HNPD - Line 6 MM4 that I rebuilt

[Modern Saint]

About 3 weeks ago I bought this Line 6 MM4 for $100. Tracing the serial number my unit was made somewhere between 1999 and 2002. When I was researching the MM4, I found that there was many improvements one can do to the unit, so sit back and enjoy the ride.

You know I can't keep things alone

Time to take the unit apart.

Underside

Bottom Panel Removed

Knobs Removed

Rear Shot

Nuts Removed

Board Removed

Switches Removed

These Switches are what cause all kinds of problems for these Line 6 type pedals. These switches have met the trash can.

 

[Phil513]

Coolness.

 

[Modern Saint]

The early MM4 I read had problems with the volume. When the unit goes into bypass, the volume drops so a couple of resistors are going to get replaced. There are also some caps in the that tone suck so they too will get removed.

The MM4 Board

Resistors to Change - R36 and R37

Resistors Removed

 

[telecaster911]

Cool stuff

 

[Modern Saint]

Caps C1 and C36 from the input need to be removed to prevent tone suck

Caps C23 and C24 in the output section also to be removed for more prevention of tone suck

Components have been all removed including SW1 through SW4

24K Resistors added to replace the original 36K resistors.

 

[Modern Saint]

With all of the components taken care, it time to take care of the case.

Using KleenStrip that you can get from Walmart - use gloves - it time to strip the paint.

Got the case in container and the stripper is poured on.

Using a toothbrush and two applications of KleenStrip, we get a pedal case with no paint. Note that once that paint is stripped, you will need to neutralize the stripping solution - use warm water and dishwashing liquid.

 

[Modern Saint]

Time to apply the Blue Paint - I used 3-4 coats of Rustoleum Metallic Blue

After a few days of drying, I shot the case with some Rustoleum Crystal Clear Gloss

Added the plates back on with some Scotch 77 adhesive

Wired up the new momentary switches for the pedal

Switches Installed

 

[Modern Saint]

Switches are installed on the topside

With Switches Wired and Soldered, I reassembled the unit. Also replaced the original black knobs with 6 new white knobs.

Woo Hoo - A brand new unit....well brand new looking!

Now one of the coolest things I did to add more personality to this baby was to change the color of the LED's

My patch selections are identical to Mike Campbell's of the Heartbreakers. After that is what this pedal will be used for.

Memory #1 - Preset is the Leslie patch (Orange LED)

Memory #2 - Preset is the Tremolo patch (Red LED)

Memory #3 - Preset is the Flanger patch (Blue LED)

and Memory #4 - Preset is the Chorus patch (Green LED)

The unit sounds great. I could more crazy with a couple more steps that others have done but I am not planning on it....unless I get another one for cheap. The other mode is the Brown Burr mode which would help improve the fidelity.

However with the caps removed and the new output resistors in place, the unit sounds great.

 

[jaxn slim]

That is so awesome, Randy.

 

[Mark Wein]

Sent from my iPhone using Tapatalk

 

[Chad]

Very nice work Randy. You are pretty damn good with a soldering iron. You could make a killing in the boutique market.

 

[MonkeyZero]

That's sweet! I want to do stuff like that but I'm all shakes.

Sent from my Galaxy Nexus using Tapatalk 2

 

[Modern Saint]

That is so awesome, Randy.

Thanks Jaxn! Finally got one as we discussed previously.

Very nice work Randy. You are pretty damn good with a soldering iron. You could make a killing in the boutique market.

Thanks Chad! I'd probably make more money selling GFS stuff

That's sweet! I want to do stuff like that but I'm all shakes.

Sent from my Galaxy Nexus using Tapatalk 2

Thanks MZ! As for the shakes, didn't know what I was getting into in regards to the MM4 project. Much of it was what I read on the internet regarding the unit. But I found some reputatble sources confirming all of it. Either way the one thing that would have happened are the switches being changed which is the biggest issue with this series of units. There is a video on You Tube of someone changing the DL4's switches which is an identical unit to the MM4 except the eProm. All the other changes were supposedly remedied in future versions of the MM4 units.

There is another mod that I thought of taking on but decided not to. It is the Brown Burr mod which replaces a few caps and two surface mount chips. This would improve the fidelity of the signal because of the chip quality. However TL071's are pretty good already to begin with so I passed.

Oh yeah to add, you just got to go for it dude! The more you do it, the easier it gets.

 

[Kerouac]

Looks great man!

 

[Psychotronic]

Awesome!

 

[baimun]

What's the work to results ratio.... is it something that you would consider doing as a mod for someone else? (not necessarily me, I don't normally care for L6 gear).

 

[Modern Saint]

What's the work to results ratio.... is it something that you would consider doing as a mod for someone else? (not necessarily me, I don't normally care for L6 gear).

Regarding the mods - electronics only!

Switches - JHS charges $55

Mod took me about 1 hour to replace 4 switches

Hi-Fi + Volume Loss Mod - JHS charges $75

I only performed volume loss mod - 1 hour
add 30 minutes if I did Hi-Fi mod.

Here is the link to JHS.

http://www.jhspedals.com/products/mod-shop/line-6-mm4-mods/

As for the paint job, that was for me along with the LED's.

 

[NothingClever]

What settings do you use for your leslie patch? I am struggling to get that Campbell Echo era sound.

 

[Modern Saint]

What settings do you use for your leslie patch? I am struggling to get that Campbell Echo era sound.

I must've missed this. I will post when I get back home tomorrow.

 

[Bob411]

HNPD. and thanks for posting all the pics. Great stuff.