B2M Pots?

[vigilante397]

So I just finished a build that required a B2M pot, and I had to scour the far ends of the globe (eBay) to find one, and I wasn't even able to find one that was PCB mount.

But I'm re-designing the aforementioned build to fit in a much smaller enclosure, so I'm looking for a 9mm B2M pot. Round shaft would be preferred, but frankly whatever I can find I wouldn't be picky. I've checked Tayda, Smallbear, Mouser, Digikey, and Mammoth, all to no avail. Anyone know where I could find one? There's absolutely no way anything bigger than a 9mm pot would fit in this build

[PMowdes]

I searched for a 9mm b2M for months last year for a PLL build, I contacted a bunch of suppliers and they all said they don't offer anything above 1M in 9mm.  If you find any let me know

[FUZZZZzzzz]

have you tried banzaimusic in Berlin

https://www.banzaimusic.com

[deadastronaut]

b2m pots, i found them on ebay.......

oops only 16mm... 

[bluebunny]

You could always trim 7mm off with your laser?

   

[Phoenix]

Nathan, does your application require a potential divider, or a variable resistor? If you only need a variable resistor, then if you can find a 2 gang 1Meg 9mm pot, the two gangs could be wired in series. I don't know any dual gang 1Meg 9mm pots off hand, but I'd hazard a guess they're more likely to exist than a 2Meg 9mm pot...

[duck_arse]

https://www.allelectronics.com/item/nltp-2m/2-meg-linear-taper-pot-6mm/1.html
https://www.allelectronics.com/item/nltp-1.5m/1.5-meg-linear-taper-pot-6mm/1.html
https://www.allelectronics.com/item/ltp-255/2.5-meg-ohm-linear-pot/1.html

guess where I've been searching lately .....

[Mark Hammer]

Just a note that, if the pics they post are accurate, the pots listed as "6mm" are actually 16mm.  Typo.

[vigilante397]

I searched for a 9mm b2M for months last year for a PLL build, I contacted a bunch of suppliers and they all said they don't offer anything above 1M in 9mm.  If you find any let me know

That's what I'm doing as well I contacted Smallbear and he said the same thing, manufacturers just don't make them.

Nathan, does your application require a potential divider, or a variable resistor?

It's acting as a variable resistor, so I could get away with that, but alas dual gang 9mm pots come in very few options, 100k being the only one I'm really seeing. I may just play with the circuit to see if I can find a good useful range of about 1M then fix resistors to make up for the rest.

Or I may just give up on the whole project, as it's a bit ridiculous. I just finished a PLL build on deadend-fx's PLL One PCB (thanks PMowdes and Dino!) and started thinking about how neat it would be to have a PLL in a 1590B. If I use 9mm pots and squish them together I can fit 5 in a row, so two rows of 5 and one row of 4. I would leave off the momentary section as I don't really care for it, and turn the Swap footswitch into a toggle, which would bring my grand total to: 14 pots, 4 SPDT toggles, 2 DPDT toggles, 2 footswitches, and 2 mini-rotary switches (I would get rid of one of the multiplier options so I could use SP8T switches for both) and it would be INSANELY tight but I think I could do it. But again, it ABSOLUTELY HAS to be 9mm pots.

So anyway, thank you all for your help, and if this ends up happening you'll of course see it on here somewhere

[bluebunny]

Just a note that, if the pics they post are accurate, the pots listed as "6mm" are actually 16mm.  Typo.

6mm is the shaft diameter.

[PMowdes]

I would be interesting to see how earthquaker have done the data corruptor, I guess they have buying power to be able to order 1000s so perhaps they got them custom made

[davent]

Could you hack a 2M trimmer to do the job, somehow fit a shaft to the screwdriver receptacle?
dave

[vigilante397]

Could you hack a 2M trimmer to do the job, somehow fit a shaft to the screwdriver receptacle?
dave

I came across a thread that mentioned doing something like that, but I'm not sure I would trust it mechanically. I'm not very gentle with my pedals

Though I was thinking about Phoenix's comment about a dual-gang run in series, and I could try running a 1M trimpot in series with it, so I can adjust it after building to get a usable sweep with a 1M pot for the control.

[Rob Strand]

So I just finished a build that required a B2M pot, and I had to scour the far ends of the globe (eBay) to find one, and I wasn't even able to find one that was PCB mount.

Why not just scale the circuit so you can use a 1MB?

[digi2t]

You could always trim 7mm off with your laser?

   

You'd end up with a B1M1 in that case. 

[Rob Strand]

You'd end up with a B1M1 in that case. 

I'm not sure if scaling down and pruning back are the same 

[anotherjim]

I'd mod it to fit some resistance between the pot and pin13 of the pll chip and use a 1M pot. I doubt it's the most predictable thing to adjust anyway. Also, the thing really ought to have some fixed minimum resistance coming out of the phase comparator pin13 and as it stands both the Response and Loop track pots can be set to zero. Tack solder a little 1M trim pot in series and find a sweet spot value for a fixed resistor to go in there.

[vigilante397]

Tack solder a little 1M trim pot in series and find a sweet spot value for a fixed resistor to go in there.

That's a good idea, as it gets me the same result but with a smaller component. I may be able to fit a trimpot permanently in the layout, but it would be nice to not have to.

[vigilante397]

Finally finished my 1590B PLL layout, I'm going to mill out a test board with these dimensions before I fab it to make sure it's going to fit. I was able to fit all 14 pots, and I'm planning on having both the Drone and Bypass footswitch, but the Swap is now an SPDT toggle. I also had to change the A and B DPDT's of the Drone section into SPDT's, which means it loses the middle selection, but there was absolutely no way to make it fit otherwise and I wanted to keep as much of the drone section in tact as possible. I also had to bring the Multiplier switch down to SP8T, which means losing one setting, but I couldn't find anything more than SP8T in that form factor. I don't have 3D models for several of the parts I used, but this gives an idea of what it will look like:

[PMowdes]

Finally finished my 1590B PLL layout, I'm going to mill out a test board with these dimensions before I fab it to make sure it's going to fit. I was able to fit all 14 pots, and I'm planning on having both the Drone and Bypass footswitch, but the Swap is now an SPDT toggle. I also had to change the A and B DPDT's of the Drone section into SPDT's, which means it loses the middle selection, but there was absolutely no way to make it fit otherwise and I wanted to keep as much of the drone section in tact as possible. I also had to bring the Multiplier switch down to SP8T, which means losing one setting, but I couldn't find anything more than SP8T in that form factor. I don't have 3D models for several of the parts I used, but this gives an idea of what it will look like:

Nice work Indeed.if I had to redesign it again i'd be inclined to strip the drone section down to two pots, I don't really see what having four adds to the functionality. 

What I really dig is the CV input used with the harmonizers toggled to the momentary switch