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This is the continuing progress of the Big Muff Pi (David Gilmour circuit) effects pedal. In the previous blog, I thought I'd give you a back story and a potted history around the Big Muff how David Gilmour started using it and also the variability of these pedals, but now I want to get into the building of this pedal proper. I now have all the components except the enclosures (I'll buy them later once the boards have been built and tested) so now all is to be done is etching the boards.


To recap the circuit is based on a schematic that was traced from a pedal that was tested by Kit Rae, in which he identified this particular circuit as the closest in his opinion to the one that has been used by David Gilmour of Pink Floyd from around 1976/7 to the present day. I'm interested in what this sounds like and can't wait to hear it. Apparently this is similar to the Pete Cornish P-1 Custom Fuzz which was Pete's variation of the the Big Muff circuit but with enhancements. we don't know what the circuit is like in the P-1 as it's sealed by Pete Cornish to prevent nosy people stealing his circuit layout. But what we do know is it's heavily based on the Big Muff, and was designed at the time to be an alternative to the EHX Big Muff which David was using at the time. Therefore the sound of the P-1 was designed to be as close to Davids Big Muff as possible.


KR_1973_V2_No 3 Schematic (GILMOUR).jpg


Both boards have been etched, and now starts the laborious task of drilling the holes........ I hate drilling the holes, as I'm doing them by hand. I need to invest in a Dremel and a stand to speed the process up. Following the etching process you can see that there are some tracks on one of the PCB's that has some breaks on it. In this case I'll bridge them with solder and/or some spare leads that I saved from previous builds. On all my builds I save the off cut component leads. These come in really useful for extending terminals (like on the pot terminals for the power boost), also they're invaluable for repairing broken tracks as in this case. Hopefully i'll be able to just bridge with a little solder, but if the gap is too much, I'll solder in some wire to bridge the gap. Either way, It's an easy fix.


EDIT - 11th Nov 2017: It's now quite a few weeks since the above paragraph was written (I've been ill, as well as other family orientated issues), and I've decided to buy pre-fabricated PC boards. I just wasn't happy with those boards I etched, too many breaks and the tracks looked iffy. They just looked unprofessional and i'm presenting one of these to a professional musician so I want to ensure they look right not only on the outside, but on the inside too. Attention to detail with these pedals is key, and although the pedal I'm giving him will be set up to only use a 9vDC power supply, so he'll likely never open the case up as he won't be changing batteries.... I'll know it's not right. I suppose it's the perfectionist in me coming out


So the boards I'm using are supplied by a company called Pigeon FX. They not only make their own vintage pedals like I do, but they also have vintage design boards fabricated exactly the same as the originals, so this is what I intend to use for these builds. Also, the holes are pre-drilled so that saves me that headache. These boards are available on EBay, for a not unreasonable price... As soon as the boards arrive, which hopefully will be in the next day or two i can then start immediately populating the boards. What i'll likely do is populate one board, test it then use that as a template to populate the second board. Work in progress photos to follow

As a guitarist I'm always chasing "tone"... looking for those elusive sounds that makes the hair on the back of your neck stand up. Through the years I've been in many bands, notably a few Pink Floyd tribute bands, and during my tenure in these bands I struggled to achieve the sounds I was searching for, I got close, but there was always something missing. As you can imagine, playing lead guitar for a Floyd band is no mean feat, and takes a lot of planning. Each song is crafted, and moulded from many different effects, and colours... Back in the day I struggled to achieve these sounds by using run of the mill effects processors which for the uninitiated are very powerful digital effects units that have many different sounds that can be programmed and stored in any combination. For example, I could program reverb, delay and distortion into a preset in the unit. During a performance I would tap a button with my foot which would call up that preset number, and in turn all those effects would come on at the same time..... That's layman's terms. Effects processors are great, I still use one but I miss the old days of "stomp boxes" as they give you the true sound of what David Gilmour did back in the day, there is a marked difference between a proper analogue pedal and a digital "copy" for want of a better word. Where digital gives you a super clear signal and digital clarity that can't be put into question, true analogue pedals give you the warmth and dynamics that digital just can't give you. When you're playing Floyd you really need both as through the years David Gilmour has embraced both old technology and new technology (just looking at his enormous guitar rig demonstrates this) and that was my issue back in the old days....... I didn't have both, I just had the digital processor. 3 years ago I made the decision to turn my back on music.... I sold all my equipment except my guitars, and decided that I'd retire from playing in bands, my wife said I was mad and would regret it, needless to say I said "No i won't".... How wrong I was.


3 Years later, at the end of 2016 I was climbing the wall as I was missing playing. I realised that i was wrong and she was right. I now think I was just in a rut, and needed a break. Anyhow, I decided to replace all the equipment, but this time do it properly. I've now rebuilt my whole stage rig to incorporate both modern technology with the digital effects processor, but also have an elaborate switching system so that I can run old school effects pedals with the digital stuff simultaneously. I can now stretch my legs and build these pedals that should nail the sounds I've been chasing for so long... So far I've been happy with the results and as these blogs go on the builds will get ever more complex. I've started off easy with the fuzz face and the power boost which were fun pedals to build, and later on I'll be getting into the realms of modulation pedals like the Uni-Vibe the Phase 90 and the Electric Mistress. All 3 of these pedals (With maybe the exception of the Phase 90) will be a challenge as they are technically far more difficult than most out there, but I'm sure with your support and guidance i'll succeed and we'll have fun along the way. I still need that damned Oscilloscope!


Back in the seventies when Pink Floyd were pretty much turning everything they touched into gold, David Gilmour's guitar technician Phil Taylor presented David with a pedal that would forever shape Gilmour's sound from 1977 onwards..... This pedal was the Big Muff Pi manufactured by Electro Harmonix (EHX).


Up until then David had been using the Fuzz Face on pretty much everything from when he joined the band in 1968 (he used a Germanium Fuzz Face at this time), and then moving onto the Silicon Fuzz Face in the early 70's due to the instability issues with Germanium transistors. The Fuzz Face helped sculpt his sound throughout this period, and when Phil Taylor joined the band as Gilmours guitar technician in 1974 he started making suggestions to David as to possible improvements to his sound. Phil Acquired a 1973 version 2 Big Muff for David in 1974, however he didn't use it straight away, and it was shelved until around 1976 when Pink Floyd started writing and recording what would become the Animals album. He then tried it, and used it to huge effect on the Animals album, and the accompanying "In The Flesh" tour.


When i started this venture of pedal building, I had my sights set on building the two "Holy Grail" pedals, the Electro Harmonix Electric Mistress which hopefully will be the subject of another build in the future, and the Electro Harmonix Big Muff Pi. For me this pedal signifies everything about David Gilmours sound from 1977 to the present day. Used in conjunction with a Colorsound Power Boost and a bit of delay the sound is huge, and for guitar solos just sounds epic.


There have been many different permutations of the Muff since it was first released... Far too many to be honest. They started in 1969 with the "Triangle" Big Muff so called because of the shape the controls were in, this pedal started out being made totally by hand point to point soldered on perf board, they then introduced "proper" PCB of sorts, the triangle had at least 5 circuit variations between 1969 and 1973, that was followed by the "Rams Head" Big Muff, so called because of the little picture on the front of the enclosure looks apparently like a sheep... Then you have what I call the "Modern" NYC Big Muff..... All these share the same basic circuit and PCB, however due to availability of components, values were changed, substitutions made and the sound therefore changed between versions, and indeed in the same run of pedals. Basically, with vintage Big Muffs you can have 2 that were built on the same day, and they can sound different.


You can learn more about these pedals by visiting Kit Rae's excellent Big Muff Page This is probably the best resource on the net for all things Muff. he has managed to list pretty much every schematic, and permutation of the Muff from the very first Triangle pedals that were soldered point to point on perf board, right up to listing some of the better clones and boutique pedals there are out there. This site goes into far more detail that I will here, and for those that are interested it has the schematics...... You'll be able to see just what changes were made to the circuit over the years, what values changed etc........ This is pretty much the single best resource and was the starting point for my David Gilmour Big Muff build.


"Triangle" Big Muff   Rams Head Big MuffModern NYC Big Muff"Civil War" Big Muff



Everyone has their own favorite, some like the triangle, I particularly like the Rams Head (but there's more to that in a moment) The modern is best left undiscussed .... I'm not a great fan, and the sound is really nothing like what I would call a Big Muff. For a period of time in the early 90's they were made in Russia, by a company called Sovtek. Sovtek made these Muffs with so called Military grade components, these are now fairly sought after as they aren't made in Russia any more. The build quality wasn't the best, and some of the components like the jack sockets were truly awful quality. One of the more well known Russian Muffs was nicknamed the "Civil war" Big Muff on account of the font and colour scheme they used on the enclosure, this was used by David Gilmour throughout Pink Floyds 1994 Division Bell tour instead of his old Rams Head.


The cost of a new "Modern" NYC Big Muff is reasonably priced at around £80, however when you get into the realms of the vintage Big Muffs you might as well have a blank cheque. Cost wise the value of these things has sky rocketed. There was a "Violet" Rams Head that recently went on Ebay for $2000 (Check this link). The joke is, they pay this money because they think they're getting a rare pedal, the truth is every Big Muff during the 70's was different to the next. No 2 muffs are the same, this is due to the "slap dash" way in which component values were used... If they didn't have a resistor of the correct value they'd just solder in one close to it. This happened all the time, and by the end you had a pedal that sonically was different to the previous one, and different to the one before that, and before that... and so on and so forth. Kit Rae has conducted some A/B testing home made Big Muffs and just swapping out the transistors, the results were that the transistors don't appear to have a detrimental effect on the tone shaping of the pedal... It's more to do with the caps etc.


In 1976 David Gilmour had started to use the Big Muff, but he'd also started to have talks with bespoke effects board builder Pete Cornish. Pete Cornish is a British designer of electric guitar effects and other electronic musical instruments. He is mainly noted for his elaborate fully custom guitar pedalboard systems. He has worked for Paul McCartney, of course David Gilmour, The Who's Pete Townshend, Lou Reed, Tony Iommi of Black Sabbath, Brian May of Queen, Mark Knopfler (as well directing some Dire Straits videos), The Police's Andy Summers, and many others.


Cornish has been described as "the inventor of the pedal board" and a key figure in the transition from single effects pedals to the development of multi-effects units. It's this multi-effects system that caught David Gilmour's eye, and he got Cornish to build for him his first effects board for Pink Floyd's Animals tour in 1977. This featured all his effects built into a custom board, with buffers etc introduced to the board to reduce RF and ground loops etc. Pete Cornish is fiercely secretive about what goes into his boards, and effects and schematic are not available for anything that he makes, they're retained by him and the effects have anti-tamper seals on them so you can't get into them. Anyway, the Animals board also featured some send and return sockets so that Gilmour could add effects to the board, this was how he introduced the Electric Mistress and the Big Muff to his rig in 1977. Later on, Pete Cornish would modify this effects board by integrating the Mistress and Muff directly into the board with the other effects as these two effects alone had started to staples of David guitar sound.


For those that are interested you can learn more about Pete Cornish and his history in electronics by visiting his site here Pete Cornish


There is also an interesting interview with Pete about the "Animals" board here Pete Cornish: Pink Floyd Relics



David Gilmours "Animals" pedal board, build by Electronics genius Pete Cornish for the 1977 "In The Flesh" tour.

You can clearly see the Electric Mistress on the left and the Rams Head Big Muff on the right, on top of the board plugged into the send/return sockets.



There are many songs that Gilmour has used the Big Muff on, and to list them would be basically listing everything from 1977 to date. However I have to choose a few that I think show the Big Muff off in it's best light. to this end here is Dogs from the album Animals in 1977 (All 17 minutes of it!!), and Comfortably Numb from the album The Wall in 1979. I have also included Pink Floyds legendary live version of Comfortably Numb from Live 8 in 2005. This was when all four original members of Pink Floyd reunited for one night only..... This version of Comfortably Numb is pure Big Muff during the long solo at the end. It also shows just how damned good this band are even after all these years..... Not bad for 4 pensioners. They certainly showed the younger bands at Live 8 how to pull off a live performance.


Dogs - Animals 1977


Comfortably Numb - The Wall 1979


Comfortably Numb - Live 8 2005


David Gilmour to this day famously uses a 1973 Rams Head Big Muff, but don't for one minute think that you can call up a 1973 Big Muff schematic and make one exactly the same, as you can't. A simple glance at Kit Rae's web site will tell you that in the Rams Head version there were at least 8 or 9 different permutations, and differences of components over the build period, and they're just the one's we know about. This means that we just don't know what component values are in Gilmours pedal. Years ago in the late 70's David Gilmour bought a second Big Muff as a spare and it didn't sound like the first one he already had so he had to get Phil Taylor to open it up and basically change components to something near what was in his original pedal so they would sound the same, they are that variable. Kit Rae is a huge Floyd Fan, and he's tested many Big Muffs, so to a certain degree we can say he knows what he's talking about. He's managed to whittle it down to one schematic that seems to tick more boxes than most of the others on his assessment.... This is a 1973 version 2 Rams Head Revision 3, and the basis for this build.... The schematic and PCB layout are below. This revision was a crossover of sorts between the standard version 2 Rams Head and the "Violet" Rams Head (So called because they changed the colour of the enclosure font to violet and in some cases blue in late 1973 early 1974).


KR_1973_V2_No 3 Schematic (GILMOUR).jpg     muff pcb.png


A detailed circuit layout was created by Kit Rae, which I've included below. This outlines the various stages of the circuit, and maybe goes someway to explaining how it all works together. The level of detail on kits web site is mind boggling and worth a nosy.


circuit layout.JPG


For this project I'll be building 2 identical Big Muffs, one for me, and one for my friend Chris Oliver who's a professional musician who tours around Europe and the United States with the band Chameleons Vox. He's a Gilmour fan and I offered to make him one free of charge, I'll get to present it to him at a gig hopefully later this year when they eventually decide to return to the UK.


I'm sourcing as best I can NOS parts, all carbon comp resistors, etc. There is however an issue with the 4 transistors, FS36999. There is a lot of hype about certain transistors that are more desirable in vintage Big Muffs than others. On the top of this list is the mysterious FS36999 transistor found in vintage V1 and V2 Big Muffs, which was almost certainly 2N5133 transistors with a custom mark. Modern 2N5133 transistors are not the same, and have current gains that are considered almost too low for a Big Muff, although some 1970s 2N5133 transistors measure very low too. For this build I have managed to source 8 tested NOS 2N5133 transistors with gold plated leads. These are genuine New Old Stock from the 70's never been used and guaranteed tested, I'm sure these are going to be perfect for this build, and likely the closest I'm going to get to the FS36999. They weren't cheap, but at £15 for 4 NOS transistors I thought it wasn't bad. They also look nice .



NOS 2N5133 with gold leads


The Bill of Materials for this build as per the schematic above. I'm building 2 pedals so these numbers have to be doubled. For my build i'm using 1/4 watt carbon comp resistors. Looking at the PC board, I now don't think they used 1/2 watt as they would have struggled to get them in the board in a lot of the positions. When you offer up a 1/4 watt resistor to the board the size looks correct. The diodes are an assumption as we don't know what diodes they used in the original Big Muffs. Kit Rae has suggested that 1N914 should be in the right ball park, so that's what i'm going for. Transistors with the FS36999 branding seem to be isolated to EHX products, so the belief is that they are merely 2N5133 transistors that have been re-numbered by EHX. However people think there is a certain "mojo" attached to these transistors, which is why Big Muffs with these in them go for huge amounts of money.



0.5w Carbon Composition Resistors QtyCeramic CapacitorQtyPolyester Film Capacitor QtySilicon Diodes TransistorsQtyPotsQty
2.7k1470pf20.1µf81N91442N5133 NPN Silicon3100k Linear3
560Ω10.004µf1FS36999 (Preferred)3



Boards just need etching now...... Element 14 did OK out of me this time around, luckily we have a trade account at work so I can buy anything I want from them and they just dock it out of my wages and I don't pay the tax, which is nice. Some of the resistors I had to get from the US as Element 14 wanted to import them for me from the US at a cost of £15 shipping charge..... For resistors that cost £2.50.


Luckily I sourced a supplier on the net ( that had these resistors and shipped them to me for around $3 economy shipping from the US which was much better. During my search for parts for these various projects I have noticed that there are components available in the US that aren't available here in the UK, but the killer is the shipping charge from a lot of these suppliers. West Florida Components and Small Bear are two I can think of that charge a lot to ship to the UK, Some of the Fuzz Face components I had to source from a supplier in Italy who specialises in vintage components..... We just don't don't seem to have that resource in the UK.... Anyway, that's my rant out of the way on with the build.


Here are the components ready, i just need to etch the boards now and drill them. As usual I have used the toner transfer method, and as you can probably see I had to re-touch parts of the trace with a sharpie where the track hadn't transferred properly onto the copper. I'm thinking about changing to a different method.... When I was having the issue with the power boost I was corresponding with Ian Dempsey in Australia and he recommended trying the blue Press'n'Peel transfer films. Although expensive, they are supposed to be more reliable and consistent. You can probably see by the PC board that it appears that the pots are board mounted. They were on the the original pedals, but I need to think about whether I'm going to try and do that, or just simplify the build and mount the pots to the enclosure and just wire the pots to the board in the normal way.





Part 2 will be posted soon detailing the etching, drilling and populating the board, then testing the effect in an amplifier. Finishing off with the enclosure and the decal then a proper demo in my stage rig.



Top credit goes to Kit Rae for the images and some text etc.... Not plagiarized, and hopefully it's fully understood why. A lot of them were PDF's and I couldn't link to them properly.

You can visit his excellent web site at  The Big Muff Pi Page

By now you're probably all familiar with the Power Boost pedal I built, and the issue I had with motor boating (Sky.... I'm coming for you). Well, i'm not going to dwell on that issue but I am going to post some background on the pedal, why I wanted to build it and the level of research I put in before building it. So where do i begin..... The beginning I suppose.... For those old enough to remember, cast your mind back to 1968 it was a year filled with good and bad. The Beatles released The White Album, The Kray Twins are arrested, the first Isle of Wight festival is staged, Robert Kennedy is shot in LA, Dr Martin Luther King is assassinated, and a little known electronics designer in Londons West End called Gary Hurst designs what was to become an iconic pedal used by the likes of Jeff Beck, Marc Bolan of T Rex and David Gilmour of Pink Floyd. This pedal was to form the tone of many classic songs through the late 60's and 70's. I am of course talking about the Colorsound Power Boost.


The power boost was first launched in 1968 and since then has garnered almost mythical status. For many years it was a secret weapon, that almost went under the radar of many musicians, people wanted to know how these tones and sounds were created, and a lot of musicians went on the search for this fabled effect pedal....... Their search led them to Denmark Street in London, and the home of Colorsound.... Macaris.




The 18v Power Boost was encased in a bright orange enclosure which did not go over too well in the US, so around 1971 (factory schematic dates 14.6.71) it was repackaged in a grey enclosure, changed to 9v power, and renamed the Overdriver. There was also a version made for Vox in a different enclosure (Tone Bender Mark III case) around this time, in the same grey color, but using the Power Boost name. The 18v Power Boost version was still being made up until 1972. The 9v circuits was similar to the 18v circuit, just set up to run on a lower voltage, but it also had more distortion when the drive knob was set to maximum. Both the Power Boost and Overdriver were housed in the original Tone Bender style, pressed sheet metal cases.


The circuit was possibly designed by Gary Hurst, creator of the Sola Sound Tone Benders, and many other Sola Sound/Colorsound circuits. Gary mentioned he was working on a new foot pedal with a bass and treble boost back in the January 1966 issue of Beat Instrumental, when British booster units were very popular. It was described as being a volume pedal. Gary did design a bass and treble booster housed in a volume pedal case for CBS/Arbiter, called the Power Driver, though that was much later in 1974 or 1975. Regardless of who created the original design, several improvements were made to the circuit throughout the years. Around 1996, legendary Vox engineer Dick Denney worked with Macaris on the reissue Overdriver, the last pcb he worked on before he died. The reissue incorporated a much needed volume knob into the design, which was also added to the Power Boost version. In 2008 Jake Rothman revised the Overdriver circuit to add a FET buffer at the input, supposedly improving the guitars tone control interaction with the circuit, and the same was done to the Power Boost in 2004. Other revisions have been made, including changing the drive pot to anti-log, giving a wider gain spread, and adding an AC adaptor jack and power LED. As of 2013 Macaris also sold a very accurate replica of their original 18v Power Boost, built by Stu Casteldine


The original Power boost ran on 2 9v batteries, therefore 18v, it has 3 controls Bass, Treble and Volume (Which isn't really a volume but we'll come onto that later on) To understand how this pedal works you need to hear it, here are a couple of examples of the Power Boost pedal being used to the max. The first clip, is of the 3rd guitar solo from the song Dogs by Pink Floyd, from their album Animals.. This is pure Power Boost and nothing else, with just a touch of slap back echo. You can hear that when played high, the boost sounds clean, but when he plays the lower notes there's a hint of distortion. This solo was likely recorded very loud in the studio, with the boost pedal probably set at about 60% on the volume control.....



The second clip is the classic song Comfortably Numb, this was filmed at Earls Court in 1980 on the Wall tour. Not the best quality in the world but at 5.00 minutes in you get the solo which again is power boost, but also a fuzz pedal call a Big Muff. (I'll be making 2 Big Muffs later). David Gilmour always uses a Power boost and Muff together.... They seem to work really well together.



The 9v Overdriver as stated above was designed for the US market initially as it was thought that the bright orange colour and 60's type lettering wouldn't go down well. they changed some component values, reduced the voltage to 9v and in effect created an overdrive pedal which is very different to the power boost.


Many times I've seen on various forums etc on the web that the Power Boost is the same as the Overdriver.... In my mind they're not. The only similarity is the circuit. The Overdriver lacks the head room that the power boost has and therefore falls into a dirty overdrive sound a lot earlier on the volume control than the power boost does. The Overdriver hits dirt at about 30% on the volume, where the 18v power boost doesn't get to overdrive until the volume is at about 70% on the volume. this means that the power boost can be used more as a clean volume boost, and also EQ before it goes into overdrive. It's for this reason I feel that the "Volume" control on the Power Boost should really be labelled Gain, and not Volume, as even on the lowest volume setting it boosts the volume by around 15db.


Now, onto the circuit, there are 3 schematics for this pedal, the first 2 are 18v circuits, the last one is a 9v circuit that was designed for the American market, the name was also changed to the Overdriver for the 9v version. The version I decided to make was the first early version. I distinguish the first 2 versions by the inclusion on the first version of a 10k resistor on the output. This was removed from the second version.... It's an easy way of identifying whether it's a 1st or 2nd generation pedal. There was for a very short period at the end of the 70's a 9v Power boost, but the general consensus is that these were purely 9v Overdriver circuits that were put into a batch of Power Boost enclosures, likely because they'd ran out of the Overdriver enclosures.





Being a huge Pink Floyd fan, and guitarist I'm forever trying to chase Gilmours tone, and obviously I have to have a power boost in my arsenal of effects, It's for this reason that i decided to build my own. For my build i wanted to recreate the PCB layout as close as possible, to enable me to do this i had to get as many gut shot photos as possible, thankfully there are plenty on the web, and Electric Warrior over at the DIYStompboxes forum helped by supplying photos of his own unit. Here's a photo of an original PCB. When  I designed my board I originally recreated the schematic in Eagle, and tried to get the layout to follow the same pattern as the original board.... My first eagle effort is beside the original. There's not much difference, and it all worked fine apart from the lonely ground pad at the bottom which wanted to connect somewhere it couldn't get to. That was easy to remedy on the first build manually.


vox_powerboost_005.jpg  powerboost_rev1.JPG


I built my first prototype pedal using this Eagle layout, and it worked a charm, exactly as it should. I used all brand new components, and it went together with not many issues. This first prototype was housed in a plain aluminium enclosure and was sold on to a friend on my Facebook at cost price. I still needed to build my own Power boost, but wasn't happy with the board layout.... I wanted it to look more like the original, so for this I employed the use of Microsoft Paint


Yes, I loaded the image into paint and manually altered the Eagle layout to look like the original...... And this was the end result.




Following the completed design of my board layout, I had to etch it... For this I utilised the toner transfer method. I printed a mirror image of the layout onto some glossy photographic printer paper, and then basically ironed it onto the PC board blank. Once the board was etched, i populated it with NOS "Iskra" resistors, Mullard "Tropical Fish" capacitors, and new Vishay polarised capacitors. I also used the same transistors as the original, BC184L.... The end result was the board below


20622307_10155700899034783_2724694703810435117_n.jpg?oh=289a0db05e873a09434c41e86f6741bf&oe=5A1A55B1  20106809_10155628964594783_1906511156337230422_n.jpg?oh=ce6fed949dec33387999cbfc45df3a8c&oe=5A26F2BB


I then got my designers hat on and plagiarised the internet and created my own decal for the enclosure......... Of course I had to use an orange enclosure, and I just loooooove 60's font. I have used the Colorsound name, but of course If I built one of these for someone else, i wouldn't as it's copyrighted, and a trade mark of Macaris. The decal is a water slide decal that I printed on from my ink jet printer. After I printed it, I then lightly sprayed some varnish onto it to prevent the ink from running when i put it in the water. Applied it to the enclosure, and then sealed it with about 5 coats of varnish. now all that's left is to test it........ video to follow.





A short'ish demo video showing what this pedal does and how it sounds



Thanks to Electric Warrior for helping me with photos etc when i was planning the build.

Some text has been lifted from Kit Rae's excellent web site at Guitars and Gear  this is probably the best resource on the net for Big Muff & Pink Floyd related equipment info.

Following on from my first haphazard foray into pedal building with the Colorsound Power boost fiasco, I can safely say that it was frustrating, educational and entertaining in equal measures. To this end I've decided to start blog posts detailing my various adventures, and misadventures in boutique pedal building.


Ahhh.. boutique pedal building. A licence to print money really, and all you get is a pedal that is a copy of an old 70's design, maybe with a few enhancements. Take for example the Power Boost that you're all familiar with by now. Total cost of that pedal to build was around £25 all in. that's the enclosure, the components and the PC board blank. To buy that exact same pedal in Macaris in London is a whopping £259!!!


I've probably not told you much about myself up to now, so here is a potted history. I've been playing the guitar since I was 13, semi pro since I was 18, turned pro at 22. Worked at various studios in and around London, did sessions, etc etc. Got out of the pro business when I met my wife, now i'm in Engineering as a Quality Assurance Manager for a motor sport company. my favourite guitarist is David Gilmour, and i'm currently working towards starting or joining a Pink Floyd tribute band.


My interest in electronics started last year when I decided that I couldn't afford to buy the pedals that I wanted.... So I decided to build them myself, however getting into electronics theory I've found to be a steep learning curve, but enjoyable. The Colorsound Power Boost was a labour of love for me as I wanted to create the pedal as accurately as possible to an original. Therefore the amount of research I did was probably over the top, collecting as many gut shot photo's of the pedal as possible, and copying the PCB as accurately as possible. I think i ended up with something that is for all intents and purposes a real functioning Power Boost the same as they had back in the day (Minus the Sky TV issue...... Obviously they didn't have Sky Q back in 1969)


So on with this blog post and without further ado my latest build. This is to be an exact copy of the Arbiter Fuzz Face pedal, this pedal is as simple as it gets with just four resistors three capacitors two potentiometers and two transistors. That's it! This was used by pretty much everyone in the late 60's and onward like Jimi Hendrix including David Gilmour (there's a pattern there isn't there) The first Fuzz Face came out in about 1966 and was powered by a single 9v battery with 2 matched germanium transistors, there were at least three types used NKT275 AC128 and SFT363E. All of which are fairly hard to come by nowadays. The original germanium Fuzz Face has a warm fuzzy distortion that is easy to tame. As time wore on Germanium transistors were slowly being phased out in favour of the more stable and consistent Silicon versions, as a result Dallas-Arbiter began equipping the Fuzz Face pedals with these new transistors from 1968 onward with differing results. They do sound different from the original Germanium versions usually with a more harsh and aggressive clipping as opposed to the "soft" clipping characteristics of Germanium. The silicon transistors that were used in these versions included  BC108CBC108C BC183L BC109  BC109CBC109C and BC209C.


Original germanium pedals are now highly sought after, and regularly change hands for anything upward of £1000!!! Just for four resistors, three capacitors, two potentiometers, and two transistors... Where's the logic in that? The silicon ones are obviously cheaper, at around £700!! Even the new reissues are over £120, which I think is criminal for what's in it... obviously you're paying for the name. Especially when they call one model the "Jimi Hendrix Fuzz Face" obviously that's going to cost more at around £170..... What's the old saying? Money for old rope...... repackage, and hike the price up, just don't change the innards. I won't be paying that.... This build is costing me around £20 all in, that's the enclosure, and the period correct parts which are slightly more expensive than modern equivalents. The rest is just my time, and enjoyment at creating something i can say "I did that".... And "guess what, it sounds just like that £700 original"


For this project i'm looking at recreating David Gilmours guitar tones from the early 70's to around 1975, during this time he used a silicon fuzz Face which can be heard on the guitar solos during this period, notably on the album Dark Side of The Moon where he used it extensively on the solos to the songs Money and Time. He also used it at Pink Floyds famous audience-less concert in the Roman Amphitheatre in Pompeii in 1971..... Here's a brief clip of David Gilmour showing how this brilliantly simple circuit sounds when built into a pedal



here is the schematic and PCB layout that I'll be using for the build


Silicon Fuzz Face Schematic


PCB layout


Here is a photo of an original silicon Fuzz Face PCB


Original Silicon PCB


The PCB layout above which i'm using for this build is actually the issue 1 layout for the germanium Fuzz Face which was positive ground, therefore I'll have to remember to change a few components to ensure they work in a negative ground build. Notably the 2 polarised capacitors the 20uf and the 2.2uf will need to be turned around or it won't work. the transistors i'm going for are BC183L in Q1 and a BC183LC in Q2. This is a recommendation as they're exactly the same as what are in Eric Johnsons Fuzz Face, also the  hfe of each transistor has been matched to be the same as Erics fuzz Face.



so, here is my etched board ready populated.... you can see I had to twist the legs of the transistors slightly as the pin outs are different for this board. I've also used period correct parts, not that they sound any different from modern components but they just look "right", and as usual for my own builds I'll try and keep the components as authentic as possible. Hence the carbon comp resistors, and the flat polyester cap. The only brand new part is the 22uf polarised cap, that's a modern Vishay cap I had left from the Power Boost build. The 2.2uf cap is a NOS philips.


Fuzz Face board


Component side


You'll notice that comparing the photos of my board and the original some of the components are in a different place. When I populated my board I followed the schematic and not the photo, transistor Q2 (The bottom one in the photos) is in a different position on this board to the original. I can only assume that in 1968 when they first brought out the silicon versions of this pedal they changed the board layout to compensate for the changes etc. however, nowadays it's standard practice in the pedal building fraternity to use the same board for both and just make the adjustments with components placement and orientation during soldering. Also I'm using a 22uf capacitor instead of a 20uf... This is purely down to availability, I also don't think it'll make much difference to the end result as I've seen Fuzz Faces with 22uf caps in as well as 20uf. I also had 22uf caps left over from the Power Boost builds.


The wiring diagram for the various parts of the PCB are as shown in this diagram here.... Obviously I'll be using the NPN Silicon diagram on the right. Here you can also see that my component placement is as shown in this diagram. (This diagram was supplied to me by the guy that created the PCB layout... PigeonFX)


Wiring Diagram for Fuzz Face


Now I just need to wire it and test it.... I'll do that during the course of today, and post the results later.


UPDATE - 08/28/17


I have wired the pedal, and will post a short demo of it soon. I've decided to show a proper demo so you can see how this thing interacts with the guitar, the only way I can do that is to film the demo hand free, in other words so i can play the guitar properly as opposed to holding my phone in one hand, and just making noises on the guitar with the other. not very good and sounds awful. i've therefore ordered a cheap tripod adaptor for my phone so I can mount the phone on my camera tripod and film properly.


This pedal is awesome, and sounds just like the video above, (although the video above of David Gilmour does have a small amount of echo on it)


I did have one issue with the build however and that was after wiring it, i had no sound..... not a peep, so triple checked the wiring to ensure it was correct, and also rechecked the placement of the components. I then got my multimeter, and started checking continuity across the board. that's when I saw this............ A small break in the track for the positive battery lead. i simply re-soldered a bridge across from the pad to the track and it burst into life. i'll post the video in a few days once the tripod adaptor has arrived.