M Series Audio Upgrade (AU): M9 $105 - M13 $125 - M5 $95

Reduces background noise
Adds remarkable increase in fidelity and clarity
Effects are more profound and detailed
Clean signal is far more robust and clear
Adjustable analog master output for the pedal when effects are active or in DSP bypass mode

The Short of it:
The signal path between the input and output is upgraded and altered with audiophile grade passive and active components to maximize the efficiency of the stock CODEC. The analog to digital conversion process is fed a more pristine signal with extended headroom and added muscle from the power “rails”. Between the balanced CODEC output to the line level outputs, the signal path is streamlined to invigorate and protect the integrity of both effected and clean tones. Leaving the pedal in DSP bypass or “spillover” mode is no longer at the expense of your tone.

Replacement Switches

M9 $89
Replaces all 7 factory PCB mounted switches and plungers with new self-contained smooth action components.

M13 $145
Replaces all 15 factory PCB mounted switches and plungers with new self-contained smooth action components.

M5 $45
Replaces both factory PCB mounted switches and plungers with new self-contained smooth action components, and stock red LEDS with blue. All components are bolted securely to the case.


Remote Tap Jack
M5, M9, M13 $40 ($25 when combined with other modifications)

Input tempo remotely with a normally open type switch (sold separately) or sync with other time based effect pedals that have an isolated remote tap jack via an MTPro.

Dedicated Scene Select Footswitch M5, M9
$40  ($25 when combined with additional modifications on the M9 only)

Access the scene select screen on the M9, and the preset scroll function of the M5 with one footswitch. This helps you avoid the awkwardness of missing the two switch combination on stock units. Once activated the selection process is the same as before. (Note: Because of the extensive re-working necessary to fit this modification into the M5, the combined discount is not applicable)

Expression Switches for M9, M13
$40, 2 x $70 (latching with LED)
$25, 2 x $40 (momentary without LED)

Simulates an expression pedal in “heel down” or “toe down” positions. You may already be familiar with this feature of Line 6 Modelers enables two different settings (same delay model but different tweak, tweeze, time, feedback, and mix) per preset enabling you to morph between settings with the expression pedal. By following the related instructions found on page 3.3 of the Line6 “M9 Advanced Guide” and pages 2.2,3.3 of "M13 Advanced Guide” you can set up these two unique combinations per preset then have instant access to both with this new switch.

For the M9 Expression Switches are installed on the top deck of the M9 above FX1B and FX2B. When adding two Expression Switches AND a Scene Select switch, the later is installed just to the left of the main display. The AU

Latching switch* 

Includes an indicator LED that is mounted near each switch respectively.

Momentary switch*

These smooth type switches allow you to instantly jump to one expression setting when pressed down and immediately return when released. Allows you to pulse expression setting for interesting sounds. For instance, a two octave up setting works fantastic with this mod! Does not include led indicators. 

(Custom Options: If you'd like your switch mounted in a different location email me with your idea and we'll explore the possibilities; The “Expression Switch” feature can be accomplish with a small external switch and red indicator LED)

*When using an external expression pedal, the mod is bypassed and the factory expression feature functions as normal.

M Series Repairs

Switches aside, the M series from Line 6 is a very robust platform, and most any component failure can be repaired. Whether you have a loss of audio, intermittent signal, broken knob shafts, broken AC jack, failure to power up etc. I can fix it. Simple knob replacements to more complicated repairs (replacing CODEC) range from $40-$80 plus return shipping. The fix related to M9's with a serial number including S5934 is $50 plus return shipping. 

If one of the normal upgrades actually corrects your problem there's no additional charge. If having an upgrade in addition to repair work you may be eligible for a discount towards the repair labor.

Why is it necessary to replace the stock switches?

  • Another great pedal series from Line 6! But design (think DL4) again may have been a casualty to bottom line leaving the pro player wanting a bit more.
  • Replaces all stock surface-mount switches and actuators with smooth action robust self-contained momentary switches for years of professional use.
  • If you often need to input tempo with the stock switch it will fail sooner or later depending on your angle of attack. A failing actuator to surface mounted tactile switch will typically fail in the following progression:
    • As vague as this sounds, initially they’ll seem stiff every now and then
    • The time it takes the pedal to recognize your input will begin to seem “off” (especially on the tap switch) 
    • It becomes increasingly difficult to lock in the desired BPM as a the duration of useable tempo’s interval decreases before it’s necessary to re-tap for a musical sync to rhythm.
    • The switch will completely lock up but will work again after forcefully striking it with your foot, beer bottle, or wah-pedal (none of which are recommended)
    • After the previous resourceful attempts to free the switch help less and less the switch no longer functions at all.
    • Influenced by an overwhelming feeling that “this used to fix it”, too much force is applied to the switch hastening its destruction.
    • You pray that some poor sucker on E-Bay will never notice the difference, or you rant on a gear forum until you feel better.
  • Life is short, don’t let a bean counter keep you from enjoying your favorite pedals.

What clients are saying about the changes:

Thanks for working on my M9.  It seems better than ever so far!  I’m glad I decided to do the audio upgrade as well as the two expression switches.  Thanks for your patience and quick turn around!

Got the M9 back today.  The switches feel great, and I’m looking forward to my looper not turning itself on and off during shows. :)  I’m really digging the audio upgrade, too.  I have to readjust the parameters of pretty much every patch I dialed in, and they’re coming out fantastic. Definitely a worthwhile upgrade.  The master volume control seems to be at unity at noon or just above…it varies with each patch right now.  I can level them out, though.  

Thanks so much for the great work and speedy service! I’ll be recommending you to everyone I know with an M-series pedal. 
Justin Ostrander

Story behind the mod:

While changing the switches on an M9 I spent a bit of time playing around with all the cool effects and layers. The idea is brilliant, and I wasn’t disappointed by all the different models, old and new. When comparing the bypass settings (with the guitar volume rolled off) I noticed a bit of noise, and while playing through the various effects it felt like the sound was “throttled”. 

After finding a willing M9 owner, I began to apply the same principle changes found in the Audio Upgrades for the DL4, MM4 and Nova Delay. After a long time tracing the circuit and becoming familiar with what was going on, I started making changes. All of the electrolytic capacitors in the audio path were replaced with the same type of audiophile quality parts that I use in all JHV3 pedals and mods. In most cases the values of these particular caps were increased. Several surface mounted coupling capacitors were exchanged for very high quality, full sized metal film replacements. The nine industry standard low noise operational amplifiers in surface mounted packages (2 quads and 1 dual) were the next to go, replaced with superior sounding opamps noted for their ultra low distortion, low noise and very high speed. The later is important to more accurately reproduce the complexities of the original guitar signal and effect. These opamps receive power from +/-12v rails. To reduce the allowed margin of power sag from the stock unit, the supply and filter capacitors are also replaced with more robust and reliable pieces that are often found in the best audiophile power supplies. 

After the changes:

My first impression was “WOW!” (and “whew”, after all of that, it better sound great). The noise in bypass was reduced but the most noticeable difference was detail. Like adding a great buffer to capacitively troubled pedal boards and guitar/amp cables, the high end was clearer and more present. While sweeping sine waves through the unit a oscilloscope confirmed that highs were being restored vs. increased, similar to the effect of turning the tone knob of your guitar from slightly on to off.

To address prevailing misconceptions and misused vocabulary about gear that “sucks/changes my tone” (as it pertains to the psychological and emotional embrace of any given piece of guitar gear) I experimented with output component values to get the most even and accurate reproduction of dry signal between the DSP and Relay bypass modes. By ear, oscilloscope, and by the ears of other less fortunate souls trapped in the shop, I tweaked the output until there seemed to be no one combination of values that would satisfy all. Most players perceived the increased clarity in highs as a decrease in bass. Even with a scope empirically screaming otherwise, this is what most people “heard”. To address this issue and try to avoid reduced income burned up by forum flames, I made the output variable. Now with a bit of tweaking and an a/b process between completely dry signal in DSP bypass and true bypass anyone can dial in the closest match between the two.

Please Note: Line 6 is an outstanding company that has consistently produced stellar products designed by some of the most brilliant minds in the industry. As many of these innovators moved on to start their own companies they continue to raise the bar on the standards by which all others are compared to. Unfortunately for any company, mass production and profit margins means parts are chosen that fit within an acceptable margin of error/failure/accuracy/price which are most efficient/profitable to use in the process of manufacturing. Brand new and right out of the box these pedals do something great and remarkable which hooks us into an initial investment in the piece. But everything can be better! The modifications JHV3 make to stock Line6 pedals replaces key parts with superior parts that otherwise would have driven the price of these units out of reach for most.