#1
ok, so i recently got a rocket pedals flexdrive, so my d.+ is now a very lacking pedal. so for me to keep it on my pedal board, i am wanting to perform some modifications to it, to help change up the tone and generally improve it.

1. to match the output of the channel when clean, my output knob needs to be at 1 o-clock (at least). how do i increase the output to it?

2. when maxed out, the distortion sounds like a bad clone of a green day song. is there a way to smooth out the distortion to give it a more saturated tube feel?

3. it seems to either scoop out the bass (or add to the treble). how do i boost the bass slightly?

thanks for the help in advance
#3
Quote by GS LEAD 5
1) Why do you want to do that? Just leave it at one oclock. Doesnt do anyone any harm.
2) No.
3) Does the pedal have mid/bass/treble knobs? USE THEM.

If it doesnt, buy a new pedal.

What amp do you have?


Dude, the first thing he said is he got a new pedal. And obviously, you don't know what a D+ is; only output and drive knobs. You offered no help at all.

On topic:

http://www.premierguitar.com/magazine/issue/2008/Dec/MXR_Distortion_Plus_Mods.aspx

Check out that one. If I remember correctly, it contains instructions to wire a tone pot.

EDIT: Using an EQ pedal after the distortion can help in clearing up the sound with no soldering required. You don't really need to boost the output, the pot is there to control the volume.
Quote by durhamdynamo
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Last edited by diamanth at Mar 17, 2011,
#4
The Dist+ is kind of a weak pedal to begin with... You can read some of Wamplers books and there are a few mods in there for them. You can change component values and whatnot but its a pretty simple circuit anyway. I'd just leave it and buy something better. Go all out and build yourself a Dr. Boogie.
#5
You can add a "Big Muff Tone Stack" to it. I don't remember how I did it on mine exactly but I did it on mine once. It comes after the volume knob. Also, I don't remember the science behind it, but a flaw of the design in that pedal is that as you increase the gain it increases the high end. You can try rounding out the harshness by running a small capacitor in series with one of the clipping diodes. 400 picofarads I think is a small enough starting point. Someone may correct me though.
#6
Quote by diamanth
Dude, the first thing he said is he got a new pedal. And obviously, you don't know what a D+ is; only output and drive knobs. You offered no help at all.

On topic:

http://www.premierguitar.com/magazine/issue/2008/Dec/MXR_Distortion_Plus_Mods.aspx

Check out that one. If I remember correctly, it contains instructions to wire a tone pot.

EDIT: Using an EQ pedal after the distortion can help in clearing up the sound with no soldering required. You don't really need to boost the output, the pot is there to control the volume.


thanks for the article that helped well. i think i'll be doing one or two of those mods. i love how simple the pedal is, but now i can get all the tones i like in that pedal, in my new one, so its time to try and find that warm tube-sound .


edit: i also found this article http://www.diystompboxes.com/pedals/mods.html which helped me as well.

and i'll try checking out that capacitor trick inkandlead.
#7
Quote by inkandlead
You can add a "Big Muff Tone Stack" to it. I don't remember how I did it on mine exactly but I did it on mine once. It comes after the volume knob. Also, I don't remember the science behind it, but a flaw of the design in that pedal is that as you increase the gain it increases the high end. You can try rounding out the harshness by running a small capacitor in series with one of the clipping diodes. 400 picofarads I think is a small enough starting point. Someone may correct me though.



Seems kind of odd to me. Most tone controls go BEFORE the volume control.
When I build a pedal with a tone stack its usually like:
Pedal Circuit > Tone Stack > Gain Recovery Stage (If needed) > Volume.

Not saying that that way is wrong, just different than most designs.
Last edited by CodeMonk at Mar 18, 2011,
#8
Quote by CodeMonk
Seems kind of odd to me. Most tone controls go BEFORE the volume control.
When I build a pedal with a tone stack its usually like:
Pedal Circuit > Tone Stack > Gain Recovery Stage (If needed) > Volume.

Not saying that that way is wrong, just different than most designs.


I could be wrong too. I did it a few years ago and I don't have the pedal anymore to check. I think I put it after because it was easier. It was one of the first mods I'd ever done so I was a bit uneducated on that stuff.
#9
If you experiment with the diodes, you can make it crunchier, have more fuzz, smoother, whatever you want. They used to have the germanium 1N270 diodes in the 70's, if you put those in place of the two stock ones, turn the Output knob all the way up and Distortion knob all the way down and put your Flexdrive after it on a mid-high gain distortion, you should be able to get Randy Rhoads tone. The Flexdrive seems to be a Plexi-ish distortion, it's advertised to get Malcom Young AC/DC tones up to Van Halen II. You should also be able to get good bluesy tones if you combine the two and mess with the knobs. Also, you could remove a diode to make it have a more tubey tone, or add one. But if you take one out, the gain is going to decrease. If you add one, the gain will increase. Look at the schematic at the link for some ideas, it has some suggestions for different diodes and other mods:
http://3.bp.blogspot.com/_1KIwZrxSy6A/S-ZcjF6uRaI/AAAAAAAAAeU/5k2LTErtfNE/s1600/mxr_distortion_plus.gif

Also look at this:
http://www.premierguitar.com/Magazine/Issue/2008/Dec/MXR_Distortion_Plus_Mods.aspx
Last edited by plexi123 at Mar 21, 2011,
#10
Quote by plexi123
If you experiment with the transistors, you can make it crunchier, have more fuzz, smoother, whatever you want. They used to have the germanium 1N270 transistors in the 70's, if you put those in place of the two stock ones, turn the Output knob all the way up and Distortion knob all the way down and put your Flexdrive after it on a mid-high gain distortion, you should be able to get Randy Rhoads tone. The Flexdrive seems to be a Plexi-ish distortion, it's advertised to get Malcom Young AC/DC tones up to Van Halen II. You should also be able to get good bluesy tones if you combine the two and mess with the knobs. Also, you could remove a transistor to make it have a more tubey tone, or add one. But if you take one out, the gain is going to decrease. If you add one, the gain will increase. Look at the schematic at the link for some ideas, it has some suggestions for different transistors and other mods:
http://3.bp.blogspot.com/_1KIwZrxSy6A/S-ZcjF6uRaI/AAAAAAAAAeU/5k2LTErtfNE/s1600/mxr_distortion_plus.gif

Also look at this:
http://www.premierguitar.com/Magazine/Issue/2008/Dec/MXR_Distortion_Plus_Mods.aspx


Do you mean diodes? There are no transistors in the Distortion+. I only ask so that nobody gets confused.
#11
Quote by inkandlead
Do you mean diodes? There are no transistors in the Distortion+. I only ask so that nobody gets confused.

Yeah, diodes. It's fixed now.
Last edited by plexi123 at Mar 21, 2011,
#12
actually there are several trasistors in the D+ (in the form of grown junctions on a silicon substrate inside a black plastic thing)

I built a NOS-spec D+ with original 1N270 diodes. It sounds great and is really fat. you can get close with 1N34As (or other Ge types), which are common. I haven't seen 1N270s anywhere. I think the modern D+ uses silicon. i also had a silicon version, and it barely clipped.
http://profile.ultimate-guitar.com/Invader+Jim/pictures/gear/748872/915937

the most dramatic mods involve changing clipping diodes. Ge is fat, silicon gives more volume and lighter clipping. people also like LEDs. everyone raves about the internal protection diodes of MOSFET transistors. they are supposedly the most natural and tube-like. hell you could even try the base-emitter junction of regular bipolar transistors.

you can also mess with the resistors in the feedback loop (particularly the 1M resistor across pins 2 and 6 of the IC). higher values=more distortion (of the op-amp itself; the diodes will clamp the output voltage [volume] to a fixed level unless you remove them).
#13
thanks for all this information everyone. now i can move onto how exactly i'm going to mod it.


one last question though, what diode would you recommend (and where) to get a slightly more mellow tone? i want to build from there, and see if i want anything else done.


thanks for all the info again everyone.