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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Fri Apr 12, 2013 3:51 am Post subject:
Painless Aftertouch Mod for MkIII Odyssey |
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I've had a long Interlink FSR laying around for ages, so I thought I'd do something with it... and share.
I decided to add LFO aftertouch to my MKIII Odyssey (I'll probably get round to different routing configurations later).
Cost - Under £20!!
What you need:
A Long Interlink FSR (620mm x 15mm)
Aluminium Angle (15mm x 565mm)
Self Adhesive Neoprene rubber strip (3mm x 15mm)
Nuts, bolts, washers for mounting.
What to do:
Drill a 4mm hole halfway up the alu angle, and 20mm in from the left and right edge (See pic 1)
CAREFULLY remove the keybed from the Odyssey and drill matching holes (15mm up from the bottom "lip")
Clean the top of the alu angle with isopropyl alcohol to remove any grease etc and attach the (self adhesive) FSR - Note the orientation in pic 2.
Apply the 3mm thick neoprene strip to the top of the FSR, and cut to match the length of the alu angle as in pic 3.
Bolt the FSR assembly to the ARP keybed and see if the rectangular key stop JUST rests on the neoprene when depressed - you can get away with a very slight gap, but you may have to file the hole in the angle to allow adjustment... I got plain lucky
Put the keybed back in the Odyssey
Put two flying leads onto the FSR (how you go about this is up to you, but I soldered an 8 pin DIL socket onto some vero board, took the flying leads off pins 1 & 2 and just inserted the end of the FSR into the DIL socket (it's nice and tight). You'll need to CAREFULLY bend the end of the FSR round as there's not much room there!
Solder one lead to the LFO output (you'll see a single connector on the lower middle PCB with a GREEN wire going to PCB 1 - that's the LFO out). Solder the other lead to the track where the WHITE wire of the PPC connector is - top of PCB 1.
Close the panel, fire up - Hey Presto, LFO modulation via aftertouch.
As I mentioned earlier, you may need to adjust the hight of the FSR to suit.
The whole thing took just over an hour to make and install - It helps if you get everything ready in advance... coffee, relaxing music, a lock on the door...
EDIT... the pics uploaded in reverse order
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frequencycentral
Joined: May 25, 2008 Posts: 186 Location: UK
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Sat Apr 13, 2013 5:00 am Post subject:
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I'm just running up a PCB (circuit copied from the Korg Kronos) for a "proper" aftertouch interface - It gives variable offset and gain.
I'll make another assembly for my modular, and hopefully I'll be able to control a few VCA's with it... may be interesting.
And who knows... maybe I'll eventually be able to fix the aftertouch on my Fantom X (I've always needed severe pressure to get it to work). |
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Posted: Mon Apr 22, 2013 2:21 pm Post subject:
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I've just been wanting to do the same thing, but to my Mk1 Oddy. My Oddy was pretty well chopped up by it's first owner, so I don't mind making more useful mods to it.
I've sort of been inspired by recent commercial oddy aftertouch solutions I've seen on ebay and elsewhere, and also by a photo I once saw of Arps in-house testing Oddy, which they had totally modified and modularized with after touch and so on.
Have u seen this aftertouch kit? It has really nice routing.
I'll definitely be following your progress if u decide to keep posting about it as I'd like to follow your example, and also try to incorporate the routings from the link. |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Mon Apr 22, 2013 11:44 pm Post subject:
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ericcoleridge wrote: |
Have u seen this aftertouch kit? It has really nice routing.
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That's the kit that inspired me I've drawn up a schematic that will give me LFO Mod to VCO 1, VCO 1&2 and VCF, direct CV from the FSR (via adjustable slew for smoothing) to VCO 2, VCO 1&2, and VCF - not sure at the moment if I want or need VCA modulation.
I'm currently trying to find pots that are small enough to fit behind the front edge panel - My usual 16mm Alphas are too deep so I need to get my thinking cap on. |
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ericcoleridge
Joined: Jan 16, 2007 Posts: 889 Location: NYC
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Wed Apr 24, 2013 11:47 pm Post subject:
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Thanks Eric... They look perfect for the job |
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delayed
Joined: Jun 24, 2008 Posts: 130 Location: TN
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Posted: Thu Apr 25, 2013 12:13 am Post subject:
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neat, i would not mind putting this in a white face. |
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camelneck
Joined: Sep 27, 2008 Posts: 68 Location: KY (USA)
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Posted: Mon May 06, 2013 5:58 pm Post subject:
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Hi Andy,
This is awesome news. I was exploring this idea about 2 years ago, but never followed up on it. I would love to add Aftertouch Sensors to my ARP Odyssey and replace the Aftertouch sensor on my ARP Quadra, which has lost almost all of its sensitivity. If it works well, I might even add aftertouch sensors to my ARP Axxe, Solus, & Explorer.
In fact, I have a couple of the original ARP aftertouch sensors, but they no longer work due to the resistive strip in the sensor losing its sensitivity. (I obtained these non-working sensors from my Pro-Soloist and Pro-DGX after I replaced them with 2 NOS ARP aftertouch sensors that I bought on ebay about 6 years ago.) Nevertheless, I'm sure I could replace the old resistive strip glued to the original aluminum bars with the Interlink FSR on both of the defective sensor bars and create a couple of working touch sensors for my Odyssey and Quadra for starters.
I do have three questions about the parts (specifications, cost, and availability) that you used:
1) Where did you buy the Interlink FSR and how much did it cost?
2) Does the Interlink FSR come in different sizes depending upon the desired resistance range (ohms) and the amount of pressure (lbs or Newtons) that you intend to apply to it? If so, please supply electrical specifications for the FSR that you used in your Odyssey?
3) Where did you purchase the Interlink FSR?
In fact, if you could provide us with a web link to a store where we could purchase and read the specs for the Interlink FSR, this would suffice for both Questions #2 & #3.
4) Where did you get your strip of neoprene and how thick was it?
FWIW, the photo that you provided of your homemade AfterTouch sensor looks almost identical to an original ARP touch sensor. The main difference is the fact that you used a flat aluminum angle instead of an Aluminum bar that was designed especially for Pratt-Read keyboards. However, this is probably no big deal.
ARP used a strip of felt to cover the resistor (FSR) strip instead of neoprene, so I'm sure one could probably use a thick strip instead of the neoprene (whichever is easier to find). Unless I'm able to reuse the original felt strip, I'll probably use a neoprene strip (if I can find a strip of it that is the right thickness) since you had good results with it.
Thanks again for the great info!
PS.
When I looked into this idea about 2 years ago I was planning to use some Force Sensing Resistor (FSR) strips that I saw in a Jameco catalog. The Jameco FSR I saw looked very similar to the Interlink FSR shown in the photo that you provided. (I think the ones that Jameco had were called Flexiforce FSR's or something like that. I'm not sure if they are still available.). Last edited by camelneck on Mon May 06, 2013 6:49 pm; edited 1 time in total |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
Audio files: 11
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Posted: Mon May 06, 2013 6:23 pm Post subject:
Painless Aftertouch Mod for MkIII Odyssey Subject description: FSR Source |
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Completely awesome idea. Nice work!
Looks like you can find Interlink FSRs at Digi-Key. Here's the 24" model
http://www.digikey.com/product-detail/en/30-61710/1027-1003-ND/2476472
Not bad at about $15.
Tim (afterouch afterthought) Servo |
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camelneck
Joined: Sep 27, 2008 Posts: 68 Location: KY (USA)
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Posted: Mon May 06, 2013 7:06 pm Post subject:
Re: Painless Aftertouch Mod for MkIII Odyssey Subject description: FSR Source |
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Ahoy Tim,
I haven't talked to you in awhile. Thanks alot for the info.
If I can revive my 2 dead touch sensors for $30, I'll be thrilled to death.
I hope it will work with my Quadra also and then I'll have 3 totally refurbished touch sensors.
In the old Solus, which was the pre-cursor to the Pro-Soloist and Pro-DGX, ARP had originally used a graphite-laced foam, but these touch sensors failed after a few months use. They then went to this rather, cheap and clever solution and some of these sensors are still operational some 40 years later.
The fact that the Soloist family of synths were the first synths to have a patented aftertouch system made them a very hot commodity. In fact, 8 to 10 years after their introduction, the Japanese company Teisco purchased these same touch sensors from ARP and installed them in their preset synths. (I'm sure they could have made their own but ARP had a patent that covered them.) |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Tue May 07, 2013 3:42 am Post subject:
Re: Painless Aftertouch Mod for MkIII Odyssey Subject description: FSR Source |
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Thank you : )
That's exactly where I got mine from - unfortunately 24" is the longest FSR available, but I don't see a problem using two in parallel (in fact, that's what I'll be trying on my Fantom X).
@ Camelneck - The neoprene strip was off good 'ole ebay (self adhesive 15mm wide x 3mm thick), it's cheap and readily available.
To be honest I didn't worry about resistive values or pressure requirements... I just tried it, and it worked. As it stands, it feels as good as any synth aftertouch I have
I'll get back once I've tried out the "full" interface... just waiting for the 9mm 100k pots. |
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tommym
Joined: Sep 17, 2015 Posts: 1 Location: NY, NY, USA
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Posted: Thu Sep 17, 2015 4:30 pm Post subject:
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AndyR1960 wrote: | I'm just running up a PCB (circuit copied from the Korg Kronos) for a "proper" aftertouch interface - It gives variable offset and gain.
I'll make another assembly for my modular, and hopefully I'll be able to control a few VCA's with it... may be interesting.
And who knows... maybe I'll eventually be able to fix the aftertouch on my Fantom X (I've always needed severe pressure to get it to work). |
My XV-88 is also almost impossible to pressure hard enough to trigger the aftertouch. I read somewhere that a capacitor has to be replaced with one of a different value. I can't find the info, but I think there was a '35' somewhere in it; either the specific component, or the replacement's value. |
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