SHO clone level pot sweep.

[pinkphiloyd]

I built a SHO clone, and it sounds pretty damn good.  I used the 5k linear pot that's called for in the schem.  It definitely works throughout the course of it's travel, but it seems like the majority of the boost is in the last 1/4 of the pot, and definitely in the last 8th.  Is that normal?

[blooze_man]

Other schematics for it show a reverse audio pot. Sound's like that's what you need.

[Milotic]

Yes a 5k Rev. Audio is what you need.
I had a 5k linear on my first SHO and most of the gain was at the end.  but with the 5k rev. it sounded alot nicer.
If you cant find a 5k rev. audio, i think you can make one with a 10k resistor and a 10k lin. pot.

[pinkphiloyd]

Okay.  Yea, at the bottom it says a 5k reverse can be substituted.  I'll try that then.  Thanks.

[PRR]

> 5k linear pot
> the majority of the boost is in the last 1/4 of the pot, and definitely in the last 8th.

I'll assume "4K" pot (rounder numbers) and that there's effective 100 ohm limit on the boost.

For equal 2X increments of boost, the pot must be set to:

4K = 1X boost, knob at 0
2K = 2X boost, knob at 5
1K = 4X boost, knob at 7.5
400 = 8X boost, knob at 9
150 = 16X boost, knob at 10

So, yeah: the first 2X is half the dial, the last 2X is 1/10th the dial.

That's how this circuit works.

> a 5k Rev. Audio is what you need.

Right. 4K RevAud will be, at "5" center, not 2K but about 1K-400 ohms (they vary).

4K = 1X boost, knob at 0
2K = 2X boost, knob at 3
1K = 4X boost, knob at 4.5
400 = 8X boost, knob at 6
150 = 16X boost, knob at 10

Still not perfect "same boost per dial-mark", but not all cramped into the 8-10 zone.

Electrically it is all the same (the circuit can't see the knob). Just a matter of how easy it is to find your boost-setting.

> If you cant find a 5k rev. audio, i think you can make one with a 10k resistor and a 10k lin. pot.

NO. You can semi-fake a tapered 3-terminal POTENTIOMETER. You can not fake a 2-terminal RHEOSTAT this way.

[crispyduckman]

Hi. First post! I'm a noob but want to try putting together a SHO as my first DIY stompbox (so far only been modding SD-1 and DS-1 pedals).

I think I'll prefer to use the 5k linear to avoid wearing out my tubes and get more subtle adjustments on the lower end. However, is it just me or are both kinds of 5k pots really hard to come by (I'm in the UK). It seems like 250k and 500k are everywhere but I can't find a single 5k. Am I doing something wrong?

[frequencycentral]

Hi. First post! I'm a noob but want to try putting together a SHO as my first DIY stompbox (so far only been modding SD-1 and DS-1 pedals).

I think I'll prefer to use the 5k linear to avoid wearing out my tubes and get more subtle adjustments on the lower end. However, is it just me or are both kinds of 5k pots really hard to come by (I'm in the UK). It seems like 250k and 500k are everywhere but I can't find a single 5k. Am I doing something wrong?

4k7 is more common in the UK than 5k, and will work just fine. You should be able to pick up a 4k7B at Maplin (but not 4k7C). Or you can order 5kC from Banzai or Das Musikding in Germany.

[crispyduckman]

Thanks. That's brilliant - it was the last component on my list! Still not as common as I was expecting but good enough for me.

[Mark Hammer]

Use a regular log pot, wire it backwards, and just label the damn thing "Attenuate" instead of "Boost".