I'm doing it wrong. (Big Muff Tone Wicker/Tone Bypass mod switching help).

[Bandwagonesque]

Hi everyone. I drew out a layout for a rams head big muff and would like to incorporate the following mods to it:

Tone Wicker/470pF bypass mod
Tone Bypass
Flat/Normal/Boosted mids switch.

been having trouble getting the first 2 mods to work and afraid its due to me getting the wiring wrong. Below are copies of my layout which is really just a copy of another one online but for my size needs. The first one is a normal layout with how I was assuming the switching would work out to lift all 3 470pF ceramic caps via a 3pdt switch. This doesn't seem to work though at all and while I was confident I was on the money, I must be wrong. Can anyone tell me what is amiss and how I would wire this up the right way?





Next is the same layout but instead of embarrassing myself, I figured id draw the layout as far as what im sure of, which is that I know the 10nF and 22K resistor as marked need to be lifted from ground. I had it wired as how I thought it would work but that doesnt seem to be working right either. Hard to explain but while its doing 'something', its not bypassing the tone pot as it works whether the switch is on or off. So I am going to assume both of my mods are incorrect and having trouble figuring out how to get the switching to work. For this tone bypass layout, if someone could be so kind as to what goes where from board to switch I'd be very much grateful. Thanks for any help and take care.

[Bandwagonesque]

this is such an embarrassing bump as I figured I would get it going myself over the last few nights. I may have the tone bypass sorted (turns out i may have a bad switch so awaiting an order as well as seeing my own error in wiring), but the tone wicker is really throwing me as for what i've been told and read online this is how it should be wired up. Could anyone tell me if its at least beyond the pale wrong so I can go about finding the solution from there? Would much rather learn than be told to be honest but switching is truly my achilles heel. Sorry for the bump ya'll and take care.

[KarenColumbo]

I would love to help you get this going since this about the meager scope of my electronic knowledge (that, and I'm a chronic tinkerer and "modder"). But I really hate to try to read stripboard - do you have a REAL schematic for this contraption there?

[Bandwagonesque]

hi karen, thanks a lot for the offer on the help and forgive me for not getting an original schem up. Here is what my layout should be based off of.




and here is the un-modified layout just in case it helps.




thanks again Karen 

[Fancy Lime]

The important question that the schematic does not answer is: what the huh is the "tone wicker mod". I have read it mentioned but have never seen a schematic or read a proper description of what it does. If we have that info, we may be able to help.

Andy

[antonis]

I'm confused a bit about what you wish to do but below is the right mode for Tone selection..
(in case of simple bypass, a 150k resistor in place of "other folter" should handle volume raise..)

[FiveseveN]

the right mode

I'm guessing in that mod the "Other Filter" is capacitively coupled, which a 150K resistor is not.
So make the splice before C3, otherwise

[Bandwagonesque]

The important question that the schematic does not answer is: what the huh is the "tone wicker mod". I have read it mentioned but have never seen a schematic or read a proper description of what it does. If we have that info, we may be able to help.

Andy

Hello. sorry for not being more specific but the tone wicker mod is a feedback capacitor lift on all 3 of the 470pF caps. I think. I was actually just trying to get it working to experiment with as I heard neat things in being rid of them.

and thank you so much antonis and and Fiveseven for your help. can't wait to try these out after work and then smack my forehead a bit. 

[Fancy Lime]

The important question that the schematic does not answer is: what the huh is the "tone wicker mod". I have read it mentioned but have never seen a schematic or read a proper description of what it does. If we have that info, we may be able to help.

Andy

Hello. sorry for not being more specific but the tone wicker mod is a feedback capacitor lift on all 3 of the 470pF caps. I think. I was actually just trying to get it working to experiment with as I heard neat things in being rid of them.

and thank you so much antonis and and Fiveseven for your help. can't wait to try these out after work and then smack my forehead a bit. 

In that case, what you posted in your first post should work. Be careful with the orientation of the switch, though. With switches with 3x3 poles I have often made the mistake of installing it 90° the wrong way. Also, switches are among the least reliable parts we use. So taking a DMM to the stitch and checking if it works correctly is probably a good idea.

Hope that helps,
Andy

[antonis]

the tone wicker mod is a feedback capacitor lift on all 3 of the 470pF caps.

There are more simple ways to make a BMπ a squealing beast.. 

[duck_arse]

do you have a circuit diagram of this squealing beast, antonis?

[antonis]

Just grasp any Big Muff pi version you like and get rid of all feedback (Miller) capacitors, Stephen..

[duck_arse]

yes, yes, but you have lost my point, antonis.

[Bandwagonesque]

Hi everyone, hope all had a good holiday and thanks again for all your input as its been helpful in seeing the errors of my ways.  Was sizing this up finally last evening based off of the revisions made by antonus and fivesevens correction and have an idea as to where I would stick the 'D' and 'B' break points on the circuit/diagram that go the DPDT switch. But I'm having a real hard time figuring out where to stick the 'A' and 'B' points. I know what bus if falls on (the one that starts on C-11 and ends on N-12) but not sure where to stick the break point there. Could someone tell me where I would make the cuts here or lay out the coordinates battleship style on my layout? I'm rather confident I know how to lift the one end up of the tone circuit but just having a hard time with the other so any help would be so appreciated.

My instincts are telling me I may need to move some components around but also have half of me saying it should be as simple as laying the cut point right on that bus, just not sure exactly where with all the components in play. Sorry if this seems obvious and if I still have yet to have it click. 

here is the layout once again to help

[Bandwagonesque]

sorry for the bump in this. im still having a bit of issue with my wiring though im on the right track it seems. im still real green and switch wiring is my achilles heel.

I managed to find the right spots on my layout to cut traces and put a wire up from the end of each new end to send to a switch. I made my cuts as seen here with 4 leads coming out of each new end to the traces. (BLUE AND GREEN for one and RED and ORANGE for the other. Problem is when I sent them to a switch and wire it per antonis' specs, it seems to shut off the entire pedal totally on one setting, instead of bypassing the tone stack so I can switch between tone circuit IN the circuit, or tone circuit OUT of circuit. Am I wiring this up wrong? below is the layout with where my leads are currently popping out from. Can someone tell me where I need to send them on the poles of a dpdt on/on switch? I really don't think it should take more than 4 wires to do this correct? Sorry if this has been beaten to death before but just looking for the most correct and definitive way to make it switchable. 

[duck_arse]

I have to say this as gently as possible, because it gets me in trouble far too much - draw the circuit diagram**. somebody soon is going to have to draw a bigmuff circuit with an added switch.

your layout part ID's don't match the snippet Antonis [the great man] posted, so I won't quote from it. but two questions - did you short across two of the switch contacts, as per antonis's drawing? when you say it "seems to shut off the entire pedal totally on one setting", is that in the "tone bypass" position?


orange to 4. yellow to 6. 1 and 2 short/linked. blue to 3. green to 5. checkmate.

[edit :] ** draw the circuit diagram. can't work switches? draw something, and we'll tell you where it's right and wrong. a good way to lern. they are the simplest of all circuit elements.

[antonis]

Just to add I'm confused s bit about DPDT switch lugs numbering and orientation..

For a vertical positioning, 2 goes to 3, 3 goes to 5, 4 goes to 2 and 5 goes to 4..

[duck_arse]

Just to add I'm confused s bit about DPDT switch lugs numbering and orientation..

For a vertical positioning, 2 goes to 3, 3 goes to 5, 4 goes to 2 and 5 goes to 4..

antonis, I was hoping to avoid confusion and argument by referring to the OP's numberings.

[duck_arse]

it has already been done, at least twice. see here [although the images aren't displaying here in preview ....]





version 3 seems to have at least one too many caps in the tone bypass setup. also note the series resistor, which will be needed to prevent the huge volume jump when switching the tone stack out. as for how to stop the cap popping, and which to leave out, I don't know.

[antonis]

The only cap which might be prone to "popping" is the 100nF one..
(the one between Tone pote wiper and output transistor Base..)

By placing a 4M7 to 10M resistor from the "open" leg (the one pointed D) to GND you'll have a permanently grounded cap without affecting transistor bias..