Sub for a 1kA pot?

[Micpoc]

I'm working on a fuzz pedal that requires a 1k audio pot for the output level control and they aren't available from Smallbear, my go-to potentiometer source. I can get a 1k linear pot, and I already have a 1k reverse log pot; which one would probably be better for the output?

Instead of that, I know that some tapers can be simulated with pot of different value and a resistor(s). What would be the best way to simulate a 1kA pot? Can the 1K linear be wired to simulate the 1k audio, or do I need to start with a larger value pot?

Thanks.

[midwayfair]

Post a schematic. No way to tell without seeing it.

[Scruffie]

1k output? That seems awfully low...

Yes if you want to alter a taper some leeway in value makes it easier, just due to standard values if anything.

You can just wire it backwards, a C backwards is an A.

You may find that a B or C is perfectly suitable, IME, B is usually better but sometimes awful, it depends what's loading it, as midway said, a schematic should help.

[Govmnt_Lacky]

A 1KC wired backwards WILL work....... BUT.....

It will be backwards. Your maximum output will be at full CCW and minimum will be at full CW 

If you are willing to live with that then GO FOR IT!!

[Micpoc]

Post a schematic. No way to tell without seeing it.

It's a modified version of the WEM Project V; don't have a schematic for it, but here's the traced original with the 1k Log volume pot:

http://1.bp.blogspot.com/-gEuevYYEfGg/T14SnFF7OyI/AAAAAAAABFU/sH3jau7ICkQ/s1600/WEM+Project+V+Fuzz+schematic+revision4+w+calculated+voltages+-small.bmp

[Micpoc]

1k output? That seems awfully low...

I agree. I've used a 1kC for the fuzz on my silicon Fuzz Face, but I don't think I've ever gone lower than 10k on an output... and even that is low.

Yes if you want to alter a taper some leeway in value makes it easier, just due to standard values if anything.

You can just wire it backwards, a C backwards is an A.

You may find that a B or C is perfectly suitable, IME, B is usually better but sometimes awful, it depends what's loading it, as midway said, a schematic should help.

I think the first thing I may try is subbing a 5kA pot, although having the backward volume with a 1kC may be appropriate! 

[midwayfair]

Use the 5ka or the linear 1k. I don't,t think the tracers made a mistake, but I don't understand how a transistor can drive a 1k load. I doubt it matters what raper pot you use since anything below fully open is probably going to have a big, sudden volume loss. Figure 500ohms from the transistor, that's half the pot. I just don't see the need, especially given the absurdly large output cap. You could reduce that by a factor of 10 and use a 10k output cap and still have every subharmonic known to man coming out.

What a strange circuit.

[Micpoc]

Use the 5ka or the linear 1k. I don't,t think the tracers made a mistake, but I don't understand how a transistor can drive a 1k load. I doubt it matters what raper pot you use since anything below fully open is probably going to have a big, sudden volume loss. Figure 500ohms from the transistor, that's half the pot. I just don't see the need, especially given the absurdly large output cap. You could reduce that by a factor of 10 and use a 10k output cap and still have every subharmonic known to man coming out.

I'm going to try a couple. It does seem odd to me that 1kA availability is low.

What a strange circuit.

It sure is. In case you haven't heard it:

[lincolnic]

Just wanted to chime in and say that that's an incomplete schematic, here's the finished version from the FSB thread:



For what it's worth, I recently built one of these on vero but ran into some serious problems...haven't begun troubleshooting yet but I'm not looking forward to it. It's a big build.

[Micpoc]

Just wanted to chime in and say that that's an incomplete schematic, here's the finished version from the FSB thread:

For what it's worth, I recently built one of these on vero but ran into some serious problems...haven't begun troubleshooting yet but I'm not looking forward to it. It's a big build.

Cool, thanks. I've had no success with anything except the smallest vero builds... can't imagine doing this one that way.

[lincolnic]

You're doing the Ghost Effects take on it? I considered that, but the cost plus shipping to the US was more than I wanted to pay. If I can't figure out this vero build, I may change my mind and just do that anyway.

[Micpoc]

You're doing the Ghost Effects take on it? I considered that, but the cost plus shipping to the US was more than I wanted to pay. If I can't figure out this vero build, I may change my mind and just do that anyway.

Yup. I didn't think it was inordinately high, and it actually got to me faster than some shipments from here in the US (e.g. California)... for me, anyway.

[lincolnic]

Oh, it wasn't insanely expensive, it was just more than I wanted to pay at the time - I chose to spend the money on parts for the vero build instead. I want to build his version eventually too.

[Micpoc]

Well, I hope you get both built and do a comparison demo.