# The Pot dilemma



## Diynot (Jun 24, 2022)

Ok, so started building a LGSM for a coworker and after discussions of mods decided the VFE Ice Scream (sherbet edition) would better. I ordered up the board and parts that weren’t included in the LGSM BOM not paying attention to the fact that the LGSM uses a B100k vol and the IS used an A100k. So now I am left with a need for an A100k with no desire to order anything more and the choice of either an A500k or the B100k. Schematics are, of course, very similar and aside from the “hearing more even change with logarithmic” should I chuck in the B100k or the a500k?


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## Robert (Jun 24, 2022)

Click-bait title, reported!   

I've built many a TS with B100K, the Ice Scream circuit should behave no differently.


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## jimilee (Jun 24, 2022)

That is not what I thought the topic was about.


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## Diynot (Jun 24, 2022)

Robert said:


> Click-bait title, reported!
> 
> I've built many a TS with B100K, the Ice Scream circuit should behave no differently.





jimilee said:


> That is not what I thought the topic was about.


Sorry for the bait and switch guys🤣. Thanks for the affirmation on POTENTIOMETER choice though.


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## spi (Jun 24, 2022)

I've regretted every time I didn't use a log pot on a volume.

But I'm not sure what the switch to 500K would do to the control, so I'd probably stick to the B100K and regret it.


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## Mentaltossflycoon (Jun 24, 2022)




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## Diynot (Jun 24, 2022)

spi said:


> I've regretted every time I didn't use a log pot on a volume.
> 
> But I'm not sure what the switch to 500K would do to the control, so I'd probably stick to the B100K and regret it.


Yea, I feel like it’s either going to be the B taper with “no change until the last 25%” or the A500k with “all the change in the first 25%”. Meh. Not going to sweat too much ab it


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## fig (Jun 24, 2022)

bah!


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## Diynot (Jun 24, 2022)

fig said:


> bah!


Humbug?


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## fig (Jun 24, 2022)

Diynot said:


> Humbug?


Pardon, wrong dilemma. I must have taken a wrong turn at Albuquerque


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## Diynot (Jun 24, 2022)

fig said:


> Pardon, wrong dilemma. I must have taken a wrong turn at Albuquerque


Dear god, my kids have been playing Weird Al’s “Albuquerque” almost non stop for the past month


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## Bio77 (Jun 24, 2022)

I can't tell from the schematic, if leg 1 or 3 goes to ground (you can use the continuity tester to determine for yourself).  Anyway, if you solder a 20k resistor across the ground leg and leg 2 of the B100k pot it will be approximately equivalent to an audio taper. 

http://www.geofex.com/Article_Folders/potsecrets/potscret.htm


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## Diynot (Jun 24, 2022)

Bio77 said:


> I can't tell from the schematic, if leg 1 or 3 goes to ground (you can use the continuity tester to determine for yourself).  Anyway, if you solder a 20k resistor across the ground leg and leg 2 of the B100k pot it will be approximately equivalent to an audio taper.
> 
> http://www.geofex.com/Article_Folders/potsecrets/potscret.htm


Oh nice! Thanks for the heads up!


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## Bricksnbeatles (Jun 24, 2022)

Diynot said:


> Dear god, my kids have been playing Weird Al’s “Albuquerque” almost non stop for the past month


AAAAAAAAAAAAALLLLLLLLLBUQUERQUEEEEEEEEEEE


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## Diynot (Jun 24, 2022)

Bricksnbeatles said:


> AAAAAAAAAAAAALLLLLLLLLBUQUERQUEEEEEEEEEEE


“All that to say I HATE SAUERKRAUT!”


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## Bricksnbeatles (Jun 24, 2022)

Diynot said:


> “All that to say I HATE SAUERKRAUT!”


Sweetie pumpkin, do ya wanna join the Columbia Record Club?


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## Diynot (Jun 24, 2022)

Bricksnbeatles said:


> Sweetie pumpkin, do ya wanna join the Columbia Record Club?


Actually have tickets for the fam to see him in August. Queue another 3 months of Weird Al’s greatest hits courtesy of Alexa.


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## Bricksnbeatles (Jun 24, 2022)

Diynot said:


> Actually have tickets for the fam to see him in August. Queue another 3 months of Weird Al’s greatest hits courtesy of Alexa.


Saw him the day before my 23rd. My sister surprised  me with the tix bc she knew how badly I wanted to see it. Incredible show, and just by chance he did Girl U Want by Devo for the encore, and I was going to Devo the following week!


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## Diynot (Jun 24, 2022)

Bricksnbeatles said:


> Saw him the day before my 23rd. My sister surprised  me with the tix bc she knew how badly I wanted to see it. Incredible show, and just by chance he did Girl U Want by Devo for the encore, and I was going to Devo the following week!


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## swyse (Jun 25, 2022)

I thought this might be interesting and as I already had a spice model of a tube screamer that I play with I decided to plot the differences between the options. Keep in mind this is a TS808 with the gain and tone in the middle of their sweep and then the level control turned from 0%-25%-50%-75% and 100% of the rotation.


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## fig (Jun 25, 2022)

Diynot said:


>


My daughter knows the fella who did the panorama video for _Sweet Talk._


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## Diynot (Jun 25, 2022)

swyse said:


> I thought this might be interesting and as I already had a spice model of a tube screamer that I play with I decided to plot the differences between the options. Keep in mind this is a TS808 with the gain and tone in the middle of their sweep and then the level control turned from 0%-25%-50%-75% and 100% of the rotation.
> 
> View attachment 27777
> View attachment 27778
> View attachment 27776


Thanks for the visual. I ended up rolling with the b100k w/o modification and it seems to be just fine.


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## Feral Feline (Jun 26, 2022)

I don't know how to interpret swyse's scope's findings.

I see the colour bands bunch up differently between the A and B tapers, but the A100k and A500k are nearly identical in terms of spacing between coloured lines, at 10Hz — -10dB, -20dB, -30dB and -40dB.


So I guess if I had to sub out A100k for either A500k or B100k I'd choose the A500k.


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## Chuck D. Bones (Jun 27, 2022)

I'd use the pot in the BOM.


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