I got a request for a layout of the Big Muff that could be used to build the Triangle, Rams Head, Green Russian, or NYC versions. While it shouldn't be that hard to take one of my previous layouts of the BMP and make the value changes, I thought I'd make a more detailed project than I normally do. First, let's start with the schematic. This is the basic circuit used by pretty much every variation of the Big Muff (excluding the IC Big Muff):
The only difference between versions is a handful of component values. Generally, the circuit was tweaked to work with whatever Mike Matthews had on hand. As a result, there are about 18 different variations produced by Electro-Harmonix. Now, not all of those variations sound all that good. But over the years several really good sounding Muffs have been traced and their component values posted on the web (mostly on Kit Rae's awesome
Big Muff site). The 4 versions specified in this project seem to be some of the most popular and best sounding Muffs.
The component names in the schematic above correlate to this layout:
For a full BOM for all 4 versions, download the file linked below. In addition to the BOM, it contains scaled transfers for etching your own circuit board, as well as a scaled drilling template for building the effect into a Hammond 1590B enclosure.
If a BMP variation you want to build isn't specified in this project, use the above schematic and compare it to the schematic of your desired version to figure out what components go where.
Updated Sept. 2, 2015 to correct schematic, placement of Tone pot, and drilling template.
Awesome project..I think I will try)
ReplyDeletethank you
ReplyDeleteThis is such a awesome work! Thank you so much for share this proyect with us. I'm sure that this will be so useful for a lot of people.
ReplyDeleteKeep doing it like this! Cheers from Chile!
Awesome project. I would only mention that on the schematic, C7 and C10 are kind of on the wrong side of the clippers. Dont think it would affect. On the leyout it follows the original schematic but if you check whith the one you show it messes that place. Awesome project again!
ReplyDeleteC7 and 10 can be on either side of the clippers. There are several iterations of the BMP with it either way. It has no real effect on the sound. The layout predates the schematic I drew up. Apparently I was just following a schem that had it differently.
DeleteHey guys,i've just finished BMP version and it works and sounds fantastic)Tnx for awesome project)
ReplyDeleteBig Muff pi, Triangle Big or Muff 77 OpAmp for David Gilmour sound?
ReplyDeleteHe's used a couple different ones over the years. I think Kit Rea's Big Muff site has a whole write up on what he used. I think he used a Ram's Head and Civil War. Probably a few others too.
Deletethanks brother, nice info.
DeleteHello you would not have the layout of Pharaoh Fuzz, to provide for us? I have the scheme How can I send you? Thank you man
ReplyDeleteI'm actually in the middle of laying that one out, so stay tuned!
Deleteok thank you , I follow every day the Blog, sensational
DeleteHi, im doing the nyc, the resistor omit it's just a jumper? and on the 1u Caps should i use polyester or ceramic?
ReplyDeleteGreetings.
Don't use a jumper, just leave that spot empty. And it's up to you on what kind of caps. EHX has used both kinds over the years. I would probably go with ceramics as they'll probably fit better on the board. Good luck!
DeleteThis big muff ... is 1/2 Watt or 1 watt ... polyester or ceramic ??
ReplyDeleteWow awsome ,sorry for my question.
ReplyDeleteBut how to do an bypass? simple put a switch in front of the input, and switch it direct to output?
And another question is. Why there are 3 ground points?
And where to put the "-" from the 9v battery?
Sorry for my dump question but iam complete new to that kind of stuff.
Lots of ways to do bypass switching. There's a simple way that's shown in the General Layout Note tab at the top of the page, and many more can by found with a google search. The extra ground pads are just to have extras.
DeleteHi, could you tell me the dimensions of the pcb layout?
ReplyDeletewhat transistor replacement can I use on the green russian?
ReplyDeleteTransistors don't really play a huge part in shaping the sound of really any version of the BMP. Pretty much any medium-high gain NPN silicon will work. 2N5088, 2N5089, BC549C, BC550C, MPSA18, etc.
DeleteHi, I built the Rams Head version. I was hearing a lot of clipping at Q4 and I asked at diystompboxes. There is a discussion around the values of R20 to R23 as shown in BOM. http://www.diystompboxes.com/smfforum/index.php?topic=119755.0;topicseen
ReplyDeleteHi, where can i find the BOM, in the link just have a description and the schematic, but with the parts named as C1, R1, etc... not the values... Thanks for your work.
ReplyDeleteClick the link and scroll down
DeleteI want to do the NYC version but in R8 it says "omit", what does it mean? Do I need to replace it by a cable bridge or leave it empty that holes?
ReplyDeleteOmit = leave out
Deletelooking at the scheme r8 place seems critical to the flow of signal
DeleteIt's actually R9 you omit in the NYC
Deleteooh you are right, sorry and thanks
ReplyDeleteJust for sure, on the project do you use a dpdt, not a 3pdt, is that right?
ReplyDeleteIs R24 the LED resistor or do I need to add one?
ReplyDeleteYes, R24 is the LED resistor
DeleteHello! One doubt...
ReplyDeleteAre the pots supposed to be upside down or I am misunderstanding the thing?
Yes
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DeleteHEY! I'm finding Vc=1,1v in the Q2 collector. Is it supposed to happen? The other Q's are Vc=4,4v.
ReplyDeleteVerified
ReplyDeleteNyc bigmuff
Used all pots B100k
I made 2 of these using 4 x 2n5088
ReplyDeleteAnd 4 x 2n3904
Both works
But when i turn all knob up there is squeeeling noise
Pedal works fine but noise
I have the same problem, when tone and volume knob is above 70% it makes this noise, I have to turn down one or the other
DeleteHi, could you tell me the dimensions of the pcb layout?
ReplyDeleteThe 1N4001 diode is the only component I'm missing and don't want to wait for delivery around the holidays. I have old 1N5353b or 1N746A that I'm wondering if either will work. Not fully understanding the datasheets but I don't think either will work from my googling.
ReplyDeleteIf you used 4148s for the clipping diodes, you can use one of those in place of the 4001. Those other 2 are zener diodes and won't work for this application
DeleteThis comment has been removed by the author.
ReplyDeleteHi, sorry but all of the links (dropbox) is not working/dead, can you fix it? thanks :D
ReplyDeleteRam's head works, but i have a noise issue when tone and volume all way up. Did anybody find solution to reduce that problem? I did not find yeat.
ReplyDeleteHello, my question is whether the following capacitors can be used as electrolytic capacitors since I don't have the ceramic and polyester ones
ReplyDeleteI'm talking about the NYC version.
C1
C3
C5
C8
C14
I have the electrolytic ones and they are 1UF but I don't have the polyester and ceramic ones.
Is there any problem if I use them without respecting their polarity?
Electrolytics are fine there. Positive side toward the closest transistor. So...
DeleteC1 + toward base of Q1
C3 + toward collector of Q1
C5 + toward base of Q2
C8 + toward collector of Q2
C14 + toward collector of Q4
Hello! I have built the NYC version and it sounds amazing! But it is popping everytime I press the switch, is there a way to eliminate that?
ReplyDeleteI did some research and i would like to update what i have done so far:
Delete- Raised R1 to 2Mb - no success
- Put a 1Mb pulldown resistor at the output - no success
- Disconnected the led - no success