So, I have a linear taper pot for my tone pot right now in my Jem-inspired build. After stringing it up and doing some tests, Im unhappy with how the tone only really changes in the last 10%. I had read that this was why they use audio taper on volume, but that linear is better for tone.

Since I am going to be buying and rewiring a new pot anyways, I had the idea of using a push pull pot, where the push pull would activate or deactivate a black ice style passive distortion.

This is the wiring I have currently, but the killswitch part is integrated into a shadow killpot. Could you guys help me with how this passive distortion would work in the circuit? can it be connected to a push pull pot off the tone knob?

thanks for your help. also any experience you have with passive distortion, share your experiences. I know it cant replace many types of tone, but I like to have lots of gadgets.

The black ice distortion is just a few diodes strapped together to make a soft clipping distortion. Don't buy a black ice, the parts to make it are much cheaper.

http://www.seymourduncan.com/tonefie...hout-a-battery

so it is important to understand that distortion comes from "clipping" the signal. By that i mean that you cut out the vally and peak of the sine wave being produced. So really you want a passive clipping curcuit to give you distortion.

the black ice cap is basically 2 diodes wired together. A diode is a one way gate that will let AC like that from your pickup pass but not return back. They use diodes to turn AC in to DC (rectify). They are also used to create clipping.

check here for an experiment done using diodes to get passive distortion.

http://www.tdpri.com/forum/archive/i.../t-301449.html
http://www.unofficialwarmoth.com/index.php?topic=610.0

In summery you should try to find a lower gate point on a diode something like 500mv to 750mv. Also playing around with the material like germanium or sillicone. I would also wire the diode to a push/pull pot so it wasn't active all the time.

as in the tread above the lower the gate vaule the more clipping there will be and also some signal loss so you may need to use one or two very small vaule caps (same thing as a high pass cap on the JS1000s) to help some of your high end pass back in to the signal loop.

i hope that helps you out

Yeah, I only said black ice STYLE. I was planning on getting diodes in stead. The question is how to wire it into a push pull pot.

I think this is because I dont have a very good understanding of how push pull pots really function.
I would like to have the tone knob still function, but use the push pull as a switch to integrate the distortion. Can the pot work like that?
Would the knob still control tone? or would it control distortion? or would it not work?

Thank you for the thoughtful replies.

It'll do tone or overdrive. Be aware that the black ice type od is extremely subtle though, you might not find it that useful.

I understand it wont be extreme, but I dont see any downsides to added the passive distortion, since I dont have to use it.
Only possible negative I see is maybe introducing noise? but i dont think that would even matter unless i have it on.

I wouldnt drill a hole for it, but if I can add a push pull pot, Im all for it.

http://www.unofficialwarmoth.com/index.php?topic=610.0

check there for info on how to wire the diodes up.


If you need an example i will try and draw one out for you.

Thanks for the link, but I have already read that. He is doing something different from me. He is hooking the cap and diodes both to the pot, making things more complicated since the tone and distortion then interact.

I am looking to mix a standard tone knob, with the two way switch distortion I linked above. If someone could diagram how to connect the diodes to the dpdt switch on the push pull, that would explain it. I have heard you can wire a dpdt to do a function just like a lesser switch, but I don't know which posts to utilize.

http://www.stewmac.com/freeinfo/i-6065/i-blackice.pdf (for reference)


So take the hot lead from your volume pot (the outside non-grounded terminal) and run it to one of the outside lugs of the DPTP switch

Solder both of the middle lugs of the DPDT switch together.

On the opposite side that you connected the volume's solder a wire that will go to the diodes. So it would look something like this.

blank...................0...0---- soldered to the grounded diodes
soldered together--0--0----and soldered to the outside non-grounded lug of the tone pot
volume pot lead----0...0.....blank

that should give the ability to to use your tone pot like normal then flip the switch to engage the diodes and use your tone pot to help control the diode.

That is very helpful, and would seems to work (from what I understand). But wouldnt it be the case that when the switch is up, both the diode and capacitor will be controlled by the pot? In the warmoth thread you linkd, it seemed that that was creating some problems.

Could I do this?

blank...................0...0---- soldered to the grounded diodes
blank...................0...0----soldered to the signal from volume, and then to the 1/4 in jack.
blank...................0...0.....blank

That would just be an on off switch right?

Also, I think there may be complication/mistake in your diagram. When the pot is pulled out, the signal isnt in the circuit anymore.

so to correct this, I think it would need to be like this.
volume pot lead....0...0---- soldered to the grounded diodes
soldered together--0--0----and soldered to the outside non-grounded lug of the tone pot
volume pot lead----0...0.....blank

This would have the effect of a standard tone control when in, and the tone control in parallel with the diode circuit when out.

EDIT: I think this is the relevant part of the black ICe instructions. I think this may be better than either of our ideas, becauce it makes it so that the capacitor and diode circuits do not interact, and both can be controlled by the pot.

i dont know because i can't see the picture you linked to. It is my browser.

anyways you have a couple of options and can play around with which one works out best for you.

As far as what i suggested, that should let your tone pot act like a normal tone pot and when you flip the switch it will engage the diodes. I said a in previous post you may consider adding a small vaule cap across the the legs of the diodes because they will kill some of your high end. The extra cap will help with that treble bleed off.

I ---------{/...}--------I
I ---------{.../}--------I
\___________________/
U (.001 uf cap)

If you do decide to go for it keep us updated on what you find. I have thought about dong this before and never got back around to it.

The picture is just part of the stewmac link you posted, the push pull pot diagram. I am going to try wiring it up tonight.
When in, it's a tone pot, when out, the tone control changes to distortion control, and the cap is replaced by the diodes in the circuit.

gottcha, i went back to the PDF. Yep that may work out a little better for you.

I will post pics tonight. Hesitant to do audio clips yet since the guitar isn't properly setup, but when I get it finished, I will post a video showing it off. Got a proline push pull 500k pot yesterday. Today I'm picking up diodes and wiring it all in.