PLEASE NOTE: THIS MODIFICATION IS ALSO AVAILABLE FOR THE
LINE 6 DL4 DELAY MODELER and LINE 6 FM4 FILTER MODELER

The Line 6 MM4 Modulation Modeler is a multi-effect unit from Line 6′s popular Modeler range. Line 6 provided with this box, a got-to tool for any kind of modulation any musician would need – Leslie tones for the keyboardist, Mutron Bi-Phase for the funk, vintage Fender amp tremolo for the old-school guitarists and off-the-wall ring modulation for the experimentalists. Vox, Fender, MXR, A/DA… they are all modeled here to provide the next inspiring sound at a click of the switch.

Like the FM4, the blue MM4 has four footswitches that allow you to instantly recall four saved presets. The five control parameters allow you to select the Speed, Depth, Tweak, Tweez and Mix of each setting. Expression Pedal control allows you to morph between two different saved settings in the one preset. For example, heel down of the expression pedal can be saved for 50% Speed and 50% Mix and toe down can be saved for 100% Speed and 100% Mix. This lets you morph between these two settings and stop at any parameter along the way – useful for keeping in time with a fluctuating rhythm section.

The Line 6 Modeler range has gained a bad reputation as unreliable due to some design limitations. Firstly, the switches used are not on/off switches, but spring actuators that “click” a surface mount switch on and off. These switches feel unsturdy and are normally the first things to break. Secondly, many users noticed a volume drop when activating the pedal. The output level was affected by component values in the buffer circuit with varied levels of “drop” in different pedals.

The DIY community was pleased when pedal designer Jeorge Tripps (Way Huge, Line 6, Dunlop) released information in tackling these initial limitations, it led to a number of pedal makers and modders to offering their services to improve the Line 6 Modelers. Robert Keeley offers a hi-fi mod involving the replacement of IC chips for Burr Brown’s and some part-time modders (DRASP at Harmony Central Effects Forum) improving on the flexibility of the pedal. After intensive experimenting successes (and failures), cubisteffects now offers a number of modifications to the Line 6 Modelers.

cubisteffects offers not only a modification to rectify the initial design flaws but also has a number of modifications that can improve the flexibility of the unit, and some that push the pedal to become a new experimental tool.

STANDARD MOD

The Standard Modification involves three changes;

1. SWITCHES – The spring actuators are removed and momentary SPST “soft-touch” switches are installed. These switches are screwed to the pedal chassis and are wired to the place of the switch providing thousands of clicks without touching the PCB.
2. VOLUME DROP – Selected capacitors and resistors are removed and, if required, replaced with metal film components.
3. LEDs – The four red LEDs are replaced with superbright, waterclear LEDs of your choice.

EXPRESSION MOD

A rugged 24mm Alpha pot is placed on either side of your preference. This allows you to use the Expression Pedal controls without having an expression pedal take up pedalboard real estate. The modification enables you to save and morph between two settings per preset by rolling your foot over the knob. Settings are saved as per the Line 6 instruction manual.

FEEDBACK MOD

This modification involves re-routing the output of the Modeler back into the input, and the new output selected by a switch on the top of the chassis. This is a feedback loop, and causes spontaneous bursts of noise, squeals, oscillations, drones – all depending on the setting selected. This modification is definitely for the more adventurous musician, but with every effect, the feedback can be used subtly. Most times the feedback can be deafening so it must be used with caution. However, I have installed a small knob that sits aside the switch allowing you to control the amount, pitch, speed of the feedback. A superbright, waterclear LED indicates whether the feedback loop is on or off.

The cool thing with this modification is that the MM4 becomes a stand-alone noisemaker or “synth” as a loose term. I found it best run through a mixer to control its levels more accurately and left as a table-top unit.

Other modifications offered are:

TWIN PRESET MODIFICATION

This preset lets you save two different settings per preset as per the Expression Mod. However unlike the Expression Mod, the two settings are selected via a stomp switch. This allows you to instantly switch between two settings without the need for an expression pedal. The selected preset is indicated by a superbright, waterclear LED.

DISTORTION CIRCUIT BENDS

WARNING: Volatile and extreme modification. Not for the faint-hearted.
This mod involves two circuit bends that work around the same principle as the Feedback Mod but are much more pronounced and distorted. Crackling, white noise, fuzzed insanity can all be activated via two independent toggle switches with a knob controlling the output volume for both. Superbright, waterclear LEDs indicate whether bend is on or off (but you can clearly hear them if they are on!)

C.

So I modded this BRAT in the same vein as the Four Headed RAT mods -  changed the capacitors to hi-fi grade WIMAs, tweaked the buffer circuitry, added a DC jack and a two-way switch to approximate the sounds of Mode 2 and Mode 3 of the Four Headed RAT.

What eventuated was a pedal that now sounded like a true RAT, and more. The pedal become more open sounding with improved clarity and attack in overdrive mode, and the distortion mode had thick harmonic sustain for days. The pedal was also able to clean up better with the guitar’s volume knob to go from a gritty low gain drive to screaming high gain crunch. Not bad for a pink pedal

C.

The ProCo RAT is one of those unique distortion pedals that has its “own sound”. Going quickly from overdrive to flat-out fuzz, the RAT has been the distortion flavour of many guitarists from Jonny Greenwood and Thom Yorke of Radiohead, Thurston Moore and Kim Gordon of Sonic Youth and some classic rock guitarists like Joe Walsh and Jeff Beck.

A big part of the RATs sound is the LM308 – the IC used to provide the distortion tone unique to the RAT; and its pronounced frequency response provided by two R-C networks and the FILTER control. This wide sweeping tone stack allows the RAT to slot into any guitarist’s setup – regardless of the use of a bright or dark amp. Sweep one way and the high frequencies are rolled off, or if you want to cut through the mix, sweep it the other way for more treble. It is definitely an “in-your-face” distortion flavour, that is really closer to a fuzz sound at maximum gain. There are also a number of RAT variants now – the classic “big-box” RAT, small box RAT, the Whiteface RAT, RAT2 etc, all of which contain part of the RAT heritage but with varying levels of tone that make some more sought-after than others.

This variance in the RAT pedal pedigree is what disappoints many guitarists. The RAT has a reputation of inconsistency between individual pedals. I have played some RATs that sound terrific and I wouldn’t want to change at all, but I have also played some RATs that I would never plug in again. This inconsistency is mostly due to cheap parts as is common in a lot of mass-manufactured products. The cubisteffects Four Headed RAT mod uses the best hi-fi components to provide the ultimate in RAT tone for any RAT2 or vintage “big box” reissue. With these changes, the RAT becomes an articulate, harmonically-rich distortion pedal, but also a great overdrive/boost pedal as the new components provide a cleaner, more defined tone than stock.

The cubisteffects Four Headed RAT mod provides four unique gain voicings – two overdrive settings and two distortion settings – to provide the most flexible RAT pedal out there. Each of these settings has something unique to offer and covers the spectrum of low gain blues to super-fuzz stoner rock.

Not only does the RAT stand on its own… four feet, but the two overdrive settings make it a brilliant “stacking” pedal to provide another tonal flavour to your other overdrive pedals. The cubisteffects modded RAT combines with other drive pedals to provide complex and louder crunchy tones. A lot of the clean signal can be heard when the DISTORTION knob is rolled off and this is ideal when boosting another overdrive or fuzz pedal. Your tone will retain its responsiveness to your playing even though multiple pedals may be stacked.

I offer two stages of modifications of the cubisteffects Four Headed RAT mod: the STANDARD mod and the NOISE mod.

STANDARD MOD

The Standard Mod changes involves four changes:

1. CAPACITOR CHANGE – All capacitors are replaced with hi-fi WIMA capacitors, used in the best audio devices around the world. Every capacitor is changed in the Four Headed RAT mod providing a clarity and more complex sound unique to this mod. Also, certain values are tweaked to capture the tone of the early 80′s RATs.
2. IC CHANGE – The backbone of the original RAT tone was in the LM308 IC chip. Newer RATs have the OP07DP chip which although sounds similar at high gain settings, really differs in the lower gain territory. The LM308 has a different dynamic range that allows it to clean up and be more responsive to your playing. It also sounds more smoother and has less high-end fizziness that the newer OP07DP RATs have. The Four Headed RAT involves replacing the OP07DP with an LM308 chip.
3. DC JACK – the small DC jack that comes stock with the RAT is changed for a “BOSS-style” jack, making it easier for daisy-chained pedal boards.
4. THE FOUR-HEADED KNOB – This four-way switch selects between four different gain voicings. The red chicken-head knob transforms the RAT to a tame low-gain drive to a wild, fuzzy monster.

Each of the four gain voicings are described below:

MODE 1 – Vintage Overdrive – This overdrive setting sees a blend of your clean guitar signal and a slightly fuzzy overdrive signal. The use of germanium diodes provides a spongy overdrive great for blues.
MODE 2 – Overdrive and Boost – This setting has a slightly higher volume than Mode 1 but still has a good balance of clean and overdrive signal. This mode is great for rolling back your guitar’s volume for a crystal clear clean tone and rolling it forward for big harmonic drive.
MODE 3 – Rock – This mode is closest to the stock mode of the old-school RATs. The new components, plus the standard silicon diodes, provide the classic RAT tone but with a richer, more complex sound. This is how a RAT should sound with a more balanced bottom end and less high-end fizz to give a well-rounded rhythm tone or an overtone-rich lead.
MODE 4 – Fuzz -  The fuzz mode takes the gain to another level with a really sagging, compressed sound. Roll up the FILTER control and you’ll have Kyuss riffs for days! Turn the DISTORTION all the way up and the fuzz starts to really dip with the guitar’s attack left dead. A really over-the-top and unique fuzz sound that will have people wondering “What the hell was that?!”

NOISE MOD

In addition to the Standard mods, the Noise mods see the addition of two features that take the RAT into noisy, feedback territory. All of these mods can be used in conjunction with the Standard mods so you can have your polite, low-gain boost or you can have an oscillating, filtered wild rodent all in one!

1. frEQ POTS – Two pots control the response of the FILTER control, and affects the gain at the same time. Roll each all the way down for a crisp, tight drive sound or push it tom maximum to get squeals, oscillation and Sonic Youth feedback all in the stomp of the RAT.
2. OSCILLATION SWITCH – A two-way switch selects between Standard Mode or Noise Mode. Noise Mode introduces a howling pitch of feedback that can be tuned with the DISTORTION knob or your guitar’s volume/tone knobs. The feedback can be blended to the back of your high gain signal or even be heard over your clean signal.

Below is a video demo made by Jon at Guitar Noize. He has an awesome guitar blog with up-to-date news items and gear demos like the one below. Jon goes through the four modes of the 4HRAT with some nice playing to boot.

Four Headed RAT Mod – Clean Riff by cubisteffects

This clip goes through each of the four modes of the RAT at half distortion. All pedal settings (D: 12 o’clock, T: 12 o’clock, V: 3 o’clock) are the same and only the red knob is turned. Notice the increasing amount of gain and harmonics as it goes from overdrive to fuzz.

Four Headed RAT Mod – Half Distortion by cubisteffects

This clip again goes through each of the four modes of the RAT, but this time near full distortion. All pedal settings (D: 4 o’clock, T: 12 o’clock, V: 3 o’clock) are the same and only the red knob is turned. Notice the loose spongy sound of the overdrive mode compared to the tighter mode 3. Also, the fuzz really starts to kick in and splutters its way through to the end.

Four Headed RAT Mod – Full Distortion by cubisteffects

This is a custom pedal that I built that was based on the Univibe – a foot-controlled phase shifter that can produce “chorus and vibrato-esque” effects. However, the pedal has its own distinct modulation sound that has been immortalised by guitar legends such as Robin Trower, David Gilmour and Jimi Hendrix. It can be smooth and subtle to throbbing and percussive – enough to make you seasick after awhile!

This layout and PCB (called the Neovibe) was designed by DIY pedal guru, R.G. Keen who started GEOFEX, is an active member of DIY Stompboxes and now works for Visual Sound. The design is centered around a lamp as the light source that responds to a staggered phase stages, with photosensitive resistors responding to the amplitude of the lamp brightness. The pedal involves making a light shield to optimise the response of the photosensitive resistors by placing the lamp in a dark, contained area. The use of the lamp – the core of the traditional, vintage Univibe – provides a lagging, spongy latency that is unique compared to other modulation pedals like chorus and vibrato. For the tech heads, Keen has written an excellent article on The Technology of the Univibe.

This Neovibe has standard Volume and Depth controls on top, with a Chorus/Vibrato switch between them. To emulate the foot control without an expression pedal, the larger speed knob was placed on the side allowing the rate of throb to be controlled on the fly. Check out the demo at the bottom of the page.

Chris Tamm aka Konsumterra has been involved in street art for nigh 20 years with paste, stickers, stencils and character art. Originally from Adelaide, Chris is currently in Sydney working as a street art teacher, curator and artist. Most of Konsumterra’s work is a parody of consumerism and a celebration of low pop and trash culture.

Check out his work at http://www.flickr.com/photos/konsumterra/

Below is a demo of the Neovibe.
Clip Details: Fender Stratocaster > MI Audio Blues Pro Overdrive >Neovibe > Marshall JCM600
MI Audio Blues Pro kicked on halfway through.
Recording: SM57 > Mbox2 > Logic Pro

Neovibe by cubisteffects

…and here is a demo from the Neovibe’s new owner

C.

Diamond Guitar Pedals, from Halifax, Canada, are an example of the awesome guitar effects builders coming from the land of True North Strong and Free. Again, reputation precedes them, having released a number of outstanding designs led by the desirable Memory Lane Delay pedal. Having created a number of excellent modulation designs, such as the Halo Chorus and Tremolo, it is no surprise that this Fireburst Fuzz/Distortion retains the same complex tones and flawless design.

I picked this one up from Dave at Bondi Guitar and Sound Gallery. He has an excellent collection of pedals in hos store and this one was no exception. After repairing a sticky switch, I couldn’t help but admire the PCB layout; all of the components neatly aligned, trimmed and taut wiring, clearly the work of an obsessive-compulsive personality

The build quality really matches the design as low-end driver morphs from a complex fuzz to tight distortion with a literal flick of a switch. The mid-boost switch fills out the frequency spectrum tapered by the Baxandall Bass/Treble tone stack. It really fills in the lower and upper mids, and provides great harmonics reminiscent of a full, thick distortion. I really admire the thought behind this design proving great ideas provide great tone.

Frantone are now a company dealing with custom-ordered pedals, boosting the value of older pedals such as the Brooklyn. I received this one dead after the wrong power supply fried a few components. Opening it up, the internal build is excellent with a great relay switching design. After replacing the said components, the pedal roared back to life.

For an overdrive, it definitely has a lot of fuzz gain on tap – reminiscent of the Skreddy Screwdriver Overdrive. This overdrive, like the Skreddy, sounds as though its lineage has evolved from the Big Muff design, especially the interaction of the tone stack. But this pedal is very touch-sensitive and responds beautifully to the dynamic changes with pickup selection. It can be a clean, open boost or a rich, complex fuzz with loads of volume to boot. This one’s a keeper!

Welcome to Part 3 of the Mod.It.Yourself series where we have previously looked at the basics of Tools and Techniques in Part 1 and how to mod the Diode Clipping in a pedal in Part 2. Part 3: Switches will look at an important component in the pedal modder’s toolkit. Switches are mechanical devices that allow an instantaneous flip to either turn part of a circuit on or off (break the circuit), or introduce a new part to the circuit. The latter function is useful in doing reversible modifications, or mods that use the original stock component. This part of The M.I.Y series will explain a bit about common switches and some ideas on how to use them in your own pedal mods.

The two most common mechanical switches used in modifying pedals are the push button switch and toggle switch [above]. Both of these switches use common nomenclature for their components that must be understood before selecting them for your next project. Below is a look at some of the more common names of switches that are used for pedal mods and an explanation of their specs:

Each switch is named with respect to the functions of their contacts, i.e the part of the switch that is in contact with your wire, component, PCB etc. Also called a lug or pin. The two terms are poles (denoted by P) and throw (denoted by T). A pole is the number of switch contact sets of pins/lugs, and are labelled SP- for single pole, DP- double pole, 3P- for triple pole etc. The diagram [below left] shows the poles of a 4PDT switch.

Most switches used in pedals have three pins per pole. The center pin is common ie. is always connected to either outer pin of the three. Moving the toggle either up or down selects [above right] between these two connections or conducting positions. These positions are known as throws and are denoted -ST for single throw or -DT for double throw. A single throw switch only has two pins with the third pin shorting to ground, thus having only one position.

Common switches used in modifications are single pole double throw (SPDT) or double pole double throw toggle (DPDT) switches, and true bypass foot switches are known as triple pole double throw (3PDT). So using this knowledge of switches, here are a couple of mods you can try on your next pedal designs or mods.

KILL SWITCH

To get a stuttering effect made famous by guitarists Tom Morello and Buckethead in stompbox form, you can make use of a type of push button switch called a momentary switch. By using a push-to-make momentary or “normally open”, when pressing the switch you are breaking the circuit thus creating a staccato effect. To do this, all you need to do is cut the wire that goes from the output of the PCB to the bypass switch. Wire each of these two ends to a normally open SPST momentary switch and you have a momentary kill switch [diagram below]. The effect signal will stay on until you step on the switch, cutting all volume of your signal. By pressing at rhythmic intervals, you can create unique guitar rhythms heard in many RATM riffs. Momentary switches are great for these “stab” like effects and can be used for feedback loops, or wiring to a potentiometer in a delay pedal to get that spaceship, oscillation sound.

DIODE  CLIPPING SWITCH

As previously discussed in Part 2 of the M.I.Y series, we can mod a pedals’ clipping diodes to create a different tone of the distorted sound. We could use different diode material , symmetry, combinations etc to get our desired sound. But what if you liked two diode sounds and wanted to switch between them? Using an SPDT switch, you can do just that and is a common feature on many effects pedals.

The schematic [above left] shows the clipping diode structure of many distortion pedals – a hard clipping pair at the output of the IC. One end of the pair shunts to ground, while the other end is in the signal path. If this end on the signal path (A) is wired to the common pin of the SPDT switch, we can then switch between two differing pairs of diodes. Wire the end of two pairs to ground, and the other end to (B) and (C) of the switch and you can select between your favourite clipping tones [above center]. The symmetry of the clipping can be controlled using this switching layout as well – just use different symmetrical pairs for (B) and (C).

You can also use this principle to switch between two components of differing values ie. the output capacitor to provide more/less bass into the circuit. Remove the initial capacitor from the PCB where one pad will have one wire running to (A) and two wires from the other pad to one end of either capacitor you wish to switch between [above right].

Hopefully this info and diagrams will give you ideas on how to mod your next pedal, or to modify your next pedal build. Also, I would suggest getting a multimeter with a continuity test function. By putting either probe on any two connections, a beep or sound should be heard. This is very useful to test your new connections.

Happy modding,

C.

This is a custom pedal that I built that was based on the DOD 250 Preamp Overdrive. This is a great pedal to build for someone looking for a DIY project. The circuit is very basic and has a 741 op-amp at its core. The original grey 250s (pictured left) go for a pretty penny on eBay, and the newer reissues (also pictured left) are also climbing in value. The pedal even garners a special fan, Yngwie J. Malmsteen, and his fandom of the small grey box has earned him a signature YJM 308 Overdrive – again based off of the 250 circuit. In my opinion, it is a very under-rated overdrive pedal and had the potential, with some cubisteffects mods, to really become a versatile low/mid gain drive pedal.

This custom 250 has two footswitches – one for bypass and one to activate a clean boost. The boost can be used independently of the 250 circuit, thus providing three levels of gain (boost, custom 250 and custom 250+boost). The white knob controls the output volume of the boost.

The four black knobs control the Volume and Gain (as per the original design) plus a few modifications. There is an “Edge” control that limits the amount of signal hitting the clipping diodes. This provides a smoother tone and effects the character of the gain in a different way than rolling of the Gain knob. The fourth knob is a Tone control that rolls off high or low frequencies, and can be bypassed by the small toggle beside it. Bypassing the tone stack increases the output volume significantly and can really drive your preamp! The large toggle is a three-way switch that selects between three diode selections providing three different tones – fuzzy, boost and smooth. All of this in a hand-painted custom black and white swirl paint job as well.

So here are some photos of me, my work and my shit. Be sure to check out his awesome photos of the Sydney music and art scene at www.willreichelt.com. Click on the pic for a link to more cubisteffects shots…

C.

In 1965, British electronics guru Gary Hurst began the UK fuzz pedal phenomenon with the building of the Sola Sound Tone Bender. This pedal, the MKI, was an advance of the Maestro FZ-1 and ran off 9V to give more sustain and output volume. These pedals provided the tone for guitar gods Pete Townsend, Mick Ronson,The Beatles and Jeff Beck. Further iterations of the Tone Bender (MK1.5 and MKII) are highly collectable units these days as that sound has been immortalised by Jimmy Page and that guitar tone captured on Led Zeppelin records.

Colorsound are a company that recreate some of the pedals that Sola Sound introduced in the golden era of rock and roll. These include some of the Sola Sound wahs, fuzzes and different versions of each. I got this Colorsound Overdriver Boost pedal from local Sydney muso Jeff Burch, who plays with a number of bands like Songs and The Mandala Trap. The Overdriver is a silicon transistor based pedal (whereas the Tone Benders were germanium based) that has a really usable Bass/Treble tone stack and a Drive control that lets you dial in the amount of gain you would like. The last turn of the Drive knob gives a nice bit of growl while retaining articulation and response.

He really liked the pedal but lack of LED and 9V DC jack limited its functionality on his board. So I added a yellow superbright LED with chrome bezel, true bypassed the sucker and added a DC jack.

C.