I received a Roland AP7 Jet Phaser that was taken out of its original case (top left) and housed in a plywood shell and gigged to no end. The owner is Mitch Jones from Australian legendary post-punk band Scattered Order. The AP7 is a phaser/distortion pedal that provides the swooshing lead sound made famous by the hair metal gods of the ’80s. A six way MODE switch selects between two clean phaser modes, and four jet modes – a combination of differently filtered distortion plus phase sounds. There are also knobs for LEVEL (volume), RESONANCE of the phase and SLOW RATE. The final knob allows a “base slow speed” of the LFO of the phaser that is ramped up to maximum with a stomp of the FAST/SLOW switch. This take-off sound gives the Jet Phaser its signature sound.

I was asked by Mitch to move the RATE switch to a toggle instead of a stomp. In its place, a Mute/Killswitch was put in as he runs the effect into a mixer. The RATE switch is more of a ramp switch, with the rate increasing and decreasing much like a jet taking off! I was also asked to make the pedal extreme! So after much prodding around, I managed to find several circuit bends that took the pedal from an 80′s shred machine to a unique textured phaser. If you have heard Scattered Order, this will fit in quite nicely.

When circuit-bending I aim to provide a few different types of noises. Oscillations (sustained high/low pitched notes) are common, as are different EQ options by concentrating on filter/tone sections. I also like to add in some white noise bends and volume boosts to take the effect to the next level. Luckily, I was able to find all of these bends in this phaser. The video demo below shows the various EQ shifts in resonance, some white noise and some level boosts that work with different frequencies of the effected synth. Also, with circuit-bends being completely chaotic and random, some unexpected combinations of these bends gave some fantastic results.

After bending, I rehoused the pedal into a large new white enclosure, added the MUTE switch and a blue LED to show the rate of the LFO. The artwork is from the cover of a Scattered Order 12″ “A Dancing Foot And Praying Knee Don’t Belong On The Same Leg”.

The video below is a Korg Trident being played through the new AP7 and going through each of the circuit bends to show the combination of new sounds available.

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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

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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

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.

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

The Line 6 FM4 Filter Modeler is a multi-effect unit from Line 6′s popular Modeler range. In this pedal, Line 6 took many famous filter effects, vintage synthesizers and vocoders as inspiration to inspire guitarists to look outside-of-the-box. Most of the models in this stompbox are pure unobtanium – you’d be hard pressed to see one on eBay, let alone have one of your own. The FM4 neatly packages sixteen models, with some sounds instantly recalling musical heroes such as Zappa, Fripp and Frampton. Examples of some of the inspired models are the Mutron III Filter, Oberheim Voltage Controlled Filter, Z-Vex Seek Wah, Korg x-911 Guitar Synth and waveforms from vintage synths such as the Prophet 600 to the legendary Arp Explorer.

This purple beast has four footswitches that allow you to instantly recall four saved presets. The five control parameters allow you to select the Frequency, Q, Speed, Mode/Pitch and Mix of each filter/synth 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.

As you can see in these pictures on this page, I have custom sprayed the once-purple pedal to a Barbie Pink. This is not the colour of the original !

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 FM4 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. Alternatively, if on your pedal board, running your guitar through it will produce a background oscillation (especially in the Synth models) similar to the Z-Vex Fuzz Factory.

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!)

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The Line 6 DL4 Delay Modeler has become a staple on many guitarist’s pedalboards – from professionals to bedroom rockers. It packs 15 different delays into a four stomp box – enabling you to have anything from Floydish tape echos one second to reverse Hendrix solos the next. 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% Repeats and 50% Mix and toe down can be saved for 100% Repeats and 100% Mix. This lets you ride the pedal into oscillation and back it off when it starts to run away.  The three presets give you your favourite sounds one-click away while the fourth switch is a tap tempo control. But perhaps the hidden gem in this versatile pedal is the excellent 14-second looper which lets you record a phrase and manipulate it via a one-shot, reverse, half-time or double-time speeds.

Line 6 also offers more Modelers in this four-button stompbox format: The MM4 is a Modulation Modeler that contains classic emulations of phasers, flangers, tremolos etc. The FM4 is a Filter Modeler and changes the guitar into a vintage synth with a step of a switch. A Distortion Modeler, the DM4, recreates many of the hard-to attain fuzzes, overdrives and distortions. The discontinued AM4, Amplifier Modeler, can also be found on eBay from time to time.

As much loved as the pedal is, it 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 the bottom right of the pedal, adjacent to the tap tempo switch. 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. The knob can be put on either side of the pedal.

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 deafeningly loud, so I have installed a separate BLEND knob to dial in the volume you wish.st be used with caution. The second knob controls the INTENSITY of the feedback allowing control of the amount, pitch, speed of the feedback depending on the delay setting.. A superbright, waterclear LED indicates whether the feedback loop is on or off.

Below is a demo:

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 – NO LONGER OFFERED

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 loops 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.