MXR Distortion+ with a tube (pics).

[brad]

 

Here's my first attempt at putting a tube in an MXR Distortion+.  When I first started breadboarding this back in Janurary, I was let down with the results, but I kept at it until I eventually found something that sounds great!  This pedal is specifically a bass distortion.  Building this thing was a total PITA.  The tube is recessed about a centimeter into the battery compartment with all the associated components free-formed in what little space is left.  I don't have an electric drill, so all the holes were drilled with one of those old-style U shaped hand drills!  The hole for the tube was made by drilling lots of little holes and filing it out to the right size.  Just thinking about it again makes me cringe    This version was really just to prove to myself that this pedal (modification?) can be done, and I'll be using a much neater layout on the next one...and it will have much better protection for the tube too.

Hopefully I'll be able to make one that looks appealing enough to sell.  My income during the semester is nill -hence not being able to afford an electric drill!

[brad]

Ack...it's a shame I don't know how to take pictures in the dark.  The tube looks really pretty all aglow.  If you can't tell, that orange dot in the picture on the right is all that remains of said glow under the power of my desk lamp.

Oh!  I'd better clarify that it's not Stephane's 12AJ6 buffer in there either!

[Bernardduur]

Very nice!

[H.Manback]

Wow, that is.. interesting

Looks very cool this way too, and it must have been a lot of work doing all that without a power drill..

[Herr Masel]

Wow, congratulations on the effort, it reminds me of the pic from geofex... , how different is it from the original? I guess you had to change a whole lot of components and then some to accomodate the tube and make it work for bass, so maybe that's a difficult question. I think an ok idea for the design would be to build a metal extention mounted on a hinge that would protect the tube, and opens up kind of like a cigarette box.

[Satch12879]

It looks like a phenomenal job.  I would have rehoused it, but that's neither here nor there.  I'm assuming the tube consitutes the standard bypassed cathode input stage on every amp since the beginning of time?

[Also Wik]

Looks good! I'd be afraid to kick that tube, though...

[JimRayden]

That makes even Ton look like a sissygirl. No offence intended of course.

Hmm, you could make the protecting piece of metal go all the way around the tube. By the way, what's the circuitry? A modded D+ or a whole new one?

----------
Jimbo

[brad]

I'm assuming the tube consitutes the standard bypassed cathode input stage on every amp since the beginning of time?

Nope!   

That makes even Ton look like a sissygirl. No offence intended of course.
By the way, what's the circuitry? A modded D+ or a whole new one?

Puretube probably used a vacuum tube in this way before he learned to walk!  It's not that complex.  The hard part was getting it to sound good because a lot of the tweaks I tried along the way weren't that great.  There's still an MXR Distortion+ inside there, but the stock values have been changed and some extra stuff needed to be added.  The reason I modified a commercial pedal is purely because of time constraints.  I only have enough spare time to be able to make one of these about every two weeks.

[moody07747]

thats a great mod.

im going to be building a MXR DISTORTION + and now i really want to add a tube to it.

You wouldn't happen to have a nice detailed layout on how you changed the whole circuit and added that tube would you?

I have to read up on tubes...i have no idea what they are used for but I do know they cost quite a bit and have to be replaced every no and then.

[RaceDriver205]

Yeah, how on earth do you "tube" a MXR distortion + ?

[Mark Hammer]

That looks...well, dangerous.  You should probably increase the size and scope of the "cage" for that tube.  At the very least, screw on some sort of extend lip underneath the tube so that accidentally placing weight on the front end of the box doesn't make it use the tube as a pivot-point.  I'm thinking here or a flat plate that would overlie the bottom of the chassis, and be secured via the regular bottomplate screws, but stick out and inch or two underneath the tube.

Ambitious, though.

[dano12]

Brad has been very generous in posting information about his tube projects, including the Dist+.

Check out his site:

http://lustfund.livejournal.com/

[markm]

That there Dist+ is impressive! 

[aron]

Something like your typical tube shield (but stronger) would work as well. Good Job!

[gloryboy]

Here is the BIG question: How does it sound? Is it running at a higher voltage now, or still 9v?

Cool mod job for sure though!

[RaceDriver205]

I dont get it, dont tubes need high voltages, like 100V+  ?

[petemoore]

I dont get it, dont tubes need high voltages, like 100V+  ?

12ax7's can be run "Starved Plate" down to lower voltages like 12vdc.

[brad]

There are no triodes or starved plates involved.

Follow the link Dano posted, scroll down to "The White Elephant", and all will be revealed   

[RaceDriver205]

Could you record a sound clip? We all want to hear how it sounds