Silicon Tonebender / James Tonestack Troubleshoot

[Hexjibber]

Hey all,

Just wanted to ask for some assistance troubleshooting a new build/layout I've done in Eagle. It's a silicon Tonebender / DH Hot Silicon (etc etc) that I swapped the standard tone stack out for a James one to have a bit more flexibility in controlling the tone. The good news is it fires up and works but the tone controls are way off, namely;

1) The Treble pot works in reverse and the range of the pot is all at one end as well as it being far too tinny and harsh for 75% of the travel. From looking at my schematic I think I've got the pot the wrong way round so that at least solves one problem but as for the second, everything I've read says to use Log pots in the James tone stack but my problem would seem to insinuate that I should have used Linear, would anyone agree?

2) The bass pot works as intended just about, it's effect isn't all that noticeable to be honest as to me it only sounds good when fully clockwise, going back the other way just yields hollow emptiness! I've noticed that there is a significant increase in level/gain when the pot is turned fully clockwise, is this normal for a James tone stack or I have I done something wrong?

3) I changed the fat switch that swaps between input caps on the original for a pot with the same values as the Blackout Musket 'Focus' pot that does the same job but the effect isn't anywhere near as noticeable, what could be the reason for this?

Hoping you guys might be able to help, this is the first time I've tried to monkey around with a circuit and the result has left me a bit deflated!  I'm going to remove all the relevant parts and stick sockets in and see what does what but was wondering if someone would be able to shed a bit of light on where I've gone wrong!

Here's a link to the schematic;

https://dl.dropboxusercontent.com/u/42206482/Talisman%20v1.0.pdf

Cheers!
Graham

[deadastronaut]

Hi graham, try swapping c7 for a 470n....

[Hexjibber]

Hi graham, try swapping c7 for a 470n....

Hi Rob,

Cheers for the reply mate, I'll give that a go definitely. To my limited understanding that would make the sweep of the bass pot go from 470n fully anti clockwise to 10n fully clockwise so I would have more bass at the beginning of the travel? Or is it not as simple as that? Will that then affect what's going on with the treble control as well? Would like to try and understand it if I can!

Cheers dude,
Graham

[deadastronaut]

I thought you was using a log pot backwards......I need more coffee...

[Hexjibber]

I thought you was using a log pot backwards......I need more coffee...

Haha, I've got log pots on both Bass and Treble and the Treble one is backwards due to an error in my schematic as far as I can see. The range of the treble pot is also all squished up at one end so perhaps I should have used linear?

C7 is pin 3 of the Bass pot, I was going to try 1n instead of the current 470p as that value would seem to be cutting too much bass. This pot is the right way round, it just doesn't really seem to do much apart from increase gain when fully clockwise. As a bass pot though it only sounds good in one position, i.e. fully on, so it's pretty much useless!

I've got some different values for the James tone stack that I'm going to try and just see what they do so I can figure out how it works!

[deadastronaut]

they should both be log...note the lug numbers (3 at the bottom)...

check this out man. .

http://amps.zugster.net/articles/tone-stacks

[Hexjibber]

they should both be log...note the lug numbers (3 at the bottom)...

check this out man. .

http://amps.zugster.net/articles/tone-stacks

Cool cheers Rob!