Britannia - The new British Channel by Runoffgroove

In 2004 the Runoffgroove team released their famous "English Channel" pedal version for the VOX AC30 Top Boost amplifier. Their acclaimed JFET take on the tube overdrive sound was a big part of the amp-in-a-pedal mania that soon flooded the guitar world with boutique vendors releasing pedal versions of every amp known to man. What started as a unique way to generate the tube gain stage using silicon transistors was slowly replaced by new techniques which replicated the tube sound better but was not necessarily based on the original amp schematics. Using the new technique, Runoffgroove updated their schematics starting with the fabulous "Azabache" circuit to replace the "Professor Tweed" as the Fender style circuit. "Britannia" is their new approach to achieving the famous sound of the VOX AC30 Top Boost. The "English Channel" was a very good overdrive in my opinion. I built it in 2011 and I was quite happy with the results. I even compared it several times with a software version of the amp and I was always satisfied.

When the "Azabache"came out, I built it right away ("Tweed Palette" on this blog). Immediately it was obvious that the ROG team has made great progress in understanding the overdrive character of the tube amp, so it was no surprise that when they released Britannia, it instantly reached the top of my list.

I decided to go with the 1776 Effects PCB this time just to check out this path as I usually build the circuits on pref-board or vero. I was really pleased with the PCB because it was built so well, with so many small features to ease the work of the builder. I highly recommend these PCB layouts for everyone who is interested in building his pedals faster and safer. The features I really liked about the PCB:

Clear and logical layout.

Clear printing for each part, including pots, trimmers, grounds in/out and 9V supply.

Tips on the drain voltage for each transistor with the voltage values printed next to the biasing trimmers.

Location for soldering test points.

Great value

So, back to the VOX AC30 Top Boost story (from wikipedia):

"The Vox AC30 was originally introduced in 1958 as “big brother” for the 15W AC15 model at Hank Marvin's (The Shadows) request because the AC15 was not loud enough with the screaming fans at Cliff Richard's concerts. Vox's original flagship amplifier. The Original first generation AC30, or AC30/4, had only a single 12" Goodman's 60W speaker in a "TV Front" cabinet, as opposed to the later, conventional twin 12" speaker configuration. The AC30/4 sported two channels with two inputs – hence the “4” in the model name. The amplifier used a GZ34 tube rectifier, three ECC83s (12AX7) for the Normal channel and it had EL34 tubes in the power amplifier circuit.

In 1961 the "Top Boost" (or "Brilliance") feature became available as Vox's optional addition of a circuit that introduced an extra gain stage and tone controls for bass and treble (as opposed to the single "tone" control of earlier AC30s). The unit became so popular that its features were soon incorporated in newer AC30/6 models, and the controls moved from the rear panel to the control panel.

The classic VOX AC30 Top Boost

Vox AC30/6 amplifiers from around 1963 had already implemented the top boost, and therefore had 3 tone controls. People began to refer to these amplifiers as AC30TBs. In addition to the "Normal" version without the Top Boost, and the Top Boost version (which was a Normal version with the "Brilliance" unit added), Vox, with slight circuit modifications, created two more versions that were “voiced” in Brilliant (Treble), and Bass styles. Of all the different models that came around many consider the AC30 "Super Twin" to be the ultimate AC30, with a "trapezoid" shaped head and separate speaker mounted on a trolly."

Brian May and his VOX wall of AC30 amps

Those early 60's TB models became the tone of choice for many legendary musicians and bands. To name just a few, we are talking about The Beatles, The Byrds, Hank Marvin (The Shadows), Brian May (Queen), Vic Flick (James Bond theme), Rory Gallagher, Tom Petty, Noel Gallagher (Oasis), Johnny Greenwood and Thom York (Radiohead), The Cure, The smiths, Muse, R.E.M and almost every band who wanted that sweet British crunch. Vox was quite an amazing music company which developed many solutions for musicians and had VOX organs, VOX wah pedals, Vox guitars, VOX PA systems and each one of those lines became a legend of its own.

More info can be found on the VOX website: http://www.voxamps.com/history/

Inside the original VOX AC30

The front panel and tubes of the AC30

All I can say is that this amp-in-a-box completely blew me away and it rocks soft and hard at the same time. I love the range of the GAIN pot which really goes from completely clean to jangly crunch to ooomph power drive. The TONE controls are BASS and TREBLE which are super effective. With high GAIN settings and high BASS you can really rock hard a la Brian May, while low BASS gets and mid GAIN gets you to Rory Gallagher territory. Guitar volume is effective too. Putting a Treble Boost in front or a fuzz will give you ultra tonal flexibility. An additional overdrive on wither side will be super cool also. The coolest sound I got so far was with my Tele in neck pickup, volume knob on the guitar backed off a little and GAIN at noon. What a sweet smack in the face. I used my former ENGLISH CHANNEL enclosure and changed the knobs so the pedal looks quite similar, but underneath the hood it's a whole new beast.

All this magic in a small PCB - The Britannia on the "1776 Effects" PCB 

And the amazing pedal in a unique enclosure which used to house my English Channel

The Runoffgroove page with all necessary info is found here:

http://www.runoffgroove.com/britannia.html

The 1776 Effects website:

http://1776effects.com/

Below is a long demo of the pedal with my MIM Telecaster through a Dr. Z MAZ 18 cabinet.

Just listen to the vast amount of sounds obtained by tweaking the guitar's volume knob, the GAIN level and the TONE controls. Just dime that GAIN knob and start those Tom Petty chords or those open arpeggios. Add a fuzz in front and you are in 60's heaven. 

ROG Britannia demo - Telecaster-Britannia-Dr. Z MAZ18 by Doron Barness on Mixcloud

Don't miss out this great pedal. It quickly became on my top 5 all-time overdrive/tone pedals.

Ginger Bread Bass. Hot from the oven

It has has been a while since I revamped my bass sound palette. I have been using bass fuzzes, distortions and filters of all kinds and I was pretty satisfied. I love the RAT clone on bass giving me the Kim Gordon, Sonic Youth style. I love the Mu-Tron III or the Tri-Vibe (Uni-Vibe) on bass for some really wacked synthy filtering sounds, and I always sleep well after a night out with a Big Muff, Germanium Fuzz Face or Fuzzrite for killer chain-saw bass riffs. One thing I never got was that sweet overdrive of those old Ampeg amps. Even the Runoffgroove Flipster was not a constant lodger on my rig since I was just not using it enough although it sounded pretty strong and biting. When Runoffgroove came out with the Ginger circuit and stated that it was an improvement over the Flipster, I couldn't resist and it has been sitting on my wish list for over a year.

The original 1965-1971 Ampeg SB-12 Portaflex.
A 12" recording work horse.

Well I finished it and ordered the most beautiful ginger-sparkly-rust enclosure on Mammoth Electronics. When I first played it I knew that it will most definitely replace the Flipster on the bass rig and that just maybe I found that 60's bass sound I love so much. Moreover, what really stunned me was the great overdrive sound it gave me on my electric guitar with humbuckers. Wow, if you want to drive your guitar with some heavy bass fuzz riffs, this unit can really complement a good fuzz for ultra pumping riffs.

The Project itself was not difficult and the noise was not enough to go and replace the trimmers with fixed resistors once you bias the 2N5457 Q1 and Q2. In fact, I always socket my trannies so that I can replace them or test a few before settling down. I did have to troubleshoot a bit. On the first attempt to bias Q1 I realized that the trimmer does not change the drain voltage at all. I found out the circuit ground was not connected. What a shame. Then I saw it still didn't work after I connected the ground. Found out another connection was not properly soldered or was it a cold soldering case? I don't know but once the little troubleshooting was done I was in bass heaven for about an hour until I realized it was 2 in the morning.

This build certainly got me going berserk on my bass all over again and that's what I like about it. I don't have a fender P-bass or a J-bass but I am convinced that this pedal sounds even better on fender basses than it does on my Music-Man style bass.

Ginger bass by Runoffgroove by Doron Barness on Mixcloud

The schematic, and pref-board layout which I love so much from Runoffgroove can be found here. It's too bad the guys over there at Runoffgroove have stopped publishing layouts. I really dig their designs and so does anyone I know. I just might print a T-shirt with a "holler" to bring them back to earth.

  

A Palette of Tweeds - ROG's Azabache

Well, I'm really excited about posting today because I think one of my missions throughout this quest is over. A large part of my FuzzQuest has been devoted not to fuzz pedals but to amps or amp pedals which complement fuzz pedals. Over the past few years I have built the Thor (Marshall emulation), The English Channel (Vox) and the Professor Tweed (Fender), all Runoffgroove designs. I built other amp-pedals but I consider Vox, Marshall and Fender to be the most defining amps in fuzz history. Anyway they are all good pedals but there was something about the Tweed pedal which didn't sound right to me. It was good but I didn't get that Neil Young sound or Keith Richards sound which I really love. It was a good pedal for a fuzz kicking it, but as an overdrive it wasn't that rewarding.

So I started looking for more schematics and found that Wampler, BJFE and Catalinbread had some wicked stuff and I really wanted to give one of them a go. Just as I set out to, Runoffgroove came out with a very interesting design of a new Fender-like design which sounded good on paper. They called it Azabache. Surprising enough I also found a really nice guy who sent me the PCB for 10$ so I got the parts I needed and started to work. Usually I like building my own prefboards or tagboards but this time I thought "why not?"

The Azabache populated PCB 

The drilled enclosure almost ready

All sitting nice and comfy 

Ready for lock down

I love this combination of colors

I have played around with this pedal both in rehearsals and on stage and it always kicks ass. It is so versatile that it can go from muddy bluesy 50's style tweed to bright Black or Silver face country clean style. It's got warm overdrive that is to die for and with my telecaster it's just unbeatable. the SCOOP and BRIGHT switches are subtle but they do exactly as described and mixing with them on top of the TONE and GAIN knobs produce an endless amount of tones. I was so impressed by the range of colors it had that I named it Tweed Palette. Took me a while to decide on that name but...there it is.

This thing was not a kit. I just ordered the PCB and all the parts besides that were ordered separately. Just because someone asked I am mentioning this again:Q1 was 2N5457, Q2-4 were J201 and Q5 was 2N5088.

A mod from the RUnoffgroove team on DIY Stompboxes for reducing the trebleness of the pedal: Substitute the 47K resistor going to TONE 1 for a link (or a smaller value resistor).

I did some playing around with a tele and a cabinet simulator and sent it over the ROG guys with many thanks:

Now you probably want to know how it sounds with a fuzz. Well, with a silicon fuzz face like my Pink Face it sounds the best. Instant 60's fuzz. Did I say that half of my quest is over?

Anyway here is the ROG Azabache project and schematics. I would love to know how it stands next to the Catalinbread Formula No.5.

Driving Down Da Bass

The Caribass - ROG Flipster

This time we are off and away from the world of guitar and into the bass we dive deep.

Runoffgroove's (ROG) Flipster was designed to emulate the tone and drive of the famous Ampeg Portaflex SB-12 bass amp. This amp was the little brother in a series of tube amps designed in the mid 60's. The amp had a 12'' Jenson speaker cabinet and was probably used on many recordings from 1965 and on through the 70's. Mo-Town Bass sound was known for using Ampeg bass amps.

I don't know too much about bass amps but I do know that I like Ampeg bass amps. They are smooth and have a lot of bottom as well as edge. I particularly love controlling the character of a song using bass, whether it's deep dub style lo-pass or grungy-rock overdriven tone. When I play bass I sometimes like to switch quickly between styles and all that flexibility means I need a good pedal, capable of drive range from clean to hard drive with some equalizing options.

A 1965 Portaflex SB-12

Assuming ROG designs are always good, especially for emulating tube amps, and this one had 2 12AX7, 2 7868 and 1 5AR4 tubes. I built it and tried various FETs to get the gain I wanted. Funny thing, I made a nice error hooking up the the TONE knobs and got 2 modes for the tone-stack. ROCK mode for a more edgy-punchy curve and a DUB mode with less treble and more lows.

I played with the pedal on more than a few occasions and I still use it more for live than in the studio. It gives you the ability to drive your bass without touching the amp and it's not like an overdrive pedal which cuts the lows. You can maintain your lows and still bark and bite. For really hard bass distortion there is nothing better then the Pro-co Rat or any version of it like my Bat shown here on a previous post.

There is a new Portaflex SB-12 version now called "Ginger" which is supposed to be better. I think I know what they are talking about, The Flipster was good, but not so much as an emulation of the Ampeg amp. I did have problems getting low gain clean tones with the Flipster but it was good for what I needed.

Because I got an interesting paint job on the wooden enclosure which had some Carribean touch to it I decided to call the pedal Caribass. With my Music-Man Sting Ray replica bass I can get some great tones with almost any style.

I am definitely getting ready to upgrade the Flipster to the Ginger. Stay tuned as it is right around the corner.

If you want gut shots or audio clips just comment and I'll add them. As always, schematic is available here. More info from Runoffgroove can be found here.

 

Tumble and Drive - the Rougue Dumble

The Runoffgroove Tumble Drive (Umble)

For those of you who are following this blog and my recent posts, it is probably clear that, although our main point of concern is the magical sounds of fuzz circuits, a great of interest is being paid to the accompanying peripherals, which have a great deal to do with the overall guitar sound. What I mean by this long phrase is that every time I think I have understood the fuzz sound of a certain pedal I am amazed to discover how different it sounds and behaves when you play with it through different amps.

That was the main reason I began building amp emulation pedals like the English Channel (emulation a VOX AC30 top boost channel) or the Thor (The Marshall 100W Superlead). You have probably noticed that when it comes to amp emulation I am very fond of the Runoffgroove design, and that is mostly because they just sound great and they definitely evoke the characteristic sounds of the amps they aim to emulate.

On of the most sought after sound of guitar amplifiers is the unique sound of the Dumble amps which have been made since the 60's in California by Alexander "Howard" Dumble. Although I have never played through a Dumble in my life, nor do I believe I will ever do, it was interesting to hear what the fuss was all about. The list of Dumble users includes some major players like Santana, SRV, John Mayer, Al Di Meola and Ben Harper and many more. Probably the most recognized user of the Dumbles is Eric Johnson who made the amps famous with his singing Fuzz Face going through an heavily overdriven Dumble.

Unlike many of the ROG designs which I built in order to get the well known classic sound of a certain amp, on this build I just wanted a good American  sound which would get me from clean to crunch with some nice lead tone and good tone control. I even asked the ROG guys about a Fender like design that would get me close to a Vibroking or a Super-Sonic sound and they recommended their Dumble-like design, called the Umble, a cascaded FET based overdrive. 

I quickly started gathering parts and had the circuit running in a few days....and YES....another great sounding overdrive by the amazing guys at ROG. This is a very versatile unit which got me playing for days getting some wicked tones. On the lower end of the DRIVE knob it's capable of some really sweet clean tones. Single coils come cleaner but with proper use of the tonestack you can get Humbuckers to sound clean too. I really love low gain pedals because I love the warm drive you can get from them. This pedal does it all, warm, punchy or razor sharp, it's all there. Once you get the DRIVE up it becomes a monster and reaches Fuzz territory towards the end. While lowering the Tone stack knobs cleans the sound, increasing them gives you more drive and half way through the dials you are already speeding on the freeway.

I called it Tumble Drive because it sounded better then Umble to me and it drives so smooth and nice.

The one thing which I really love about this design is that it also serves as an excellent booster before a second overdrive like the Supreaux Duo ("1st Page" on my blog). It sounds really good and gives you the Eric Johnson tone if you put a Fuzz Face in front of it. Actually, every fuzz I hooked up with it sounded great and so it isn't just another amp-like pedal. Although the Tone stack is a little strange to work with it sounds good: The TREBLE knob adds some BASS as you crank it, and the BASS is quite subtle.

The final thing I did just recently was adding a simple switch to bypass the first FET gain stage so that I can now get even cleaner sound on low DRIVE settings. Now it's just perfect and I really like the paint job which I got in the end with the IGNITE toggle switch.

The gain switch which bypasses the first stage gain FET (in red)

Umble with Gain switch

Again....don't pass out on this design if you are serious about american sounding overdrives. The schematic can be found here.

Below are 2 demos of my lousy playing on my ES335 clone guitar and the pedal through a soundcard and some amp with room simulations. The first is a demo with different settings and the second is a mix of 3 tracks, Riff+rhythm+solo, with various settings showing the versatile sound of the effect on a single guitar. It's quite an amazing pedal with its capabilities as a low gain overdrive, high gain overdrive, full on distortion and a great fuzz character with the BASS knob fully cranked. The tone stack have a huge effect on the sound of the pedal.

Tumble Drive - Umble on Mixcloud

Shake, Rattle and Roll - The Runoffgroove Tri-Vibe vibrato/phaser/leslie pedal

As I have stated on some previous posts, getting the best fuzz sound or for that matter getting the best sound from any guitar involves more than a few parameters: Picking style, pickups, pedals, amps, mic placement etc. All this is nice and all but sometimes there are more effects involved which really transforms the sound into something else, richer, more psychedelic, more dynamic and new. I am talking about the use of filters, reverbs, phasers, vibrato, tremolo, delay and chorus effects. The first effect I built which was not a distortion pedal was a PAiA Voltage Controlled Filter. Combining the filter with a delay pedal proved to be a super exotic source of psychedelic sounds. I knew I would some day get deeper into modulation effects. As those effects are usually tougher to build I was always intimidated to start one out.

The Swirly Vibes vibrato/phaser/leslie pedal

When I started to get deeper into the Hendrix sound I found the Univibe pedal to be something of a mysterious part of his sound. It is used heavily on Band of Gypsys - Machine Gun, and on Izabella. Later I found out that Gilmour actually used a modified version of the Univibe as the phaser on the opening track Breathe on The Dark Side album (The phaser on the Shine On riff from Wish You was an actual MXR Phase 90). The Uni-vibe was first introduced somewhere in the 60's by Shin-Ei and Vox and was intended to be used as a Leslie simulation. When ROG came out with the Tri-Vibe: a simple enough design aiming to get that sound, I thought it was a good way to get into the business. Even more interesting was the design allowing to combine two modulations together, namely pitch vibrato and phase modulation to get the rotary speaker (Leslie) effect, hence, the Tri-Vibe. I always had a soft spot for Leslie cabinets used in Hammond organs but also on Pianos (Don't Pass Me By - the Beatles), electric guitars (as used by Jethro Tull on Benefit - Guitars, vocals and flutes) and even vocals (John Lennon on Tomorrow Never Knows).

A great page for some info about the Leslie cabinet can be found on:
http://www.theatreorgans.com/hammond/faq/mystery/mystery.html

The ROG design looked very clever and interesting so I built it and stuck it in a modified tin chocolate box. After a few gigs I realized that I needed a stronger enclosure so I reboxed in a regular 1590BB Hammond style box.

ROG Tri-Vibe new enclosure

The circuit has two self explanatory knobs for INTENSITY/DEPH and RATE, and a three position switch to get the SHAKE (vibrato) in the center position, RATTLE (phaser) and ROLL (rotary speaker). I love the rate knob which gives you a wide frequency range from about 0.2 Hz up to 7 Hz or so, that's a few seconds a round to a few rounds a second. Both vibrato and phaser are smooth and gentle and sound pretty damn good. Only drawback of the VIBE effect is that is is really mild and you can really feel it on the high RATE settings. I really wish it was more pronounced. The PHASER swirl effect is milder than the Phase 90 by MXR and it is actually very close to the EHX SMALL STONE which I really like. The Leslie-like whirly effect which is a combination of the VIBE and SWIRL is very good in itself but it only reminds me of the Leslie effect and it, obviously, doesn't have the crunch which accompanies a real Leslie. You can add the extra crunch yourself and get much closer to an actual Leslie sound. Using a fuzz (or better yet the High Tyme Axis/Octavia Fuzz) before the Tri-Vibe on Bass or guitar yielded such a dynamic and rich tone that made me sit one evening playing a single riff over and over dosing off on the guitar. Even the minimum settings on both knobs gives a nice useful hi-pass filtering. I also implemented the suggested mod which gives you the rate indication on the LED which is pretty cool and very useful.

I cannot speak highly enough of this pedal. I can just say that our band's guitarist and me always fight over who will use it on gigs. He actually calls me before each gig to make sure I don't forget to pack it. I guess I might have to build another one. I found a few amazing preset settings which I use very often (in clock numbers for RATE and DEPTH): 9, 3 on Swirl, 11, 1 on Whirl, 2, 2 on Vibe and so on.

The Swirly Vibes patterns

The Tri-vibe is not a Uni-vibe clone and those seeking a Uni-vibe could be disappointing as it doesn't employ the chorus mode which the Uni-vibe is famous for. However as it does have the vibrato mode and 2 swirly/whirly modes, it is a very good replacement and can actually be even more useful than the original. I, therefore, named it Swirly Vibes and painted the enclosure with patterns of waves, swirls and whirls which I really really like. It took me forever to decide on the graphics and after several attempts which failed I went with this great pattern which I got from a designers website.

I discarded the Shake, Rattle and Roll modes naming and just painted a wave a whirl and a swirl to designate the proper switch mode.

This fantastic ROG schematic and layout can be found here. Don't pass on this one. I used the Tri-Vibe name for a while with the old enclosure but after redesigning the enclosure from scratch and putting so much effort into the swirly waves patterns I decided to name it "Swirly Vibes". This is exactly what the pedal does best - swirly vibes.

Bellow are two audio clips demonstrating the Swirly Vibes pedal. One demonstrates the Tri-Vibe with a clean telecaster tone, and the second utilizes the High Tyme Octavia/Axis fuzz in front of the Tri-Vibe. I used all three presets with several settings on each. Just run through the audio clips to hear it's versatility.

The Mixcloud player is slightly less intuitive than the regular Soundcloud because you have to press - "UP NEXT" to get the playlist to show you the tracks, but it is equally well designed.

Tri-Vibe Swirly Vibes Pedal by Doron Barness on Mixcloud

From darkest night to brightest light

Before moving on to more distorted sounds created by fuzz boxes and overdrives, I'd like to share with you a great circuit that has become a crucial part of my pedal board. Playing around with all sorts of amps, guitars and pickups, I realized that I could definitely use some clean tone shaping capabilities.

I started looking for a nice tone stack (EQ) schematic that would give me more voicing flexibility, a clean boost/volume control and a good buffer design. By voicing I mean the characteristic tone of an amp. My Zebra Humbuckers often need a bit more treble to get that shine. A clean boost or volume is very helpful when you place the pedal first in the chain. You can really shape your pickups for more MIDs or less BASS whenever necessary. The buffer compensates for tone sucking when working with many pedals in the chain which are not engaged (OFF position). So after some looking around I realized that the wonderful guys at runoffgroove have done all the hard work already and designed the perfect guitar tone stack in a simple circuit named the Tone Mender. It's a dual stage operational amp with a tone stack between the two stages which gives clean and tunable boost. 

Once I breadboarded this design I knew it was love at first site. Placing the unit between the guitar and a fuzz (not all of them) gave my the freedom to really change the fuzz behavior because you control the BASS content. Fuzz pedals react strongly to the bass content coming in (more bass = stronger harmonics = more fuzz). The MID is like a volume control so you can control the fuzz amount by just lowering signal going in. When placing it after one of the amp emulation pedals you can really achieve different voicings by tweaking the knobs, but it doesn't end there. You can get scooped mids or roll off the bass for less mud. It even has a MID SHIFT switch to choose between the MID control at 400Hz and 700Hz. Cranking the TREBLE knob at the end of the chain gives you extra clarity which is always needed. From darkest night to brightest light. It's all there.

Wow... what a great addition. This pedal just blew me away...mainly because it gives you so many options no matter where you place it. Because it was such a jungle of sounds I decided to paint it tropically and name it The EQUATOR. If you are in need of some tone shaping don't miss out on this one, its simple and super flexible. BTW I ended up using the NE5532 dual op-amp and it sounds great. You can get the schematic and details here.  

Crossing the English Channel

The reason I got into building guitar amp emulation pedals was because Fuzz pedals cannot really produce they're nasty, yet pleasant, sound without the softening effect of the amp and its speaker(s) cabinet. Getting some software simulations of speaker cabinets and connecting the Plexi (Thor) and the Princton (Prof. Tweed) pedals directly to the soundcard's preamps gave me such great results so I thought I better continue my amp overdrive builds and take it further. This time it was the VOX AC30 TOP BOOST emulation achieved by the ROG design which they named the "English Channel". This pedal Rocks!!!

The classic Vox AC amps together with Fender and Marshall form the complete triangle of great 60s amps. The Vox, in a combination with a Fender guitar produced the unique "Western" Shadows sound of Hank Marvin and was used by Vic Flick to record the first James Bond theme. Brian May, Ritchie Blackmore and Rory Gallagher used a Treble Booster pedal to get the amp to sound Fuzzy when overdriven. The bands who cherished this amp go from the Beatles and the Stones to Radiohead, REM, U2, Suede and Tom Petty. It actually has a major part in the sound of the British Invasion. American Garage, Psych and Rock bands of the late 60s loved and embraced the new kid on the block. Because it's a little dark sounding amp compared with Fender amps, the use of the Arbiter Rangemaster as a treble booster became the secret weapon of many players. This kind of boost pushed the tubes in the amp to a unique sound and thus put the Rangemaster treble booster on the same list with other fuzz pedals and made the combination of the two a guaranteed success. Truth is that it sounds great with a lot of fuzz pedals and a Wah just in front.

The pedal as an overdrive can drive single pickups from clean to really heavy drive. Humbuckers sound really fat and juicy and are not that clean on low settings. The tone stack is flexible although I don't find myself using the Cuttoff knob much to attenuate the highs. I improvised the enclosure and got a very good overdrive pedal with a lot of character. You can get the schematic here.

The Rocking Marshall World

The Almighty Thor

If the Fender amps are the trademark sound of the classic American Blues, Rock'n Roll and Country, the Marshall amps are the definitive sound of Rock. Jim Marshall past away a few days ago and it's a good point to bring out another great pedal from Runoffgroove named "THOR". This design aims and succeeds in recreating that vintage Marshall amp character, clean or driven.

This circuit design uses again the Tubes-to-FETs process first suggested by Doug Hammond and later enhanced by the wonderful ROG team. This pedal is inspired by early designs of the JTM and Super Lead Marshall amps. These amps showed up in the UK in the mid 60's after Jim and his son Terry (JTM) tried to design a cheaper version of the classic american Fender Bassman using military American tubes.

Thor's Hammer on

The characteristic sound of these classic Marshall amps, which is the original Plexi sound, is what this pedal is all about. You can get close to the signature sound of Hendrix, Richie Blackmore, Pete Townsend, Angus Young, early Clapton, Steve Hackett, Billy Corgan, Dave Navarro, John Fogerty, Slash, Mick Ronson and the list goes on forever. You have a BRIGHT switch which gives you extra sparkle and a BOTTOM switch giving you more body emulating a large 12X4 Marshall cabinet. The GAIN knob goes from beautiful clean to hard overdriven blues rock crunch which is great for chords or soloing. I have used this pedal for a while now in the studio and live and it's my #1 go-to pedal with a Telecaster. You can get the schematic here.

Below are two clips of a few of the sounds which the Thor has to offer. I played the first clip with HB on a HiWatt amp emulation preset and the second on a Tele with single coils. The tracks are quite lengthy but you can just wonder around and hear what it is all about. As you will hear, The Marshall is the definition of rock guitar sound from Classic Rock, Country Blues Rock, Acid Rock, British Invasion Rock and Prog Rock to Punk Rock, Grunge, Alternative and Heavy Metal, This is the sound.

Hot Cloudcasts featuring Thor Demo by K. Zustang on Mixcloud

Single Coils Tele - Thor - HiWatt amp emulation by Doron Barness on Mixcloud

Amp pedals - The ROG Professor Tweed

After trying a few fuzz designs I started investigating the gear chain of some of my favorite guitar legends and I realized that although the fuzz pedals are a critical part of the chain there are other components which are just as cardinal as the pedals. There is the brain, the heart, hands and fingers and feel of the player. There are the strings, obviously, but once the vibrations are created they are turned to electric current through the pickup coils which are the first major factor in the sound. Mostly you can hear the difference between single coil pickups and Humbuckers. After that you have the pedals, the amp, the cabinet and speakers and the room, microphones and recording gear.

It seems after building some fuzz pedals the next gain stage is the amplifier. I have to give a big credit to the RunOffGroove website from which I learned so much. The guys over at ROG have some fantastic designs of circuits utilizing solid-state FETs to emulate the behavior of driven tube gain stages. With this they designed some serious emulations of classic amps by Fender, Vox and Marshal.

As part of my Fuzz Quest I started off with the simplest design of a classic Princeton amp so I built the Professor Tweed. It sounds like a late 50s amp which can go from clean to overdrive through the input GAIN knob. This was the first time I understood the difference in voicing quality and character between an overdrive and a fuzz. A fuzz is really over-the-top distortion which changes the original sound completely. The overdriven amp stage is softer and crunchier. Although the pedals sound great together with the fuzz boosting the input of the amp pedal, you can use the amp pedal alone as a great overdrive for guitar or Harmonica and it really gives you great classic Blues and Rock'n Roll tone. I have to say that the Professor lacks some sparkle and I always keep its TONE control on max. The mo' bass switch is a nice addition too. I ended up using additional tone control pedal after it to give it more sparkle. Also it sounds better with single coils than with Humbuckers. Humbuckers tend to have higher ouput level and drive the pedal to distortion even at low gain settings. You can get the schematic here.

In the next few posts I'll dive some more into overdrives as it really is part of the story.