Friday 2 August 2013

BMP Tonestack w/ LPB1

I've noticed a recurring request on how to add tone control to layout x (where x = any layout without tone control). So i thought that i'd draw up a simple addon board for simple Big Muff Pi tone control, so that anyone can take it after any board's output. But as many of the designs (older ones in particular), have quite low output, adding BMP tonestack would do a number on the maximum level. Probably even render some moderate/low output circuits unusable. So i just added your average LPB1 booster after the tone control to act as make up gain stage. You could easily swap the trimmer for "master volume" control if you wanted to - which could be a sligth overkill in many situations.

So. Take your fuzz/od, take the output from there to this circuit's input and use the output from this as your new output. Simple but effective tone control for any design.

Needless to say, this may not be too great project by itself with missing input cap and some other small details that really want a circuit before it.


55 comments:

  1. Miro. I've been looking at this for awhile, cause I've been thinking of adding this to a fuzzface to allow some tone shaping, is there an easy way to incorporate this into a preexisting board or is it just easier to have a daughter board? Also, I've read is that it should be placed before the output cap to help avoid a lot of the tone suck issues, and if you change some of the values you can avoid the loss of mids that the BM has, is that true?

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    1. Adding it to existing layout - no. That would mean complete redraw of the original. Or. You could wire the tone stack to a pot like Beavis suggests: http://www.beavisaudio.com/techpages/BigMuffToneControl/
      Like stated in the post and the article, the loss of level will be an issue.

      Placing it before the output cap would be needed when using the tone control only. The LPB after the control here takes care of that.

      BMP tone stack is well documented and it can be tweaked to suit your needs by altering both HP and LP filters. BMP tone stack is featured in Duncan's tone stack calculator, so you should be able to tweak it accurately to your preferences.
      http://www.duncanamps.com/tsc/
      +m

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    2. don't forget to make the add on pnp... flip the power rails and use a pnp you'll be fine

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  2. This is a good idea. I am sure I can find a hundred places to put this thing. Thanks.

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  3. Nice one Miro! I've been using the passive version of this for a while and it can really affect the output level on certain effects. looking forward to trying this one out. Thanks

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  4. It's the same? : http://experimentalistsanonymous.com/diy/Schematics/Distortion%20Boost%20and%20Overdrive/Simple%20Mid%20Booster.gif

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  5. Thanks a lot, you guys rock! :)

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  6. Could this be adapted to have treble and bass controls rather than the single tone, or would that require a whole new circuit?

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    1. make the 39k resistor a 50k pot, and that will work as a treble cut. make the 22k resistor to ground a 50-100k pot and that will let you cut and boost the midrange. the original pot will still pan around the circuit.
      or look at the colorsound overdriver and compare it's tone stack to the big muffs for some clues how to do it. you'll see they are pretty similar. the same resistor in that cct going to ground can be swapped out for a pot to make a midrange control there as well.

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  7. Lovely :) I am quite interested in different tonestacks, and i wish that you would make a similar solution for the typical 'Marshall/Fender/Vox'-tone stack, like the one seen here - http://amps.zugster.net/articles/tone-stacks

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  8. This looks handy, can the 390R be replaced with anything else? I think I have some 180R

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  9. Hi, I saw in many schematics that the output cable is connected to the middle lug of the trimmer and the 100nF is conected to the left or right lug, do this make any difference in comparison with this veroboard?

    Someone can say if this vero is verified?

    Cheers.

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  10. This is really cool, I'm wondering the same thing as @pearl blues, can you post a bass, mid, treble or maybe a bass treble tone stack that can be stuck into any design?

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  11. This is really cool, I'm wondering the same thing as @pearl blues, can you post a bass, mid, treble or maybe a bass treble tone stack that can be stuck into any design?

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  12. Installed this board at the output my GuitarPCB Stage 357 and it works like a charm. Consider it VERIFIED. I will only need to adjust the tone stack to my liking. Thanks Mirosol!

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    1. Cheers Leewar! I'll tag it right away.
      +m

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  13. Awesome, I have used this a few times. Works like a charm. Next time won't have to wrestle with the perf :)

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  14. What an awesome experience this one has been! I learned about the LPB1 and the tonestack calculator in one project!

    I downloaded the tonestack calculator. Played around with it, and decided I liked the simplicity and versatility of the James circuit. So I took Miros layout and substituted in the James on the left side. Basically, take the output from the tonestack calculator into the 100nF cap on the lower right of Miros layout. (and disregard the 1M resistor shown in the tonestack to ground)

    So now I will have a Bass, Treble, Master Volume. Which is cool, because If I don't like the Mids, I just lower the Highs and Lows and just increase the Master Volume a little (although I bet I'll get some minor distortion). Not built yet....I drew the layout on paper. I can't get this software to work on my computer. Still trying....

    I plan on socketing the left side components to swap around using the tonestack calculator. THANKS MIROSOL! I learned more about stompboxes from this exercise than I ever have just building the layouts. (Keeley 4-knob Compressor, Klon Buffer, Wah Buffer)

    I'm ready for number 4! My sound is getting closer and closer with every project!

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  15. Got the software working and drew it up. I posted it (unverified) in the forum open chat if anyone wants it. I am really digging that tone stack calculator

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  16. Can I get a schematic for this?

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  17. The schematic for the left half (the tonestack) is shown in the Duncan Tonesatck Calculator under "Big Muff". Install the calculator, run it, and click the Big Muff tab.
    http://www.duncanamps.com/tsc/

    The schematic for the right half (the LPB1 circuit) is at Beavis Audio:
    http://www.beavisaudio.com/schematics/Electro-Harmonix-LPB-1-Schematic.htm

    Miro crafted this cool combo of the two circuits, so no schematic exists. But you can do it with a little analysis of his vero layout and the two original schematics.

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  18. Tried this one tonight in a two knob fuzz variant. Fantastic! Works so good. Used a 2n5089 because it was quieter and cleaner. Maybe it was that particular transistor? I don't know. But it works great.

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  19. This is an awesome idea. I'm probably gonna try this with a NKT275 fuzz face revamp I'm thinking of doing. Might be a great add-on 'cause I'm thinking of using high gain trannies.

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  21. I've used this a few times now and made a few versions of it using the tone stack calculator. On it's own this is just god awful as I hate scooped mids but it can be modified to just about anything. The concept is a godsend. I just did a germanium fuzz face which had this tonestack with a tube screamerish mid hump and it came out just amazing. Highly recommended!

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  22. And if i just want the tonestack but without the booster? Is there something like that?

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    1. Just include the two caps and resistors on the left and remove all other components including the trimmer so the board will only be 4 x 7. The output of the circuit is then the Tone 2 lug of the pot so you can also omit the Tone 2 wire connection to the board.

      But this ton stack will give you a 7dB drop in volume without the LPB1 gain section so you'll only want to use it with an effect that has plenty of volume already.

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  23. I frickin' LOVE this circuit. I just put it after the Keeley Katana I just built and wow - it makes loud as he|| -

    I would like to get more treble out of it. I consulted the Duncan Tone Calculator, put in lots of variables, socketed the caps and tried some changes - but nothing really made a huge difference. It also seems like I can't get quite enough treble.

    I would love to see other stacks done as well. - By the way, why is it called BMP (what is the P?)

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  24. With the Duncan Tone Calc. Notice the big difference it gives you for linear vs log taper pots - a different world. Does that seem right? Could the 100k trimmer in this circuit be causing a loss of treble if it is audio taper (I am not sure what it is, I have to look it up).

    By the way, nevermind BMP, I see Big Muff Pi

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  25. Hi guys

    Could I use this as an LPB with tone control?

    Also if I take out the 100nf to base and link could I put the input caps on switch??

    Thanks in advance

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  26. Well to answer my own question yes you can...

    I built this took out the 100nf to base replaced with a link. Put 100nf and 22nf on a on/on switch and there you have it...mids or treble boosted.

    I changed the tranny for a old Phillips 2n3904 I got on eby and I have one great sounding boost......

    I am thinking of adding some clipping diodes but when I had it on the bread board there was to much of a volume drop.

    I understand that the diodes will alter the volume as they clip the signal....Would adding another LPB 1 with a fixed volume and a 2n5088 tranny fix this... Plus thanks for this site I seemed to have stopped value matched cloning and started tweeking..lol

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  27. I'm thinking of putting a pedal together consisting of a Lovepedals Super 6, followed by an Electra Distortion/EM Drive. The Super 6 is used a a booster for the electra, so it won't always be on. Do I put the tone stack in between the two schematics, or does it always belong at the end of the chain? When the boost (Super 6) is not used, the tone stack is the first in row to receive the guitar signal, is that ok? Should I install a buffer in front of it, like a Cornish one, which by the way sounds great in front of the Electra circuit..? Any idea's?

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    1. depends on what you want the tonestack to do. if you put it at the beginning of the circuit you will be altering the tone of the signal going into the Lovepedals Super 6, and will really be altering the frequencies that are being effect by the Lovepedals Super 6 when it's engaged, or going into the Electra/EM. if you place in between the two you will be altering the tone going into the Electra/EM, and alter the tone of the frequencies being effected by the Electra/EM, and your guitars pure signal going into the Lovepedals Super 6. if you place it at the end, so after the Electra/EM you will have your pure guitar signal going into the Electra/EM, as well as the Lovepedals Super 6 when it's engaged, and be altering the frequencies that are leaving the effect.

      in the end it's up to you. i would breadboard it and see where you like it best, but most effects have the tonestack at the end of the circuit so you're tailoring the signal after it's been distorted/over driven.

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    2. Thanks for the advice! I gave it some thought and think I'll first try it at the end of the chain. And you're right, breadboard is the way to go.

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  28. Hey thanks for the layout! I had a question about putting this into the original proco Rat layout from this blog. How would I have to deal with 9v and ground? My procorat layout works fine but I'd like more control over the tone. Would I just daisy chain the 9v going into the Rat circuit (split the cable to the BMP circuit before the Rat)? And where would it be best to ground the tonestack circuit to? Thanks in advance!

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    1. Never mind, I hooked it up to my rat with alligator clips and yes it works wonders. Now I'm just curious about how to attach a footswitch (and what kind of footswitch) to bypass or activate the BMP tonestack circuit...

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    2. take a look at the offboard wiring. i would think you can just wiring it up the same way you would wire 2 effects in one enclosure. the first effect would be the rat, the second would be the tonestack.

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  29. Thanks Zach, I'll give that a go. I think itd be cool to have the BMP tonestack to work as a standalone too so I'll probably use the dual effect wiring diagram. I'll update once it's done :)

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    1. yea man. if you use it as a standalone it would basically be a passive tone control with the LPB-1 as gain recovery to prevent output loss.

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  30. Hi there ! I find the tone a bit too bassy, which cap should I tinker with to fix that ? Thanks !

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    1. Try reducing the value of the 100n between tone 2 and the base

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  31. Hey everyone, I would like to add a trimmer to this as I'm adding to an existing pedal and don't want to add pots to it. Would I add a few links and switch schematic to 3,2,1 on the tone control? And move 100nf and 39k to row 2 and the 10nf to row 3? Thanks everyone!!

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  33. WOW!! I just added this little monster to the BJFE Blue Barefoot Pink Purple Fuzz and it's what I always wanted. An over the top, not tone sucking, in your face, cutting through your brain, solo/treble booster that is soooo tweekable I can't stand it. I am gonna build 76 of these and add them to every OD/DIST/FUZZ I've got. If you don't hear from me in 99 and one half days please mail me a sandwich!

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  34. M. On a typical 'vol 2 to output' pedal would this be put between the vol 2 lug and the out jack hot?

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    1. Vol 2 would go to input of the tonestack, and then output from the tonestack would go to output jack ring or 3pdt footswitch.

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  35. Hi M.
    When dealing with an effect that has 'output >> vol 2' i.e no output wire to the 3pdt.
    Would the correct routing be; input of the tonestack board to the 3pdt in, then the tonestack out to vol 2?

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    1. It really depends where you want to have the tonestack - before your main circuit or after. I'd personally always put it after. Check the offboard wiring on this page and follow the diagram.

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    2. Hi Dead Eye. Which offboard diagram? Can you please give me a point to point text to insure the tonestack gooes AFTER the main brd. I am confuuuuuzed about the vacant 3pdt lug and/or the vacant o/p jack 'hot' lug. I'm putting this on a TC Elec Octave circuit that I love and want to maximize the output.

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    3. Just take the output from the main circuit and connect it to the input of the tonestack, then the output of the tonestack becomes the output to the switch. The trimmer on the tonestack will be used to boost the lost output from the tonestack.

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  36. Put this on a Dod250.. so good. Was a great OD to begin with, but with a little added tone control it fits all my guitars better. This is a good one. I built it originally to pull some of the mud off the Robot build. That worked nice too.

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  37. just used it with a modified jfet vulcan od with j202's and some added gain and voltage. sounds so much better with this thank you!

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  38. Hi,what is Zsrc (in the tonestack calculator)?where is on the board?
    thanks

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  39. this project is great was thinking to do this for a while,
    if i want to make it as stand alone pedal,
    Do i have to ad a coupling capacitor( for example 0.1uF) and a resistor as a high pass filter (43k i took those value from the lpb1 circuit analysus from Coda effects website)

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  40. Hi all! I'm having some trouble with this circuit. I have it hooked up after a Colorsound 1 knob fuzz I built (going for a two knob vol/tone type setup) but I can't seem to get it anywhere near unity volume without an awful feedback. The 1KF circuit is essentially the DAM Meathead with a few value changes (and a trimmer instead of a bias resistor) that worked no problem before I added the tone circuit. I have the trimmer on the boost section as low as I can and still have signal from the fuzz pass through and it still feeds back BAD. I'm about ready to just ditch the layout and go for something else (maybe a mkiv bender with an internal fuzz trimmer?) but at the same time, I'm too stubborn to know when to quit. I appreciate any insight!

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