madbeanpedals::forum

Projects => General Questions => Topic started by: irmcdermott on July 20, 2011, 04:58:22 PM

Title: 100kC Dual Gang Pots
Post by: irmcdermott on July 20, 2011, 04:58:22 PM
Where are you guys getting them from, since Small Bear is seemingly always out of the 16mm ones? Or are you just using the 24mm ones he sells? Trying to source my Quadrovibe build, having a little trouble. Or... I'm willing to offer up my etching skills or other items in a trade if someone has one they can part with. If that's the case, PM me as to not pollute a "General Questions" thread with trade negotiations :)
Title: Re: 100kC Dual Gang Pots
Post by: madbean on July 20, 2011, 05:30:40 PM
I didn't realize SB was out.
You can use a 250kB dual and put a 330k resistor on each row of lugs to approximate 100kC (this is from the Forum Vibe).

Title: Re: 100kC Dual Gang Pots
Post by: cjkbug on July 20, 2011, 05:38:34 PM
tayda electronics has them
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 20, 2011, 06:23:21 PM
you guys are the best! thanks.

cjkbug, did you mean that tayda has the 250kB ones? I couldn't find the 100kC there.
Title: Re: 100kC Dual Gang Pots
Post by: k.rock! on July 20, 2011, 06:26:24 PM
Is using a 100kA and wired backwards an option? If it is, mammoth has them:

http://www.mammothelectronics.com/RV16A01F-10-15R1-A-p/230-100-a.htm

-Kaleb
Title: Re: 100kC Dual Gang Pots
Post by: madbean on July 20, 2011, 06:29:46 PM
If you use the 250kB, make sure you do not connect the wires between lugs 2 and 1 on each row, otherwise it won't work properly.
Title: Re: 100kC Dual Gang Pots
Post by: cjkbug on July 20, 2011, 07:04:34 PM
Quote from: irmcdermott on July 20, 2011, 06:23:21 PM
you guys are the best! thanks.

cjkbug, did you mean that tayda has the 250kB ones? I couldn't find the 100kC there.
keep looking that's where I got them.
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 20, 2011, 07:15:35 PM
Quote from: cjkbug on July 20, 2011, 07:04:34 PM
Quote from: irmcdermott on July 20, 2011, 06:23:21 PM
you guys are the best! thanks.

cjkbug, did you mean that tayda has the 250kB ones? I couldn't find the 100kC there.
keep looking that's where I got them.

ok, this is all they have for Reverse. No Dual-Gangs. Maybe they are out. thanks.

http://www.taydaelectronics.com/servlet/the-Potentiometer--fdsh--Variable-Resistors-cln-Rotary-Potentiometer-cln-Anti-dsh-Log-%28Reverse%29/Categories (http://www.taydaelectronics.com/servlet/the-Potentiometer--fdsh--Variable-Resistors-cln-Rotary-Potentiometer-cln-Anti-dsh-Log-%28Reverse%29/Categories)
Title: Re: 100kC Dual Gang Pots
Post by: bigmufffuzzwizz on July 20, 2011, 08:22:51 PM
I've never seen dual gang reverse pots at Tayda. I'd go for the 100kA and wire it backwards.
Maybe I missed them too..
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 20, 2011, 09:05:57 PM
Quote from: madbean on July 20, 2011, 05:30:40 PM
I didn't realize SB was out.
You can use a 250kB dual and put a 330k resistor on each row of lugs to approximate 100kC (this is from the Forum Vibe).



So Brian, you mean to just put that resistor across lugs 1 & 3 like usual, correct?
Title: Re: 100kC Dual Gang Pots
Post by: gtr2 on July 20, 2011, 09:27:21 PM
Wiring a 100kB backwards would not change the taper of the pot to a kC.

Josh
Title: Re: 100kC Dual Gang Pots
Post by: cjkbug on July 20, 2011, 10:53:11 PM
maybe I bought a half dozen about a month ago.
Quote from: irmcdermott on July 20, 2011, 07:15:35 PM
Quote from: cjkbug on July 20, 2011, 07:04:34 PM
Quote from: irmcdermott on July 20, 2011, 06:23:21 PM
you guys are the best! thanks.

cjkbug, did you mean that tayda has the 250kB ones? I couldn't find the 100kC there.
keep looking that's where I got them.

ok, this is all they have for Reverse. No Dual-Gangs. Maybe they are out. thanks.

http://www.taydaelectronics.com/servlet/the-Potentiometer--fdsh--Variable-Resistors-cln-Rotary-Potentiometer-cln-Anti-dsh-Log-%28Reverse%29/Categories (http://www.taydaelectronics.com/servlet/the-Potentiometer--fdsh--Variable-Resistors-cln-Rotary-Potentiometer-cln-Anti-dsh-Log-%28Reverse%29/Categories)
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 27, 2011, 03:23:59 AM
Quote from: madbean on July 20, 2011, 06:29:46 PM
If you use the 250kB, make sure you do not connect the wires between lugs 2 and 1 on each row, otherwise it won't work properly.

Maybe my brain is just fried right now. But can you explain how to go about this? What lugs are the 330k resistors going on? Also, if I don't connect 2 & 1, do I just leave lug 1 unconnected? I'm scratching my head trying to figure it out.
Title: Re: 100kC Dual Gang Pots
Post by: maysink on July 27, 2011, 05:24:09 AM
You connect the 330K resistors between lugs 1 & 3 of EACH ganged pot of a 250KB dual-ganged pot to make a "100K-ish rev. log dual ganged pot." This is according to the Forum Vibe build docs. How a linear pot becomes rev log is beyond me...

You would then wire the dual ganged pot as normal; lugs 1, 2, & 3 (x2) to wherever they are supposed to go.

When I have tied a resistor between lugs 1 & 3 in the past, I tucked it behind the lugs in shrinkwrap and soldered it into the hole for each lug. That might make no sense but here's where I stole the idea (http://www.buildyourownclone.com/board/viewtopic.php?f=9&t=6401&p=179036&hilit=shorted#p179036). Just expand the concept to lugs 1 & 3.
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 27, 2011, 01:53:45 PM
Quote from: maysink on July 27, 2011, 05:24:09 AM
You connect the 330K resistors between lugs 1 & 3 of EACH ganged pot of a 250KB dual-ganged pot to make a "100K-ish rev. log dual ganged pot." This is according to the Forum Vibe build docs. How a linear pot becomes rev log is beyond me...

You would then wire the dual ganged pot as normal; lugs 1, 2, & 3 (x2) to wherever they are supposed to go.

When I have tied a resistor between lugs 1 & 3 in the past, I tucked it behind the lugs in shrinkwrap and soldered it into the hole for each lug. That might make no sense but here's where I stole the idea (http://www.buildyourownclone.com/board/viewtopic.php?f=9&t=6401&p=179036&hilit=shorted#p179036). Just expand the concept to lugs 1 & 3.

Thanks, my question was about Brian saying not to connect lugs 2 & 3 together like the wiring diagram shows if I us the B250K with the 330k resistor. So that would mean (at least in my head) that one of the lugs wouldn't be connected to anything
Title: Re: 100kC Dual Gang Pots
Post by: maysink on July 27, 2011, 05:36:38 PM
Quote from: irmcdermott on July 27, 2011, 01:53:45 PM
Thanks, my question was about Brian saying not to connect lugs 2 & 3 together like the wiring diagram shows if I us the B250K with the 330k resistor. So that would mean (at least in my head) that one of the lugs wouldn't be connected to anything

I'm thinking you do not jump/wire lug 1 to lug 2 as doing so would essentially also jump everything to lug 3 (and each other) via the 330K resistors resulting in a fixed resistor instead of a pot. So just ignore lug 1 on each gang and wire 2 & 3 as per the build doc (I am SO assuming this is about a QuadVibe!).
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 27, 2011, 05:38:44 PM
thanks. you are correct. this is for my quadrovibe build.... waiting on a shipment from Tayda before I can finish... can't wait!
Title: Re: 100kC Dual Gang Pots
Post by: maysink on July 27, 2011, 06:08:40 PM
And happy 500th post, Ian!
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 27, 2011, 06:11:30 PM
Quote from: maysink on July 27, 2011, 06:08:40 PM
And happy 500th post, Ian!

Haha. Thanks!
Title: Re: 100kC Dual Gang Pots
Post by: Haberdasher on July 27, 2011, 11:42:31 PM
Ian- I'll be curious to see if that is the right way to wire it, and  also if you think the 330K resistors were effective so I hope you'll post again on the subject.   Who knows when those 100kc dual gangs will be back in stock.
Title: Re: 100kC Dual Gang Pots
Post by: jimmybjj on July 28, 2011, 12:14:58 AM
In case you guys haven't seen this article of pot taper by RG

http://www.geofex.com/article_folders/potsecrets/potscret.htm
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on July 29, 2011, 05:02:36 PM
Quote from: Haberdasher on July 27, 2011, 11:42:31 PM
Ian- I'll be curious to see if that is the right way to wire it, and  also if you think the 330K resistors were effective so I hope you'll post again on the subject.   Who knows when those 100kc dual gangs will be back in stock.

I breadboarded the circuit last night and with the exception of a crazy loud pop on the toggle switch I have to troubleshoot, the circuit works great.

I still don't want to box it until I've gotten my hands on a dual C100K pot. I did the B250K with the 330k resistor across lugs 1 & 3 and I'm getting about 150k resistance with the pot fully clockwise.

It still seems that the first 1/2 or more of the pot is useless, but I have nothing to compare it to. I'm still tweaking the trims as well, haven't gotten them dialed in just yet. We will see. Wiring up the pot like that definitely works fine, I just wonder if the speed control would benefit more from having the C-taper pot in there.
Title: Re: 100kC Dual Gang Pots
Post by: Jamiroking on August 02, 2011, 04:49:13 PM
I just heard back from smallbear and they said they are expecting a new shipment of  dual gang 100kC pots around august 15. After they inspect them, they'll be ready in the stock list. Then we can all build our Q vibes!
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on August 02, 2011, 05:26:52 PM
Quote from: Jamiroking on August 02, 2011, 04:49:13 PM
I just heard back from smallbear and they said they are expecting a new shipment of  dual gang 100kC pots around august 15. After they inspect them, they'll be read in the stock list. Then we can all build our Q vibes!

That is beautiful news! Thanks!
Title: Re: 100kC Dual Gang Pots
Post by: dwstanford on August 02, 2011, 06:38:48 PM
Thats good to know thanks.  Ill wait to order the rest of my supplies until then.
Title: Re: 100kC Dual Gang Pots
Post by: Jamiroking on August 04, 2011, 07:21:38 PM
Sneaky Smallbear!
There's 3 in stock now, get em fast!
http://www.smallbearelec.com/Detail.bok?no=1032 (http://www.smallbearelec.com/Detail.bok?no=1032)
Title: Re: 100kC Dual Gang Pots
Post by: Jamiroking on August 12, 2011, 10:44:00 PM
...grumble...

My smallbear order shipped 4 days ago and I just now get an email saying that it does NOT include the dual gang 100kC which was the whole reason for the order and that they are now backordered until october.....

...this sucks
Title: Re: 100kC Dual Gang Pots
Post by: sprayfe on August 13, 2011, 05:42:11 AM
Quote from: Jamiroking on August 12, 2011, 10:44:00 PM
...grumble...

My smallbear order shipped 4 days ago and I just now get an email saying that it does NOT include the dual gang 100kC which was the whole reason for the order and that they are now backordered until october.....

...this sucks
Exactly the same story. I figured I may as well not order 1 pot, dangit.
Title: Re: 100kC Dual Gang Pots
Post by: Smeero on August 15, 2011, 02:17:26 PM
I ordered a pair here and it only took about 7 days to get them to Arizona.  They aren't solder lugs but they are 16mm Alpha dual 100kC pots. ( I now have an extra too!)

http://cgi.ebay.com/2x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518825?pt=LH_DefaultDomain_0&hash=item27b487bba9 (http://cgi.ebay.com/2x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518825?pt=LH_DefaultDomain_0&hash=item27b487bba9)

Finished rocking the Quad Friday... boxing time.
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on August 15, 2011, 02:20:36 PM
Quote from: Smeero on August 15, 2011, 02:17:26 PM
I ordered a pair here and it only took about 7 days to get them to Arizona.  They aren't solder lugs but they are 16mm Alpha dual 100kC pots. ( I now have an extra too!)

http://cgi.ebay.com/2x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518825?pt=LH_DefaultDomain_0&hash=item27b487bba9 (http://cgi.ebay.com/2x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518825?pt=LH_DefaultDomain_0&hash=item27b487bba9)

Finished rocking the Quad Friday... boxing time.

Thank you for the link! Ordering a few now.
Title: Re: 100kC Dual Gang Pots
Post by: irmcdermott on August 23, 2011, 09:36:36 PM
Quote from: Smeero on August 15, 2011, 02:17:26 PM
I ordered a pair here and it only took about 7 days to get them to Arizona.  They aren't solder lugs but they are 16mm Alpha dual 100kC pots. ( I now have an extra too!)

http://cgi.ebay.com/2x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518825?pt=LH_DefaultDomain_0&hash=item27b487bba9 (http://cgi.ebay.com/2x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518825?pt=LH_DefaultDomain_0&hash=item27b487bba9)

Finished rocking the Quad Friday... boxing time.

7 days to get them to Nashville. Look great! Thanks again for the link!
Title: Re: 100kC Dual Gang Pots
Post by: gtr2 on August 26, 2011, 05:42:41 PM
It looks like BYOC parts store carries the dual gang 100kC....

http://www.buildyourownclone.com/storepots.html

Josh