheers, - Brian

Dryden Chambers

Looks nice. Will a mac have to be hooked up the setup for this to work (a major plus for Leon's editor that it doesn't).

Brian McCully [21030361]

Yes, the Mac (or soon to be PC version) is 'hooked up' via wireless, and does need to be running a MAX 'patcher' containing Mira 'frames' (i.e. the iPad windows). I'm not sure how the other iPad editors communicate, but I kind of assumed that a Mac or PC would be somehow found in the control chain.

The MAX application, in regards to using MIDI only, is generally not very processor-intensive regardless, and can/does easily run in the background of sequencing, DAW's, etc. I use MAX patchers as control interfaces for MIDI Stick (12 MIDI channels), and for combined routing for external drum triggers in a larger VDrum kit that contains a TD-20, TD-10 and Handsonic with additional TMC-6 and Alesis Trigger IO triggers. MAX is an extremely handy MIDI do-all. The great thing about this MIRA app is that the typical MAX MIDI handles are all set - other than praying that the wireless set-up works (it did so first time, and has continued to), it's been plug and play so far. I just need to majorly brush up on my rusty MAX programming chops... ;>)

Dryden Chambers

not a big fan of having mc or pc, AND iPad in a chain to edit any synth, just too many resources tied up. The app looks nice and bidirectional is also cool, but I will probably stick to Leon's editor for the Chroma which after setup only needs a Ipad.

Speaking of which Leon, ahem, might we see the finished version of the Chroma editor this year ?, pretty please with sugar : )

Brian McCully [21030361]

The iPad is not in the chain. The synth is linked to MAX running on the Mac or Pc, and the iPad is linked to MAX. iPad<->Mac/PC running MAX<->MIDI<->synth Not sure how many studios would have a Chroma without a nearby Mac/PC...? Bi-directionality is a major plus for editing, as there's no guesswork as to what the exact starting values are, which was the main purpose for my post. If the TouchOSC iPad implementations were bi-directional I probably wouldn't bother with this.

Leon van der Sangen [21010301]

Hi Brain,

Thanks for using my editor. I lost my interest in synth's last year. And sold nearly everything including the chroma. I still think this is one of the best sounding synth's. I will try to help you but you need to tell me wich parameter does not function and you have to give me the exact parameter rangen from the chroma. If you have specific wiches i will try to make it. I will send them directly to your emailadress so you can test them. If the version is good you can donate it to the chromasite.

For instance i can make knobs for exact pitch like 2", 4" ,8", and so on for each chanal. So tuning off both is easy.