electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
 Forum index » DIY Hardware and Software
Painless Aftertouch Mod for MkIII Odyssey
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [12 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
AndyR1960



Joined: Feb 16, 2007
Posts: 275
Location: Manchester UK
Audio files: 5

PostPosted: Fri Apr 12, 2013 3:51 am    Post subject: Painless Aftertouch Mod for MkIII Odyssey Reply with quote  Mark this post and the followings unread

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 Smile

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... Wink

EDIT... Rolling Eyes the pics uploaded in reverse order Rolling Eyes


SAM_0133.JPG
 Description:
 Filesize:  135.73 KB
 Viewed:  35 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

SAM_0133.JPG



SAM_0127.JPG
 Description:
 Filesize:  124.3 KB
 Viewed:  34 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

SAM_0127.JPG



SAM_0123.JPG
 Description:
 Filesize:  110.21 KB
 Viewed:  33 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

SAM_0123.JPG



SAM_0122.JPG
 Description:
 Filesize:  132.52 KB
 Viewed:  34 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

SAM_0122.JPG


Back to top
View user's profile Send private message
frequencycentral



Joined: May 25, 2008
Posts: 186
Location: UK

PostPosted: Sat Apr 13, 2013 4:06 am    Post subject: Reply with quote  Mark this post and the followings unread

That's clever!
_________________
http://www.frequencycentral.co.uk/
Back to top
View user's profile Send private message
AndyR1960



Joined: Feb 16, 2007
Posts: 275
Location: Manchester UK
Audio files: 5

PostPosted: Sat Apr 13, 2013 5:00 am    Post subject: Reply with quote  Mark this post and the followings unread

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).
Back to top
View user's profile Send private message
ericcoleridge



Joined: Jan 16, 2007
Posts: 885
Location: NYC

PostPosted: Mon Apr 22, 2013 2:21 pm    Post subject: Reply with quote  Mark this post and the followings unread

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.
Back to top
View user's profile Send private message
AndyR1960



Joined: Feb 16, 2007
Posts: 275
Location: Manchester UK
Audio files: 5

PostPosted: Mon Apr 22, 2013 11:44 pm    Post subject: Reply with quote  Mark this post and the followings unread

ericcoleridge wrote:


Have u seen this aftertouch kit? It has really nice routing.


That's the kit that inspired me Smile 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.
Back to top
View user's profile Send private message
ericcoleridge



Joined: Jan 16, 2007
Posts: 885
Location: NYC

PostPosted: Wed Apr 24, 2013 4:01 pm    Post subject: Reply with quote  Mark this post and the followings unread

I have a dwindling stock of 9mm alphas from Futurlec that I've been using for years; but I've bought these inexpensive 6mm (?) Bournes-type made-in-china pots from ebay when I need to fit into super small spaces:
http://www.ebay.com/itm/120932881230?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649
Back to top
View user's profile Send private message
AndyR1960



Joined: Feb 16, 2007
Posts: 275
Location: Manchester UK
Audio files: 5

PostPosted: Wed Apr 24, 2013 11:47 pm    Post subject: Reply with quote  Mark this post and the followings unread

ericcoleridge wrote:
but I've bought these inexpensive 6mm (?) Bournes-type made-in-china pots from ebay when I need to fit into super small spaces:
http://www.ebay.com/itm/120932881230?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649


Thanks Eric... They look perfect for the job Very Happy
Back to top
View user's profile Send private message
delayed



Joined: Jun 24, 2008
Posts: 129
Location: TN

PostPosted: Thu Apr 25, 2013 12:13 am    Post subject: Reply with quote  Mark this post and the followings unread

neat, i would not mind putting this in a white face.
Back to top
View user's profile Send private message
camelneck



Joined: Sep 27, 2008
Posts: 68
Location: KY (USA)

PostPosted: Mon May 06, 2013 5:58 pm    Post subject: Reply with quote  Mark this post and the followings unread

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
Back to top
View user's profile Send private message
Tim Servo



Joined: Jul 16, 2006
Posts: 924
Location: Silicon Valley
Audio files: 11

PostPosted: Mon May 06, 2013 6:23 pm    Post subject: Painless Aftertouch Mod for MkIII Odyssey
Subject description: FSR Source
Reply with quote  Mark this post and the followings unread

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
Back to top
View user's profile Send private message
camelneck



Joined: Sep 27, 2008
Posts: 68
Location: KY (USA)

PostPosted: Mon May 06, 2013 7:06 pm    Post subject: Re: Painless Aftertouch Mod for MkIII Odyssey
Subject description: FSR Source
Reply with quote  Mark this post and the followings unread

Tim Servo wrote:
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


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.)
Back to top
View user's profile Send private message
AndyR1960



Joined: Feb 16, 2007
Posts: 275
Location: Manchester UK
Audio files: 5

PostPosted: Tue May 07, 2013 3:42 am    Post subject: Re: Painless Aftertouch Mod for MkIII Odyssey
Subject description: FSR Source
Reply with quote  Mark this post and the followings unread

Tim Servo wrote:
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


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 Smile

I'll get back once I've tried out the "full" interface... just waiting for the 9mm 100k pots.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [12 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
AmbiphonicDSP

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use