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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Malekko are one of the most innovative pedal manufacturers around today. With a small stable of products, their quality and performance are up there with the best. One of the most highly anticipated releases was this one above: The Ekko 616 Analog Delay. This small footprint pedal provided everything a classic modulation delay could do – subtle chorus to wild vibratos, 600ms of analog delay, and selectable buffered or true-bypass all running off 9V.

However upon release, a small number of units had incorrect parts that produced a heavy distorted repeat signal and a smaller regeneration range leading to fast oscillation. Although the problem was quickly fixed for future production runs, a small number still contain this incorrect parts.

I fixed this one for a local Sydney guitarist after contacting Josh at Malekko. He has sent me kits to repair any other malfunctioning 616′s for anyone in Australia/New Zealand. If you do have a faulty 616, drop me or Josh an email and I can offer this repair free of charge.

Once fixed, the pedal was back to its finest, with smooth warm decays and haunting modulation - a serious contender as best analog delay on the market. Stay tuned in 2010 for the Ekko 919… this Ekko’s big brother. Here is a demo of the Malekko Ekko 616 Analog Delay, courtesy of Pro Guitar Shop:

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Analog delay pedals have become a staple to many musicians’ arsenal. They are known for their rich, warm repeats that adds some space to a wide range of tones from fat synth lead lines to echoing guitar solos. This tone is highly sought after for its vintage vibe, and differs from digital delay in providing a “natural sounding echo” with each repeat getting darker and darker, until fading away. This effects has several uses over a range of delay times from doubling (or thickening) to slapback (one quick short repeat for a reverb-like effect) to delays up to 500ms. Another feature of analog delay is its ability to self-oscillate -that whirring, spaceship sound that has been used in many recordings in the past. By turning the repeats to maximum, the delays continue to build and overlap into a blur of sound that many musicians manipulate to form textures or soundscapes.

The Ibanez (and Maxon) AD-9 have been adopted by pedal modding gurus, Keeley and Analogman, as a re-issue worth modification. These re-issues sound great when compared to the originals and are half the price new compared to buying originals on the second-hand market. However, analog delay junkies tend to obsess about their tone, and true bypass is a good option to preserve your guitar to amp sound. Keeley/Analogman would add true bypass to these pedals by installing a secondary footswitch on the pedal. Keeley goes one step further by using the original momentary switch to make the pedal self-oscillate providing a very flexible and neat delay.

I got this Ibanez AD-9 up and running after having had a power problem. After repairing the problem and changing the power filtering caps, I modded the pedal ”Keeley/AM-style” with a 3PDT for true bypass*, a bright waterclear blue LED replaces the stock LED and the original switch also triggers the pedal into self-oscillation by holding down the switch.

*The method I used to TB disengages the Dry Output. This isn’t necessary but I found it easier to do.

This demo is courtesy of guitargear.com.mx. It shows the warms sounds of the AD-9 and the cool oscillation switch mod.

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This Electro Harmonix Deluxe Memory Man arrived at my door looking like the road-worn beast you see above. This big box analog delay is a favourite among many musicians and this one has seen a gig or few. But when opening it up, I also realised it had seen the rough end of a soldering iron. Some PCBs and pedals (especially Electro Harmonix ones) are very fragile and do not like too much heat. If you do not have good soldering (and as important, de-soldering) technique, too much heat will inevitably be applied. Tracks will be lifted with no solder flowing through the component holes. This poor DMM had burn marks, cold solder joints and globs of solder on the PCB. One of the best tutorials I have seen for soldering and de-soldering is from the guys at Make Magazine. A worthwhile 19 minutes to brush up on your soldering skills. Just excuse Joe’s inability to correctly pronounce the word “solder”

On this pedal, true bypass was attempted, although the indicating LED was wired in reverse and some foam was stuck to the board to hold some wires in place. Unfortunately, the rich, warm echoes of this pedal were distorting badly so a re-calibration was required. The re-calibration involves finely tuning five trimpots with the aid of a function generator, oscilloscope and a good set of ears. At least I have two of those.

After fixing as much of the previous damage as possible, an input gain reduction mod was done to reduce the clipping of the first stage of the pedal. Sadly it wasn’t a completely happy ending. The BBD chips were the culprits of the distortion and are hard to replace, and it could only be re-calibrated to 75% working order. But still, hidden amongst the burn marks and solder globules, were the dark, haunting vibrato repeats of the Deluxe Memory Man, keen to hit the road for a while yet.

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Unfortunately some of the toughest pedals to bring back to life are digital pedals that no longer power up. This is due to incorrect powering such as too much voltage or the use of a power supply of incorrect polarity. This Boss DD-20 Giga Delay is one such example. There was no power or audio signal but on closer inspection no ICs or voltage regulators were damaged. A replacement of a SMD protection resistor resurrected the pedal with a flurry of flashing lights. This one is a success!

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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.