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owel

    Nashville, USA
Pots with Center Tap
« on: April 07, 2008, 02:54:25 PM »
I can't seem to find any kind of pots with center tap on Digikey or Mouser.

Are these kind of pots "obsolete" nowadays?


Svart

    Atlanta GA USA
Pots with Center Tap
« Reply #1 on: April 07, 2008, 04:53:30 PM »
yup.

Good luck.

The last place that would even consider making them for you was OMEG and now they don't do it anymore.
Welcome to the GroupDIY leper colony! when something falls off, we just replace it with a tube!
occupation: General Electron Mayhem

Alesis X2 information repository:
http://www.theopiumdenproductions.

dale116dot7

    Calgary, Alberta, Canada
Pots with Center Tap
« Reply #2 on: April 07, 2008, 09:30:07 PM »
I tried to find them for my Effectrons. No luck. I'm replacing them with a normal pot, a PIC 12Fsomethingorother microcontroller, and an SPI pot.

Gold

    Brooklyn
Pots with Center Tap
« Reply #3 on: April 08, 2008, 01:12:54 AM »
There are some coming as part of Igor's Sontec kit.

5 50k CTPOT
2207 RD1601-20F4-30R
ALPHASTAT 63250-01610/B50K 50K LIN CENTERTAPCENTERDETENT

Must be a significant minimum order.

CJ

    California
Pots with Center Tap
« Reply #4 on: April 08, 2008, 01:20:27 AM »
They are still available.

But maybe a special order setup fee, this might be a good black market item group buy, Chlorostat still makes a tapped pot.
The 670 pots, sheesh!

Weord ground tabs, And a center tap, all on the same pot!

So there are like more terminals than Pete Segars brain .
If I can't fix it, I can fix it so nobody else can!
Frank's- www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar- http://tdsl.duncanamps.com/schematics.php

Stagefright13

    Hatboro, Pennsylvania
Pots with Center Tap
« Reply #5 on: April 08, 2008, 01:31:57 AM »
Wow another Effectron fan :)
Amateur experimenter

dale116dot7

    Calgary, Alberta, Canada
Pots with Center Tap
« Reply #6 on: April 08, 2008, 09:32:16 AM »
I have three Deltalabs boxes of various kinds. For the centre-tapped pot on the VCO/delay mult control, I am going to use a MCP42010 dual 10k pot. A top to +5V, A bottom to ground, A wiper to pot B top, B bottom to LFO output, and B wiper to original pot wiper. I've built it but haven't written the software yet. That's a project for this coming weekend. I've been writing software for a multitap delay box I've been working on... too many projects on the go.

I haven't quite worked out the audio ones because usually you can just put in a non-centre-tapped pot, and just a 2.2k resistor from the centre tap to the wiper and it works ok. It just requires careful adjustment for the 'no feedback' position. I am looking at the AD5290 digital pot because it'll do +/- 15V, I think I might do that for the audio ones.

I looked at CT pots but the minimums were too high, as CJ and Gold both pointed out. A groupbuy might work, but my solution is pretty simple and you can get the parts from Digikey. You can even DIY a simple programmer. I should post my code somewhere once I'm finished writing it.

Not only do I fix up and use old Deltalabs boxes, but I've been on an Eventide fixer-upper kick. I got and fixed a broken H949 and now I'm waiting for some RAM for a H910. I'm finding that bringing old audio gear back from the dead is more fun than building mic capsules (at least after mic capsule #250). I'd like to fix the automation computer on my Soundcraft board as well...

-Dale

Svart

    Atlanta GA USA
Pots with Center Tap
« Reply #7 on: April 08, 2008, 09:59:53 AM »
I experimented with making a centertap which worked but I couldn't guarantee it's reliability.

I purchased some cheap alpha pots and opened them up to reveal the wafer.  I drilled a small hole through the wafer just outside the track and brought a small wired through.  I used conductive epoxy/paint to glue the wire's conductor to the edge of the wafer.  it works but you have to be very careful, the carbon/plastic track doesn't give the glue a really good bond.  the glue will come off easily.
Welcome to the GroupDIY leper colony! when something falls off, we just replace it with a tube!
occupation: General Electron Mayhem

Alesis X2 information repository:
http://www.theopiumdenproductions.

Stagefright13

    Hatboro, Pennsylvania
Pots with Center Tap
« Reply #8 on: April 08, 2008, 06:43:38 PM »
That's cool Dale. I have been using my 2 Effectrons since 1982 when I bought them! Nothing sounds like them. They are fun. Especially when I patch one in and noone has any idea what it is or how I got that crazy sound.
  :green:

I did have to repair one tho about 15 years ago. One of the op amps took a dump. TL074? But they are all socketed. The good old days...

No LCD or menus it's all about the knob twisting. Gotta love it!

BTW one of mine is missing 1 cap that goes on the knob. Any Idea where to get one?
Amateur experimenter

dale116dot7

    Calgary, Alberta, Canada
Pots with Center Tap
« Reply #9 on: April 09, 2008, 10:05:02 AM »
I usually replace them with whatever I can get from Mouser or Newark or Digikey.


 

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