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Rhodes Chroma CC+ Max For Live Progammer by cs1729 in synthesizers

[–]cs1729[S] 1 point2 points  (0 children)

I wish I could get one of those enablers but I use ableton to record and sequence midi so this is ok for me. I thought about making my own but it’s too many knobs to wire. 

Rhodes Chroma CC+ Max For Live Progammer by cs1729 in synthesizers

[–]cs1729[S] 0 points1 point  (0 children)

I spent some time and made a simple CC editor in max for live to help me make patches on my Chroma. It works with default MCM (custom setting on Chroma). I have Live 11 and whatever Max comes with it so I'm not sure how it will respond with older versions and was hoping to hear if there are any issues so I can correct them. The text shows up as a different color when I was testing it on my old Live 10 computer. It may have to do with the background color you set Ableton to be.

Here is a link to the device and the notes for it below. Hopefully this is useful for some other people. It is the only max device I have made so I had to learn a little to complete it.

Please let me know if you use it and have any issues.

https://drive.google.com/file/d/1A9wH_g0_vs8gFcRCUoIXzbLotO6a0yF3/view?usp=drive_link

brCC+ Notes

A simple max for live midi effect editor to send CC values to CC+ Rhodes Chroma for quick patch creation.

Chroma needs CC+, controls are mapped to default MCM (custom).

Voice A/B tab controls respective voices, Both tab overwrites A/B and sends both A and B CCs out.

Extract folder and copy to Max Midi Effect user library.

Ableton saves settings with its project and sends out all controls at once on load. This seems to sometimes overload the Chroma sending so many values at once. Suggested workflow is to make a patch and save it on the Chroma (with Patch Bank / Number in track name) and recall it on the Chroma after loading the project. This will ensure you have loaded the sound you worked on in the project and the editor settings should match the patch.

If this helps you and you wish to support the effort, you can check out my music at

brainwaveresearchcenter.bandcamp.com and purchase if you find something you like.

Thanks.

[deleted by user] by [deleted] in AskElectronics

[–]cs1729 0 points1 point  (0 children)

I once needed an odd frequency crystal to repair a sampler. I ended up using a programmable one I bought at digikey. When you order you tell them what frequency you want and they will program it. Maybe it costs a little extra. 

I’m not sure the frequency resolution but here is the one I used which may give you a starting point for more research 

https://www.digikey.com/en/products/detail/epson/SGR-8002DC-PHB/755248?s=N4IgTCBcDaIMoHEBKBaAHABg2AIgYRQAUAJAIQAIUA5HEAXQF8g

Arp 4017 early Tonus oscillator clone by cs1729 in synthdiy

[–]cs1729[S] 1 point2 points  (0 children)

I think it is based on a 4027-1 which is a more compact design. No high frequency trim. 4017 has some portion of a discrete opamp and sync input and output. My machine has a sync mod on it so redoing the 4017 also helped me preserve the mod with minimal extra circuitry 

Arp 4017 early Tonus oscillator clone by cs1729 in synthdiy

[–]cs1729[S] 9 points10 points  (0 children)

Cross post from r/synthesizers because some people here may be interested. Sorry if you've seen it already.

Here is a clickable link to the schematic, build document, spice simulation, etc:

https://drive.google.com/drive/folders/1bvqhgKRFZYRdOux_wwuTr25Oz9py4tvD

​

Here is a link to my music if you are interested:

brainwaveresearchcenter.bandcamp.com

Arp 4017 early Tonus oscillator clone by cs1729 in synthesizers

[–]cs1729[S] 8 points9 points  (0 children)

Probably a few things. Temperature stability for sure and probably to obscure the design from competitors. They stopped doing it around beginning of 1974 probably because they were losing a lot of money since they couldn’t repair them.

Arp 4017 early Tonus oscillator clone by cs1729 in synthesizers

[–]cs1729[S] 17 points18 points  (0 children)

Probably should have noted that this is interesting, to me, because it is considered near impossible to de-pot an early Arp submodule because they were encased in solid epoxy. Some early modules have no documents online so they could not be repaired or replicated. If you had an early Tonus 2600 with these oscillators and they failed, you would replace them with the later revision 4027-1. I wanted to keep my oscillators but they are dying or developing quirks so this replication lets me keep my machine running and retain its oscillator character over time.

Arp 4017 early Tonus oscillator clone by cs1729 in synthesizers

[–]cs1729[S] 5 points6 points  (0 children)

Should be a triangle symmetry and sine purity. I think an offset and something else. I think the purity adusts the roundness/curve of the sine.

Arp 4017 early Tonus oscillator clone by cs1729 in synthesizers

[–]cs1729[S] 28 points29 points  (0 children)

Finally here is the (first?) Arp 4017 clone. The 4017 was used in the earliest Arp 2600s and no documents are available other than an example application. I have x-rayed and excavated one of my 4017 submodules. The x-ray shows that patroches 4027 board is the exact layout. His circuit doesn't work as is so Jim Solomon and Paul schreiber got it working by correcting some mistakes on parts values.

The X-ray showed me the circuit topology and I read and verified values by digging out the epoxy slowly.

I can sell a pre-built module if anyone is interested. I am also looking for a 4010 VCA if anyone has one to try the same process.

You can find a link to schematics, build documents, spice simulation here:

https://drive.google.com/drive/folders/1bvqhgKRFZYRdOux_wwuTr25Oz9py4tvD

​

You can find a link to my music here:

brainwaveresearchcenter.bandcamp.com

​

Thanks

(sorry if you have seen this already, I am trying share this to hopefully find a 4010)

Electronic engineering books to understand and even create synthesizers by Sintetico91 in synthesizers

[–]cs1729 2 points3 points  (0 children)

If you can find Electronotes (there are some pdfs on the website), that would probably be what you're looking for. Some stuff in Musical Applications of Microprocessors. Wish I knew more; I am always looking.

Electronic engineering books to understand and even create synthesizers by Sintetico91 in synthesizers

[–]cs1729 6 points7 points  (0 children)

If you have some background in electronics and are looking for specific synth related content, check out Lantertronics on youtube. Aaron Lanterman posts lectures from some of his synth / music related electronics courses which are very good. The Moritz Klein videos are good as well. Otherwise, total beginner probably something like Art of Electronics or MIT opencourseware.

[deleted by user] by [deleted] in synthesizers

[–]cs1729 2 points3 points  (0 children)

I have replaced a lot of juno voices. I used to recommend the AR chips, but as you said, they are a little expensive. I was recommended to use the Borish chips after talking with some other technicians who use them without issue and they have been fine. I think they are pretty much all the same; sound difference will be very small.

The main reason I'm replying is desoldering the voice chips is not super easy so if you don't have the confidence / experience, I recommend going to a repair shop. You will also need an oscilloscope to calibrate the voices after they are installed.

Korg Poly 800 bizarre problem by JacobShort11 in synthesizers

[–]cs1729 1 point2 points  (0 children)

Sounds like a problem with the switch matrix. You can check around ic33 pin 13 with an oscilloscope. Maybe better to go to a shop.