Friday, November 30, 2012

Bending your Tone for Page

The Led Bender mkII
The UK fuzz mania began in 1965 probably after the Rolling Stones recorded the 3 fuzz notes that changed the history of rock'n roll: the opening notes for their hit "Satisfaction". First recorded on Brian Jones' Harmonica in Chicago and 2 days later by Richards using a Maestro Fuzz Tone, the opening notes were meant to be replaced with a horn section later on, but luckily producer Andrew Oldham decided to keep it as it was. The song was an immediate hit across both sides of the Atlantic and fuzz was the talk of the day. Guitar legend Vic Flick, the man begind the James Bond Theme, brought the American Fuzz-tone (FZ-1) to the UK and asked electronics engineer Gary Stewart Hurst if he could modify the unit to increase the tone sustain. Hurst used a similar 3 transistors architecture and designed the first Tone Bender, referred today as the mkI. Within a year or so a plethora of fuzz pedals were issued by various brands like the Arbiter Fuzz Face and the Baldwin Burns Buzzaround. While the Fuzz Face became the most famous fuzz of them all, the Tone Bender was probably the highest selling unit ever due to the fact that it was issued under various brands like Sola Sound, Vox, Rotosound and Marshall. The MKI version was made famous by the Beatles (Rubber Soul), Mick Ronson (Ziggy's Spiders from Mars), Pete Townsend and Jeff Beck.

Jimmy Pages' Bender original receipt (left) and the Sola Sound reissue of the mkII (right)

Despite its legendary sound, the Tone Bender mkI's sound and design was not flawless. Circuit was sensitive to gain tolerances of the transistors and the sound was buzzier than some wanted. A new 2 transistor design was issued by Sola Sound and is referred to as mk1.5. This design could probably be the original 2 transistor design which Arbiter issued during 1966 as the Fuzz Face. The circuit was more stable, the sound was richer and saturation was not too heavy. The huge success of the Fuzz Face drove the competition further and Sola Sound made the leap to a 3 transistor architecture but this time it was a first amplification stage driving a Fuzz Face style 2 tranny stage with Germanium OC75 or OC81D were used on all 3. Different brands featured similar mkII design using various transistors, and they all were successful throughout the late 60's and 70's. When referring to legends like Jimmy Page and his tone on the Led Zeppelin I and II albums from 1969 the Tone Bender mkII is considered to be a major factor.

The Led Bender mkII
Even more variant and diverse than the Tone Bender mkII of the Fuzz Faces is the Tone Bender mkIII which was issued 1968 and sparked a whole different era of fuzz pedals which led to the birth of the Big Muff.

After building more then a few fuzz pedals I decided to get into the Tone Bender jungle. I realized that I really wanted the mkI and the mkII, but the mkI seemed tricky and risky so I took the mkII path. Now Germanium trannys are always expensive and I found some silicon versions which got good reviews so I decided to give it a go.

After many unsuccessful attempts on various schematics I found one which worked, sounded good and by replacing trannys I really managed to get that bendery tone I was aiming for: Raw, punchy and versatile. Once you go for the Whole Lotta Love riff with humbuckers or How Many More Times with a Tele, you'll know this is the one.

I started with the GGG NPN design modded by J. Orman and B. Trembley which is a good choice. You can find the schematic here, but I really wanted to have the extra Tone control so I went the Hot Silicon path  designed by Gus Smalley. The schematic is shown here. The two designs are quite alike and sound more or less the same depending on the transistors used. I took Mictester's and JD Sleep's advise of putting low gain sets and went to buy the 2N2369 parts instead of BC109C or 2N5088. I ended up using 2N2369 for Q1, 2N3904 for Q2, BC109C for Q3 and 2N2369 for Q4 for the TONE stage. I also liked the FAT switch which switches between low and high values of the input cap. Once I got that Jimmy Page sound I called it a day and painted the new Led Bender in a Zeppelin homage style.
Gut shot of the Led Bender. VR1 is a pot on the right side.
Might as well change it to a  board resistor.

I am sure this is not the end of my Tone Bender phase but it sure sounds great, I am getting a friend to lend me his Sola Sound reissue of the mkII professional and I'll compare the two. Meanwhile I play Good Times Bad Times using this little baby connected to the Runoffgroove Supro amp emulation pedal and with the right  reverb I can nail that super tone. A major milestone in my Fuzz quest.

Thursday, November 15, 2012

The Flying Rat

The 60's and early 70's were all about driving tube amps into overdrive heaven and on the way use fuzz and treble boosters to get the job done. Most Fuzz stompboxes were, in fact, so effective that you didn't really need the amps to be that heavily driven anymore, but they killed most of the guitar's tone and dynamics. They took over the sound (Fuzz faces and Big Muffs to name a few). 

As people got fed up with fuzzes and wanted back that dynamic distorted overdrive, Orange amde the first step and came out with their Overdrive amp in the mid 70's. That started the distortion race all over again. The idea of a stompbox giving you that distortion, which was so important for rock guitarists, yielded the next step in the second half of the 70's. In 1976 Amlyn Crowther designed the Hotcake which would become the first boutique overdrive (Sonic Youth, Pavement, Radiohead, Protishead and many other consider it their "secret weapon'). Japanese based Ibanez and Boss came out with the classic Tube Screamer and the OD-1 (DS-1 too), respectively, around 1978. In Kalamazoo, Michigan, two guys in a basement started selling custom ordered pedals under the Pro-Co name. Those were the first Rats. All the above brands produced pedals based around an operational amplifier and have some similarities in their designs. All three became classics and over the years got reissues, sequels and modified versions. 

I decided to build the Rat for 3 main reasons: a) It is a classic pedal and deserves FuzzQuest attention. b) Some of my favorite guitarists use it or have used it over the years. C) There is no real mojo in this circuit. the LM308 chip and clipping diodes are all pretty straightforward. No Germanium PNP or de-gooped old boxes with debates over them. The amount of schematics on the web is infinite and the mods are all given out. You can build the circuit with mods and it will sound just like the real thing. Even better. Guitarists who used this unit and made it famous were Thom Yorke, Thurston Moore, Stephen Malkmus, Bernard Butler, Marc Ribot, Bill Frisell, Frank Black, Jeff Beck, Andy Summers, Graham Coxon and Kurt Cobain, to name a few. If you told me only Thurston and Ribot were on this list, it would have been enough for me. This might have been the overdrive/distortion used by Ribot on Rain Dogs by Tom Waits. Imagine that!

The Multi Rat Schematic
So, I gathered about a dozen schematics I considered to be trustworthy. RG Keen and Jack Orman did some tremendous work given on the aron nelson archive and diystompboxes. You can download the schematic shown here, but Beavisaudio, GGGSabrotoneSoulSonic, Gaussmarkov and others, all have verified circuits readily available, just click the links.

I added the Ruetz mod to conttroll the highs and called it EDGE. Got an On/Off/On switch for choosing between the diodes, MOSFET clipping and clean boost and named it CHARACTER. DISTORTION  FILTER and VOLUME are similar to the original. Apart from that it's a vintage Rat clone.  The added mods give it a lot of "elevation" so I called it the BAT. Also I liked the Mokafix Bat VST emulation and adopted the name. It really is a mouse with wings.

So I got the circuit working and painted the enclosure. I really dig the sound which sounds pretty awesome especially with my English Channel emulation of the AC30. I completely understand why this became a classic unit. This is the distortion we grew up on listening to grunge, alternative and punk rock from the 80's and 90's. Great sound, versatile, easy to use. Humbuckers with an AC30 you get the British indie rock of Suede and Blur. Single Coils with Fender amps will give you Sonic Youth and Pavement flavors. Pretty Amazing. With the clean boost mod you can get great fuzzy overdrive and you can drive other pedals on the chain or drive your amp further. Super!  

As always, if you want audio demos you have to comment and ask for it. I hope to get some clips done for all my posts but it's gonna take a while since I am on a building mania and even posting on the FuzzQuest blog takes me forever.

Anyway, a very recommended build. Pretty easy and fun with a lot of options. With the Ruetz mod attenuating the highs and the clean Boost which is not so clean I got some wicked fuzz sounds. If you are wondering, you can be sure that a Tube Screamer clone is on the way. Naturally.

Saturday, November 10, 2012

The Pink Face

The Pink Face
Throughout the history of fuzz pedals, fuzz guitarists and psychedelic fuzzy solos, there is no fuzz which has received greater attention than the legendary Fuzz Face. Originally produced by Arbiter Electronics in England and appeared during 1966 the unit was an immediate success. Many of the greatest guitarists in rock history played their best solos and riffs through a Fuzz Face including Hendrix, Gilmour, Blackmore, Harrison, Townsend and many more. Nevertheless, the dependency of the Germanium transistors on temperature resulted in a lack of tone consistency and many players suffered on stage from this effect. To circumvent this issue Dallas Arbiter started issuing Silicon versions of the FF somewhere around 1969 replacing the NKT275 trannies with BC108. Silicon was the new hype at the time and it seemed that by 1970-71 everybody was switching to Silicon faces. Hendrix's Band of Gypsys, Gilmour on all PF albums and tours since 1971 including all of the solos on Meddle and Dark side of the Moon are probably the most documented examples. One of my favorite guitarists Michael Karoli (Can) also used Silicon Fuzz Faces to create his raw and untamed distortion throughout the history of Can, so this was enough to get me going. 

Both designs are pretty close with the Germs being mostly PNP and the Silis being NPN. Comparing the sound of the Germanium units with the Silicon ones it is often said that while the Germs sound raspy, warm and sweet, the Silicons are brighter, edgy and have more gain. Well....from my builds....this statement is....TRUE!

The original 1966 Arbiter Face - Germanium
On my Fuzz quest I really couldn't imagine the journey without understanding the differences between the two FF versions and there was no other way than building the two. After I finished the Germanium Fulltone version I started to drown with info on the Silicon versions: Fulltone, Analog Man, Dunlop, Runoffgroove, GGG you name it. I looked through dozens of schematics and breadboarded some of them. I even looked at the German Schaller Fuzz (FF variant) after reading that Michael Karoli (CAN) used one. Actually, the first fuzz I ever built was the Runoffgroove SiliFace II and I loved it for some months. That was what got me interested in fuzz pedals in the first place, My Fuzz quest started because one fuzz was not enough to get the range of buzz tones I was after.

The 1970 Dallas Arbiter Fuzz Face - Silicon
Due to the fact that the Fuzz Face design is tolerant to part values many versions have been issued over the years and the amount of Fuzz Face versions became quite vast (just like it happened with the Big Muffs or the Tube Screamers). The design is so simple that small part changes resulted in some sonical change. After all the entire unit incorporates 4 resistors, 3 caps, 2 transistors, 2 pots and 1 switch. That's it!

4 resistors, 3 capacitors, 2 transistors, 2 potentiometers
The sound I was aiming for was that of Gilmour playing the Time solo on the album version of the Dark Side. I started out with the GGG early 70's Boutique NPN Fuzz Face after my success with the GGG 60's version. I liked the PRE GAIN knob and the circuit seemed pretty good, but something was missing. I didn't box the circuit and it stayed on the shelf for some time. I built a few other Fuzz pedals and when I thought I understood more about what I wanted I revisited the circuit. This time I modified the circuit based on the Axis Face version by Phillip Bryant modified by Brett Robinson. 

Gilmour's early 70's rig

I did a lot of testing using Hi-Watt amp emulations, tweaked many of the parts in this little circuit, changed trannies and used several guitars. Surprisingly, I ended up using 2N2369 (hfe=70-90) for Q1 and BC109 for Q2 (hfe=200). The BC108C I had (hfe around 400-550) seemed to be too pumped up for my taste. I settled on a 50kA pot for the PRE GAIN and a 100kA for the VOLUME. 220n cap for the input and 30p cap on the bridge for lo-pass filtering. I replaced the CONTOUR pot with a 470R resistor and kept the 22uF Fuzz cap. I kept the reverse polarity protection and cut off the strange feedback diode bridge which didn't seem to affect the sound. Biasing Q2 I got 4.5V with resistance being about 3k3 so that's about 4k3 total Q2 bias. It's funny that this fuzz is currently my most tweaked fuzz circuit to date. Only a few parts but so much experimentation. Other fuzz circuits you get the schematic, the parts, breadboard and maybe test a few transistors, bias them and that's it. Along with the early Tone Benders and the Maestro Fuzz Tone which are more complex it's one of the toughest, considering its architecture.

Luckily, somebody at work who knows I am always on the lookout for metallic enclosures, gave me this great candy box. I couldn't have asked for a better design with those pink pigs on a round enclosure making it suitable for a Fuzz Face and for a Pink Floyd related sound, so I jigsawed it to the right height, called it Pink Face, mixed my glass paint bottles and came up with a magical pinkish tone... Perfect!

The sound is well worth the effort. It's not as warm or sweet as the Germanium version but it does give you the Time solo style. Bright when the FUZZ pot reaches max. The PRE-GAIN gets you that rolled off effect for cool rhythm chords and sparkly clean chops. Using a treble booster in front enables you to get great tones with the FUZZ knob below max. I also tested it with a Wah in front and no buffer was needed. Definitely a must build on my fuzz journey towards a better future.

If you want to learn more about the the topology of the fuzz face there is no better place than R.G. Keen's article: The Technology of the Fuzz Face. It helped me a lot in choosing the right part values and testing transistors both in my Germanium unit and this recent Silicon unit. It is really the Fuzz Face Bible, highly recommended and insightful. 

The schematic I drew up in Chrome Circuit Lab is shown here for reference but feel free to use it, tweak it or twist it. I will update it if I decide to change it. The feedback diode did not really do anything so I left it as in the Fulltone version.

Hope you get to enjoy it! You can also have a blast using Mark's vero layout on Tagboardeffects.blogspot,com

There is a lot of Fuzz Face info all over the web, here are some more recommended pages for extended reading on this matter: