ELECTRO-HARMONIC x JHS: Big Muff 2

It's been a while - and I've probably scared most of you away with obscure amp content, but I have to have a crack at this one.   

Yes, it could have been a smaller layout, but to be honest, I'd still be adding some room around the edges for proper mounting points.  I also left room for a 1meg resistor on the input, if you are that way inclined. 

The schematic can be found here, which is apparently printed on the box.  If you don't have the exact values, use the nearest available (4n7 instead of 5n as an example).

note:  Volume pot is actually B10k. will update the layout later, 100k will still work fine

ELECTRO-HARMONIX x JHS -  BIG MUFF 2 VERO LAYOUT

Big Muff Fonts - Vintage

Vintage big muff fonts, these are generally available for download.  Please note that EHX is known to be very protective of their brand. 

Arnold Boecklin

Devinne:  sustain, volume, tone

Futura:  on, off and made in U.S.A

Skjald:  Electro Harmonix

ITC Pioneer

Not exact, but pretty damn close.  The M needs a slight drop on one side, which would not be hard to do with fonts converted to vector.

PETE CORNISH: P-1

I'd created a layout for the Pete Cornish P-1 about four years ago, based on best guesses as to what this said to be - a Rams Head Big Muff.   I was kind of close, but here's a layout from a very reliable Aion FX trace.  If you want to see where it sits in the spectrum of the Big Muff, check my BMP components table.

Interestingly, the circuit matches the 1976 Rams Head circuit #2, despite stories of it being based on a 74 model.  Who knows?  It's quite possible this was the case for the original P-1 with Pete changing values at a later date.

PETE CORNISH: P-1 VERO LAYOUT

Yes it's a very big layout for a Big Muff.  I included all of the buffers on the board, and left room on the corners for mounting.  I'm sure the multitude of standing resistors will throw a lot of people off too.  I clearly don't mind them.

I wasn't all that concerned about size, as I intend to drop this into an old big box BMP enclose, as beat up NYC ones seem to be going pretty cheap, and of course they already have cool graphics, pots and a hardware ready to go, so job done in that respect. 

PETE CORNISH: G-2, 2012, Battery Free Version (Aion FX Trace)

There's been so much speculation about the G2, over many many years.   Aion FX has traced two versions of the Pete Cornish G2, so hopefully this is the end of some very long threads on various forums.  

Long story short, one version is very close to all of the mods that everyone has been doing for years.  Here's the battery free version, which uses a mix of germanium and silicon diodes, and has smaller caps in the required places to fixe the darkness issue.   

I will come back to this at a lter date with more details and a larger layout incorporating the second buffer.  This is it for now...  

PETE CORNISH G2 - AION FX TRACE, 2012, BATTERY FREE VERSION

PETE CORNISH: P-2 (Aion FX Trace)

So the mysterious P-2 has finally been traced, care of Aion FX (thank you).   I had previously posted a guess as to what this might be, and I wasn't too far off.   Here's the same layout with confirmed values.

PETE CORNISH P-2 - VERO LAYOUT

ACE TONE: FM-3 Fuzz Master

I'd somehow missed this one.  The Ace Tone FM-3 Fuzz Master is similar to the Ace Tone FM-2 in looks and name, but that's where the similarities end.   The FM-2 is based on the Univox Super Fuzz and the FM-3 is a Big Muff variant.

Schematic can be found here on Kit Rae's BMP site.  Basically take a Big Muff, and add an additional tone control with its own volume pot attached to it, then switch between the Big Muff circuit and the boost circuit.   No you cannot route one in the other, as they share input and output sections.  Nice idea though...  

The tone controls are a little different, as they use a combination of values not found on any of the many EHX circuits.  There's still the scoop, but it just has a different response.  I haven't compared it to a Big Muff, as which Big Muff should it be compared to?

For those with keen eyes, yes the resistor in the collector of Q1 is really 150k, not 15k as one might expect to see.    I'm not sure about the 100k on the input to ground either, but it was on the traced version found on FreeStompBoxes - link to the thread and schematic here.  It's not on the Kit Rae schematic.  

ACE TONE FUZZ MASTER FM-3  -  VERO LAYOUT

COLORSOUND: Jumbo Tone Bender

Surprised that I hadn't done a standard vero layout for this earlier...  The Colorsound Jumbo Tone Bender is just a Big Muff missing some diode clipping and the last boost stage (the lack of diodes in the first clipping stage makes up for the lack of boost).

They share nothing in common with their predecessors of the same name, not that Tone Benders MKI, MKII and MKII had any fundamental similarities.  They aren't for everyone, as they can sound quite raw on guitar compared to a regular Big Muff.

The 3n cap in the tone section is sometimes seen as slightly different values - being a BMP tone stack, it's easily modded to suit your taste.  

COLORSOUND JUMBO TONE BENDER -  VERO LAYOUT

ORIGINAL SCHEMATIC

VIDEO DEMO

COLORSOUND: Jumbo Tonebender

Not really a Tonebender; it's really a Big Muff in disguise - minus a couple of diodes and a gain stage.

These were built in the 1970s 

 

COLORSOUND JUMBO TONEBENDER - VERO LAYOUT

COLORSOUND JUMBO TONEBENDER - VIDEO DEMO

EARTHQUAKER DEVICES: Hoof Reaper

I know one could make the three different effects and box them together, but I thought I might do a layout with them all on one board.  

EARTHQUAKER DEVICES HOOF REAPER - VERO LAYOUT

REAPER VIDEO DEMO

ARIA: Super Fuzz Sustainer

The Aria Super Fuzz Sustainer is a variant on the Big Muff, probably based on the Elk Sustainar as it shares the same values mostly (based on a Triangle BMP).  

The tone stack is a bit different, and it's clearly missing a recovery stage at the end, not unlike a Colorsound Supa Tone Bender.  Unusual to see the 6n8 cap and 100k resistor before the tone stack as well, as this reduces the overall output - given there's no gain recovery stage, this is probably not ideal.  Bypassing or removing the 6n8 / 100k resistor doesn’t appear to affect the output response, but it does provide a large jump in output level.

ARIA SUPER FUZZ SUSTAINER - VERO LAYOUT

ARIA SUPER FUZZ SUSTAINER - SCHEMATIC

Schematic from the thread on FSB

Pretty similar to a big muff, but with a lower frequency mid-range scoop

ARIA SUPER FUZZ SUSTAINER - VIDEO

EARTHQUAKER DEVICES: Hizumitas Fuzz Sustainar

The Earthquaker Devices Hizumitas is basically the same as the Elk Sustainar, but with a 3n3 cap instead of a 330pf cap in the tone control (specifically the high pass filter).  There are some other minor differences, but the 3n3 is probably the biggest factor in terms of sound.  

Even though the EQD Hizumitas is based on the Elk Sustainar, the Elk was based on a 1972 #2 Triangle BMP.  Check out the schematic on Kit Rae's site, and note the similarities.  

So with all the hype surrounding this release, this is actually much closer to an EHX Triangle Big Muff from 1972 than it is an Elk Sustainar.   

Update:   After a few weeks away, I finally got around to finishing this and trying it out.  I don’t like it.  Too much bass for me, and I didn’t find that it had much range.   

EARTHQUAKER DEVICES HIZUMITAS FUZZ SUSTAINAR - VERO LAYOUT

Of course, I started building only to discover I have no 82k and 8.2k resistors…  3n3 cap is not soldered on at present, as I want to test some different values.

EQD HIZUMITAS SCHEMATIC

TEARDOWN BY GRAYBENCH

HIZUMITAS VIDEO DEMO

DEAD ASTRONAUT: X Fuzz

I thought while I was at the Dead Astronaut X Rock, I may as well do an X Fuzz...   It's a nice easy pedal build, with some big sounding results.   

DEAD ASTRONAUT X FUZZ - VERO LAYOUT

DEATH BY AUDIO: Fuzz War V2

The first version of the Death By Audio Fuzz War is notoriously tricky to clone - this is the second version, which is a modded Jumbo Tone Bender with a tweaked tone stack.  So, in other words, it's a modded Big Muff.

Schematic / build docs at PedalPCB

DEATH BY AUDIO FUZZ WAR V2 - VERO LAYOUT

COLORSOUND: Bass Fuzz

The Colorsound Bass Fuzz is a Big Muff style circuit, missing a pair of diodes and the gain recovery stage, not unlike a Jumbo Tone Bender.  Caps have been enlarged to suit the bass guitar.

COLORSOUND BASS FUZZ - VERO LAYOUT

Electro-Harmonix Big Muff Pi Schematic and Component Table

I used Kit Rae schematics, but I did not follow the same component numbering, as I don’t find it all that intuitive.  Kit did it that way for a good reason, this way works better for my brain.  There's also this excellent post by Kit Rae on the EHX forum, broadly describing differences between versions.

GENERIC BIG MUFF SCHEMATIC

ELECTRO-HARMONIX BIG MUF PI COMPONENT VALUES TABLE

link to table

GENERIC BIG MUFF LAYOUT - WIDE

If you want to add power filtering, just add an extra row at the top - if you're read this far, I'm sure you can work it out.  

GENERIC BIG MUFF LAYOUT

There's room for the tone pot to be wired on the sides of the vero board, I prefer them to be together, which is why they're popping up out of the middle of the board at the top.

There's enough room on this to add power filtering and polarity protection down the centre two rows (where V+ and ground is).  

GENERIC BIG MUFF SCHEMATIC WITH CAPACITOR POLARITY MARKED

BUILD TIPS

There are no magic parts in a Big Muff.  It's a well designed circuit and the fact that so many value changes occurred over time and it still sounds like a Big Muff is testament to that.

Transistors

Don't stress about getting the "right" transistors.   There's really quite minimal differences between most transistors - certainly don't spend a lot of money on rare / vintage for a Big Muff.   I know there are lengthy online discussions around what the right hfe is, after spending a lot of time testing on a breadboard with guitar in hand, I decided that it doesn't really matter that much.

Diodes

Again, subtle differences for the most part.  Practically any small signal silicon diode does the job.  

Resistors & Capacitors

Values are important, the type is not.

I will say that some of the odd values seen on the filter section are worth trying to attain.  example 4n and 12n.  If you substitute different values, it will obviously still work, but it doesn't sound the same - the filter section is such a big part of the Big Muff sound.

IBANEZ: Overdrive OD-850

The Ibanez Overdrive OD-850 is an early Japanese Big Muff variation, almost a straight clone if it wasn't for the usual tone stack.  It's also known as the Maxon D&S OD-801 - either way, both classic guitar effects from Japan.

The tone stack fixes the bass response to some degree, providing a more even sweep across the range.  

Note that it asks for a C828 transistor, but I have used the pinout for a standard CBE transistor.  828s are usually BCE.  

IBANEZ OVERDRIVE OD-850 - VERO LAYOUT

PETE CORNISH: NG-3 Fuzz

This has now been traced by Aion FX - it turns out the NG-3 is very different to the NG-2.  Miles apart...  

While this still makes for a decent fuzz, it's NOT a NG-3.  Layouts have been removed for this reason.  

Here's the link to the trace

The Pete Cornish NG-3 is pretty much the NG-2 with the trimmer to bias the last stage placed externally - which is a great addition, even if the knob count starts to get a little high.

The front end is the first section of the Cornish G-2 (a low-gain Big Muff with germanium diodes), and the last stage is a Fuzz Face variant.  

This should be built with the usual Cornish buffer, running buffered bypass.  Hardly the end of the world if you opt to use a standard unbuffered true bypass.   

As I've never seen a schematic for the NG-3, this is my work-a-like.  I've used a 25k pot as the bias pot in my builds, as I preferred the range.  I have had someone else say that they preferred the 50k, and another used a 20k pot without issues.  Either way, it's best to have a low-value resistor at the end of the range to stop the circuit from completely turning off - I use 4k7 for this, 8.5k has also been reported as a good value.  

PETE CORNISH: P-2

It has now been traced by Aion FX - updated layout can be found here.

The Pete Cornish P-2  is somewhat of a mystery as it's never been traced, so all information is gleamed and guessed from various sources.  It seems that no one, including myself, wants to pay top dollar to de-goop what we all know is some kind of Big Muff. 

So what do we know?

• it uses the same PCB as the G-2 (photos here)
• silicon diodes
• double buffered
• the tone control is a low-pass filter, not a standard BMP tone stack (description here, listen here)
• reportedly first made in the eighties, before Big Muffs from the former Soviet Union appeared on the market in the nineties

So this leaves the P-2 reasonably open to interpretation in many regards, but there are parameters to work within that will get you in the general area regarding sound.  Pete Cornish was working with David Gilmour, who liked Rams Head Big Muffs.  Kit Rae describes the V2 1973 #3 Rams Head Big Muff as the closest sounding to the tones Gilmour produced and very similar to the P-1.

Kit Rae sound comparisons below - to my ears, the P-1 and P-2 sound very similar in gain/clipping; the main difference seems to be the tone control.

P-1, P-2 and G-2 chords

P-1, P-2 and G-2 tone pot sweep

To make things a little more interesting/confusing, here's a gut shot from an early Pete Cornish pedal before he started gooping circuits and including double buffers.  They're calling it a P-2, but I think it might be an old P fuzz - who knows...  The board is laid out the same as the G-2, but you can see 2 x capacitors in the tone section instead of just the one - so this seems to have a traditional BMP tone stack.  There are also a lot of 220n MKT caps visible, following the same pattern as the G-2.  

PROBABLY NOT A P-2, BUT MAYBE IT'S CLOSE ENOUGH VERO LAYOUT

This is how I built my P-2, which is 100% guaranteed to not be an actual P-2...  but it will get you in the same area.  It has plenty of gain on tap; it could perhaps even do with a little less - maybe increase the emitter resistors a little.   

Update:  I did reduce the gain structure a little by increasing the emitter resistors and decreasing the collector resistor on the last clipping stage.  Not a massive difference, really.  Subtle, yes; game-changing, no.

Please remember that the tone control is a low pass filter; setting it to the centre like a typical Big Muff is not the best place to start.  Start with it open, then roll it back to tame the highs.  Don't forget to put the Cornish buffer in front of this too.   

Layout removed, as values have now been confirmed (I was pretty close)

ON THE SCOPE / FFT

Signal:  440hz sine wave, approx 130mv TRMS

 

Boost stage, Sustain 100%

First clipping stage, Sustain 100%

  

 

 Second clipping stage, Sustain 100%

 

 

PETE CORNISH: G-2

The Pete Cornish G-2 is a Big Muff variant:  germanium diodes, double buffered, and sporting a low-pass filter instead of the usual Big Muff tone stack.  

That being said, this is not your standard Big Muff - there's little resemblance in sound, largely due to the lack of scooped mid-range provided by a standard Big Muff tone control, and the germanium diodes change the clipping profile quite a lot.  Do not expect this to sound like a Big Muff.  

There are so many opinions on how this should be built - but keep in mind that the same topology is used for any variation.  The main complaint is that it's too dark-sounding using stock values, so builders try to address this by making various changes.  

Now we have some new traces from Aion, which probably puts all of this to bed.

Some people change the diodes too, but once you get away from germanium diodes, you may as well make a Pete Cornish P-2.  Pete Cornish uses the same PCB for both; one uses silicon diodes and is supposedly based on a Rams Head-era BMP. The other is closer to a BMP from the former Soviet Union but with germanium diodes (or perhaps glass-encased Schottky).

The layout below has the same values as the Dirk Hendrik trace; alternate values are all listed below.  I'll update shortly to the Aion trace, bit for the moment, you can work it out or head on over to Dirt Box layouts.

This needs the standard Cornish buffer in front, and should be wired as buffered bypass if you want to stick to the Cornish program.  If you don't plan on using the buffer, it's probably a good idea to drop that 220n cap on the input back to 100n.  

NOTE:  It does have one buffer on the board, as the G-2 is double-buffered.  

PETE CORNISH G-2 - VERO LAYOUT

The odd coloured lines running across the vero board are power and earth - ignore...  nothing to do, just a little visual helper for me that I used to include on my layouts.

PETE CORNISH G-2 BUILD PICS

Initially, I built this with 2N5088 and BC109C transistors, so if they look the wrong way around compared to the BC549s on layout, that's why.  I ended up swapping the B109Cs out for standard transistors, as they weren't really doing anything special - not even sure why I put them there to start with now.

I dropped the 4u7 coupling caps down to 2u2 and the 1n caps to 510pf caps across collector and base.  I used 1N277 germanium diodes with 220n caps in the clipping section to retain the primary character of the clipping sections.  

It sounds pretty good - I like it more than the stock values for chords.  I find that this pedal appreciates running at a decent level, and it's very dynamic compared to a Big Muff (probably due to the lower gain / less clipping compression).  At wife is at home levels, it sounds constrained, at least to my ears.

It does great lead tones with the stock values, it's rounded and smooth, and is probably not one for the speedy shred masters out there.

Chords are hard to describe as it's so touch responsive - moderate gain levels seem to suit chords better than the higher gain settings.  I found the tone control (low pass filter) is only needed for bridge pickups.  

PETE CORNISH G-2 - SUGGESTED ALTERNATE VALUES (BY OTHERS, NOT ME)

• 10n cap on the input buffer - reduce to 1n (brightens the signal from the buffer)
• 220n caps down to 100n
• Collector and emitter resistors on input boost stage, change to 18k and 100ohms
• Reduce 4u7 caps down to 2u2
• All 1nf caps down to the standard 470pf Big Muff values

You will undoubtedly find more via some googling, along with the heated debates.

CATALINBREAD: Manx Loaghtan

After the Thorpy Fallout Cloud, I thought I might do another bax Big Muff.  

The Catalinbread Manx Loaghtan pre-dates Thorpy's by quite a few years.  The same basic idea, take a Big Muff and swap out the single tone control for a baxandall tone stack.

CATALINBREAD MANX LOAGHTAN - VERO LAYOUT

EQ CURVES