Anyone try a 50k Log for Rat's Filter Control?

[80k]

I've been playing around with the filter control by changing the resistor and cap to ground immediately after the filter pot. Changing the cap from .0033uF to .0047uF seemed to help get rid of the upper range of the filter, which is nice. But then the lowest range becomes useless to me. I'm thinking a .0047uF cap with a 50k pot might end up working out well, as it narrows the filter range to the most useful areas (approximately 658 hz - 23 khz), which seems like a pretty good range to me. However, not having a 50k log pot handy, I was wondering if anyone has tried this? It seems to cover the right range, but is the taper such that it will "feel" right across the entire range?

Has anyone else discovered any better tweaks for the filter control?

[liquids]

Can't speak for this as a RAT devotee, other than spending an evening with one after years of hearing raves about it for years.  But I liked it.  That being said, the filter control is something that can be tweaked.

To me, my ears prefer multiple smaller caps doing the filtering to control high end, over one 'big' cap filtering things, to start.  I think 100K in there is pretty unnecessary if you're looking for a nicer range, so that is good thinking; the taper is also worth considering and experimenting with..why not?     The easiest solution is make the 'set' resistor between the pot and the cap to ground larger...the schematic I'm looking at say 1.5k-- try 4.7K, 10K, etc and see what you think for starters.  You can also end up setting on other values 'in between' those common values.  This would be like tuning the filter control to a darker setting to start, but will also make the 'darkest' setting even darker.  So it would be sensible to have a smaller pot value, as you mentioned, to compensate and keep the whole range usable.

Likewise, if you find the brighter side of the filter control unusable, and would like the option of a 'smoother' sound,  than also considering get a 'voicing' cap or two in there. 

By voicing cap, I mean, after the diodes, but before the tone control R-C (I would think this is the best place, but others may have clearer logic than I), you can put another 10K resistor (for example), and then likewise put a .0022uF cap to ground.  This would be a subtle high end roll off that is the time,' so to speak.  Then, start by running the filter pot at the brightest setting.  Is it too dark, or is it a better starting point than before?

Tinker with the value--try .001uF if you want it brighter, etc. Tinker with two of these kind of stages, like the BSIAB has, for example.  Maybe two small caps, maybe one big and one small. 

You'll definitely get different tones.  Even if you try duplicating a 'stock' sound with a 'darker' tone knob setting, and compare that to the closest you can get to the same amount of high end, but with one or two voicing caps in there while running the tone knob 'brighter,'  you'll hear a difference.  Experiment. 

You can then decide to put one or a pair of these 'voicing' caps on DPDT switches, with the option to go between 'stock' with no cap and one or two other 'voicings.'  In the end, you might still end up modifying your tone control value and or the cap, in conjunction with the voicing caps, as you may not need it to be as drastic...lots of options to play with 

Being really sensitive to unnecessarily bright AND muddy high end, it was always a frustration that the tone knob settings on the gain pedals I bought were always a compromise--there was rarely if ever a spot that felt like it was both smooth and clear, or bright yet not harsh.  Modding and building pedals with multiple forms of filtering and voicings as per above has really helped me get the tones I'm trying to get -- and it really helps when I'm playing through a different amp than usual, which might need a different voicing.

Good luck. 

[80k]

thanks very much for the response! I wish I still had it breadboarded... i populated my stripboard a few days ago. But it sounds like it's worth revisiting the breadboard and playing around with it a bit more... and then modify my board after it's finalized.