# DIYstompboxes.com

## DIY Stompboxes => Building your own stompbox => Topic started by: gigimarga on May 14, 2009, 05:23:16 PM

Title: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 14, 2009, 05:23:16 PM
Hello,

I am a big fan of Big Muffs and i like a lot the Triangle, the Ram Head and the Civil War models.
I am curious if i can to wire all of them in one box, using only 3 pots.
Using all my brain and all my electronical skills i found two possibilities:

1. using a (rotary) switch with 8/9 poles and 3 positions (but i have no ideea if exists this kind of switch...here i can find switches with maximum 4 poles and 3 positions!!!):

• 2 poles for the "Gain" pot (lug 1 is in all 3 schematics wired to ground using a 1K resistor)
• 3 poles for the "Tone" pot
• 1 pole for the "Volume" pot (lug 1 is wired to ground and lug 2 is wired to the output anyway)
• 1 pole for the input
• 1 pole for the LED (with 3 colors)
• 1 pole for the power (optionally...i can keep all the Big Muffs wired to the power all the time)

2. using 2 triple pots (but i have no ideea if exists triple pots!!!) and a switch with 3 poles and 3 positions:

• 1 pole for the output (which goes to the third leg of the "Volume" pot)
• 1 pole for the input
• 1 pole for the LED (with 3 colors)

Both solutions are wrong because i can't find the switch or the pots, so i hope to find (with your help) a much clever solution!

Thx a lot all!
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: frequencycentral on May 14, 2009, 06:35:58 PM
Most of the BM varients are just a few part changes here and there. Why not make a 'Big Muff Lab' with a bunch of toggle switches to select different values for the variations?
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: 80k on May 14, 2009, 10:10:34 PM
Hmm, I don't know that there is really an easier way than simply building 3 different pedals. And whereas the circuits are very similar, there are SO MANY changes in components, that if you wanted to stay true to the circuit, you'd be flipping way too many toggle switches (and would have to remember each one).

If you are willing to engage yourself into a HUGE project and actually learn a lot in the process, you could create a digitally controlled circuit where you can include every variation of the Big Muff in existence. For instance, you'd divide up the circuit into different chunks and recreate as many circuit portions as you need to encompass all the BMP versions. And then you could digitally control which signal is allowed to flow where, and you could save patches where each patch represents a series of connections. For instance, press patch 1, and you'll have a multitude of predetermined connections made representing the Ram's Head. Press Patch 2 and you get the Civil War Muff. And etc. And you could have all the signals route to the same 3 pots and same input/output jacks.

This would also give you ability to do frankenstein versions where you can save patches that mix different chunks of different circuits.

If you are a dedicated Big Muff fan, maybe this would be a worthy project, and learn a lot for future projects. This concept is identical to the 4MS Bend Matrix (http://www.4mspedals.com/bendmatrix.php), except you don't have to use banana jacks/plugs, nor have the entire interface on the actual pedal. You could for instance have a pedal that has a single stomp switch, 3 pots, input/out jacks, DC jack, and maybe 6 lighted pushbutton switches that represent 6 different muffs. You press one and it lights up. You'd just need to program the microchip ahead of time.

I know this idea is a HUGE stretch, but this imho would be the ultimate way to achieve your vision. And every Big Muff fan will be envious of your product! :)
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 14, 2009, 10:28:12 PM

Most of the BM varients are just a few part changes here and there. Why not make a 'Big Muff Lab' with a bunch of toggle switches to select different values for the variations?

Now, I am in a time of my life when i don't like to have billions of pots/switches in a box...
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 14, 2009, 10:30:54 PM
Hmm, I don't know that there is really an easier way than simply building 3 different pedals. And whereas the circuits are very similar, there are SO MANY changes in components, that if you wanted to stay true to the circuit, you'd be flipping way too many toggle switches (and would have to remember each one).

If you are willing to engage yourself into a HUGE project and actually learn a lot in the process, you could create a digitally controlled circuit where you can include every variation of the Big Muff in existence. For instance, you'd divide up the circuit into different chunks and recreate as many circuit portions as you need to encompass all the BMP versions. And then you could digitally control which signal is allowed to flow where, and you could save patches where each patch represents a series of connections. For instance, press patch 1, and you'll have a multitude of predetermined connections made representing the Ram's Head. Press Patch 2 and you get the Civil War Muff. And etc. And you could have all the signals route to the same 3 pots and same input/output jacks.

This would also give you ability to do frankenstein versions where you can save patches that mix different chunks of different circuits.

If you are a dedicated Big Muff fan, maybe this would be a worthy project, and learn a lot for future projects. This concept is identical to the 4MS Bend Matrix (http://www.4mspedals.com/bendmatrix.php), except you don't have to use banana jacks/plugs, nor have the entire interface on the actual pedal. You could for instance have a pedal that has a single stomp switch, 3 pots, input/out jacks, DC jack, and maybe 6 lighted pushbutton switches that represent 6 different muffs. You press one and it lights up. You'd just need to program the microchip ahead of time.

I know this idea is a HUGE stretch, but this imho would be the ultimate way to achieve your vision. And every Big Muff fan will be envious of your product! :)

Too complicated for my knowledges and i don't have so much for learning...maybe the last option...
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: Taylor on May 14, 2009, 11:21:47 PM
I think the easiest way to do this would be to make 3 separate circuits, then use a dp3t to just switch the input and output to the I/O of each circuit.

9p3t switch or a 3-gang pot will be super expensive (unless you can find an old salvaged 3-gang pot on ebay). I recently got a quote for 5-gang pots: \$125 each at a quantity of 20.

Edit: I was curious, and I'm always interested in really weird parts, so I found a 9P3T switch for sale:

http://www.electronicplus.com/images/products/T-223.jpg
http://www.electronicplus.com/content/ProductPage.asp?pagenum=2&lname=&maincat=sw&subcat=srt

Only \$35.
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: grolschie on May 15, 2009, 03:35:05 AM
3x circuits, 3x 3-ganged pots, and 3x 3PDT switches?
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: nelson on May 15, 2009, 03:57:37 AM
Replace the pots with LDR's in the circuit and have the three pots control the LDR's. You could also use PWM and CD4066, but that would require a bit of extra circuitry.

Then just bypass the circuits as normal with a rotary switch.

You could also use digital pots, using momentary switches to increase/decrease the resistance.

Here's an example.

http://www.electronics-lab.com/projects/misc/025/index.html

Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: Gila_Crisis on May 15, 2009, 04:08:50 AM
Most of the BM varients are just a few part changes here and there. Why not make a 'Big Muff Lab' with a bunch of toggle switches to select different values for the variations?

i did this once!!
this is my "Multi vintage big muff" with switches to go from triangle to ram's head values
(http://i37.tinypic.com/246j239.jpg)
the switches are for:
- collector resistors on Q1-2-3
- base resistors on Q1-2-3
- emittor resistors on Q1-2-3 (i added this one later)
- tone resistors
- input and output caps + caps in series with the diodes
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: MarcoMike on May 15, 2009, 05:32:21 AM
2 muffs in one box would be quite easy... wouldn't that be enough?

2xpots are cheap and available and you can mix the value just taking them apart and adding the "second one" to a different value single pot.

the rotary thing idea wouldn't be my choice, because of the resulting super wire mess... then, they are a bit too deep for any enclosure...
... but expensive?! not really!
3x3x3 @ 5.71€ (http://www.banzaieffects.com/Rotary-Switch-3-level-3x3x3-pr-20279.html)
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 18, 2009, 02:45:11 AM
Thx a lot all for yours answers!!! You're fabulous!

@Taylor: I have 3 distinct circuits, but these means 3x3=9 pots...and my dream is to have only 3 pots!
Your 9P3T switch looks wonderful...i think that will be the solution...the only problem is that is enough hard for me to buy from USA!

@nelson: LDR seems to be a very elegant solution (and easy to do for me...i can buy some LDRs and LEDs from the local stores), but how I will control the LDR to take values in the interval 0-100K? It's possible to obtain 0 ohms with a LDR? Can you give me more details?

@grolschie: too expensive...i have a new Big Muff which i don't like how it sounds and i want only to modify it...

@Gila_Crisis: too much switches...too complicated...but seems to be very versatile...

@MarcoMike: maybe i will put only 2 if i will ont find any affordable solution...the 3x3x3 isn't enough for what i want, i think...
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: nelson on May 18, 2009, 03:23:07 AM
Thx a lot all for yours answers!!! You're fabulous!

@Taylor: I have 3 distinct circuits, but these means 3x3=9 pots...and my dream is to have only 3 pots!
Your 9P3T switch looks wonderful...i think that will be the solution...the only problem is that is enough hard for me to buy from USA!

@nelson: LDR seems to be a very elegant solution (and easy to do for me...i can buy some LDRs and LEDs from the local stores), but how I will control the LDR to take values in the interval 0-100K? It's possible to obtain 0 ohms with a LDR? Can you give me more details?

@grolschie: too expensive...i have a new Big Muff which i don't like how it sounds and i want only to modify it...

@Gila_Crisis: too much switches...too complicated...but seems to be very versatile...

@MarcoMike: maybe i will put only 2 if i will ont find any affordable solution...the 3x3x3 isn't enough for what i want, i think...

It's not possible to go to 0R with an LDR, however, youvdo get LDR's that get very low. Parallel the LDR's with a resistor to get a max of 100K. In saying that, the only value that needs to critically be 100K is the Tone control. You could modify the tone control to get the same sweep with a larger pot/variable resistance. The other pots could easily be 500K, or even 1M in total resistance.

You also need to increase the value of one LDR, and reduce the value of another to get a voltage divider response as in the tone control. That's simple to do by inverting the control voltage with an inverting opamp and feeding it to the other LED/LDR.

I still think the digital pot is the most elegant solution - 6 momentary buttons controlling all 9 pots, rotary switch selecting which muff is in signal chain.

Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 18, 2009, 04:23:20 AM
It's not possible to go to 0R with an LDR, however, youvdo get LDR's that get very low. Parallel the LDR's with a resistor to get a max of 100K. In saying that, the only value that needs to critically be 100K is the Tone control. You could modify the tone control to get the same sweep with a larger pot/variable resistance. The other pots could easily be 500K, or even 1M in total resistance.

You also need to increase the value of one LDR, and reduce the value of another to get a voltage divider response as in the tone control. That's simple to do by inverting the control voltage with an inverting opamp and feeding it to the other LED/LDR.

I still think the digital pot is the most elegant solution - 6 momentary buttons controlling all 9 pots, rotary switch selecting which muff is in signal chain.

Thx a lot for your answer...i will try to use LDRs...anyway, how can i control the LDR with a pot?
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: nelson on May 18, 2009, 06:08:50 AM
:icon_eek:

Em, vary the current to the LED with the pot. You could set the pot up as a voltage divider or as a variable resistor....

Personally, I don't see the point of doing it this way, I mean, the homemade optocouplers and supporting inverting opamp prob work out at more than the cost of the pots. It seems rather pointless.

I would go with say 2 or 3 rotary switches to switch diff values in and out of the circuit.

That way you only have to populate one board, can use the 3 existing pots and you don't have to mess around with any voltage controlled resistors of any sort.

Kind of like gila crisis' pedal, but with rotaries instead of toggles.

Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: Vitrolin on May 18, 2009, 08:36:56 AM
http://www.diystompboxes.com/smfforum/index.php?topic=75732.0

Maybe this would be useful, check out Jkowalski's 27P4T, i know there are XXP3T dataswitch boxes around, just be aware at the fleamarkets, and they come in pretty good enclosures too

...and they are cheap...important factor
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 18, 2009, 09:27:48 AM
:icon_eek:

Em, vary the current to the LED with the pot. You could set the pot up as a voltage divider or as a variable resistor....

Thx a lot and sorry for my English...my question could be "It's enough a pot to vary the LED or i need a few components around?"
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 18, 2009, 09:30:05 AM
http://www.diystompboxes.com/smfforum/index.php?topic=75732.0

Maybe this would be useful, check out Jkowalski's 27P4T, i know there are XXP3T dataswitch boxes around, just be aware at the fleamarkets, and they come in pretty good enclosures too

...and they are cheap...important factor

Thx a lot...i try tou found a switch like that in a some old radios or something like that :)
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: Vitrolin on May 18, 2009, 09:35:05 AM
http://www.diystompboxes.com/smfforum/index.php?topic=75732.0

Maybe this would be useful, check out Jkowalski's 27P4T, i know there are XXP3T dataswitch boxes around, just be aware at the fleamarkets, and they come in pretty good enclosures too

...and they are cheap...important factor

Thx a lot...i try tou found a switch like that in a some old radios or something like that :)

they aren't from radios, the dataswitchboxes are for printer switchin (pre-USB connection) between dot printer or ink printer
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: Russjp1985 on May 18, 2009, 12:48:41 PM
You could break the Muffs into 3 logical sections and then put a rotary switch on each one, allowing you to make combinations of each section.

For example you have:
The first 3 gain stages on a 4-pole rotary: 1 for input, 2 for the sustain pot, 1 output
The tone stack on a 3-pole rotary: 1 input, 2 for the tone pot (the third lug of the tone pot goes to right to the input of the 4
The last gain stage on a 2 pole rotary: 1 input, 1 to the volume pot (which serves as output).

Rather than having tons of different toggles and switches everywhere, you have a more simple and logical pedal where there is 1 rotary for each knob, which controls that respective portion of the circuit (the Sustain knob's rotary chooses the clipping stages, the Tone knob's rotary chooses the tone stack, the Volume knob's rotary picks the recovery stage).  You could use this set up to create tons of different Muff tones - you could do Ram's Head clipping stages with a Triangle tone stack and a Civil War recovery stage, etc etc.  Yet at the same time you'd easily be able to get to "stock" settings for 3 different Muffs of your choosing.

If you use 12-pole rotaries, you could potentially have up to 72 different Muffs (3 clipping stages x 4 tone stacks x 6 recovery stages) out of a 6 knob pedal.

Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: petemoore on May 18, 2009, 03:58:24 PM
I can see how this'd be different than just putting variable gain and frequency or clipping threshold values on a switch.
Just seems like it might be the long way around both sides of the barn when there's a path right down the middle.
It really helps to build 2 and ''race them'' to find out what it is you really like in one, simply adding or cutting a modest boost with some frequency variation is worth considering, tweeking from the angle of gain/frequency/when/where...
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: Ben N on May 18, 2009, 04:20:43 PM
Do the differences in the input stage actually matter sonically (other than the input/coupling caps)? I mean, it's a simple booster, and whatever distortions are taking place in that stage are getting swamped downstream. If not, why not share the input stage and sustain pot, and do your switching after that. Same question for the recovery. Seems to me that the sonically significant differences are mainly in the two clipping stages (transistors, source resistors, diodes & coupling caps) and the tone stack, so that's where you would have your redundant circuits and switching. Maybe put them on daughter boards that plug into end-connectors so you can fool around with it.
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: ninjaaron on May 19, 2009, 01:36:55 AM
I can't believe nobody has suggested relays yet. ???

You could wire up a cheap(ish) SP3T switch to turn power on or off as many relays as you like.

This seems like the obvious way to go, from my perspective.
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 19, 2009, 11:09:03 AM
Do the differences in the input stage actually matter sonically (other than the input/coupling caps)? I mean, it's a simple booster, and whatever distortions are taking place in that stage are getting swamped downstream. If not, why not share the input stage and sustain pot, and do your switching after that. Same question for the recovery. Seems to me that the sonically significant differences are mainly in the two clipping stages (transistors, source resistors, diodes & coupling caps) and the tone stack, so that's where you would have your redundant circuits and switching. Maybe put them on daughter boards that plug into end-connectors so you can fool around with it.

I thought about this, but i found too much differences between the stages, and, let's say, i want the original sound as much as possible...thx a lot anyway for your suggestion!
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 19, 2009, 11:13:05 AM
I can't believe nobody has suggested relays yet. ???

You could wire up a cheap(ish) SP3T switch to turn power on or off as many relays as you like.

This seems like the obvious way to go, from my perspective.

Thx for your answer too...i thought about relays, but i think i don't have enough space in the box.
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: ninjaaron on May 19, 2009, 04:28:30 PM
Mouser has 'Omron GK6 Series: Ultra Small 1A DPDT Low Signal relays' You can get them PCB mount, and they are like 10x6.5x5.2mm

Really, mouser has a lot of tiny relays. I'm kinda in awe at the price some people pay for a single switch that does nothing more than what an SP switch and a couple cheap relays would.

Frantone was hip to this, and incorperated relay based switching into several of her designs, I belive.

Relays will probably eat batteries pretty fast, but who's using batteries these days anyway?
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: Ben N on May 19, 2009, 10:01:29 PM
Some of the new Way Huge/Dunlop pedals have relay switching.
Title: Re: It's possible to wire 3 Big Muffs in a single box using only 3 pots?
Post by: gigimarga on May 20, 2009, 01:21:39 AM
Relays will probably eat batteries pretty fast, but who's using batteries these days anyway?

MEEE...when i'm playing at home i am enough lazy to use batteries... ::)