MXR distortion +

[tube man in a kilt]

so being the know-it-all newbie i was, i jumped headlong into an overly complicated project first time around and i ended up giving up and now im selling off the parts i will never ever use. *sigh* but now i am ready to live again (what?) i use an MXR distortion plus in my band and love the sound. my bandmates father has one so i use it ALL THE TIME when we gig. anyway, i want to build one of my own since it is a fairly simple project. i have the PCB and such from tonepad, any suggestions on mods?

[R.G.]

Just checking - you gave up on your first project because it was too complicated to finish, so you are now ready to go back and work on something simpler, but you want to to evaluate a batch of modifications different from the basic circuit before you have built anything that works.

Is that right?

[tube man in a kilt]

well, you see, i would like to incorperate the mods into the pcb so they are simply part of the pedal, so i guess not "mods" more like changes to original design (which is a - say it with me now- modification).

EDIT!!!

you know what RG, sry bout being a jerk like that, yes, i did get ahead of myself, that was stupid. in fact, i dont even know what transistor i need for the circuit. need help.

[spongebob]

You could try different clipping diodes (various LEDs, Germanium diodes, etc.) and switch between them with a rotary switch for example...

[tube man in a kilt]

thats what i meant, but what transistor should i use? (im a transistor newb, i know tubes well enough, but solid state confuses me)

[cd]

There are no transistors in a Distortion+.

[spongebob]

http://www.muzique.com/schem/mxrdist2.gif

You need an opamp for this circuit, no transistors! If you want it noisy, use the original 741 opamp, otherwise get a more modern opamp like the TL071 or NE5534 for example. Use a socket for the opamp on the PCB and you can swap them later on...

[Fret Wire]

Before you get going, decide what you like about the Dist. + sound.? What things don't you like about it's sound? What doesn't it do that you'd like it to do?

Once you decide what you want the pedal to do, you can incorporate any mods right into your build from the start. You want an organized game plan before you even pick up the soldering iron.

The Dist. + does not use transistors, but an operational amplifier. The little square black thing with spider legs coming from it. You'll see terms IC, OA, chip, etc. You can use a 741 or TLO71 for your's.

[tube man in a kilt]

ya, general guitar gadget has a nice parts list, and they say you can use LM741 or JRC741 or LF351 IC's, but are there other options and what are the effects? i love the fact that the dist plus sounds like my old tube 4 track overdriven to the point of unpleasentness then compressed, i guess thats the only way i can describe it. idk, the trebly but not tinny sound is nice. so what are my options as far as IC's and diodes go?

EDIT
and what differance does it make if the two letters before the 741 are differant? should i just buy a bunch of differant ones and an IC socket and just toy around with differant ones?

[petemoore]

well if you build it for a single opamp and use a socket you can use any standard pinout SINGLE OPAMP> I CAN"T TYPE NUMBERS CUZ THIS PUTER IS PUKIN'> TL ZERO SEVEN ONE OR THE ABOVE MENTIONED FIVE FIVE THREE FOUR ARE GOOD?BETTER/BEST CHOICES DEPENDING ON YOUR PREFERENCE>
 I CAN RECOMMEND THE WARP OR SATURATION CONTROLS DEPICTED AT AMZ'S LAB NOTEBOOK>
 ONE N NINE ONE FOUR IS THE DIODE TYPE I'M USING ON THE DIST+  GE DIODES OR EVEN MOSFETS LEDS OR OTHER TYPES WORK BUT WITH DIFFERING OUTPuT LEVELS AND HARDNESS OF CLIPPING>I SOCKET THESE THINGS

[petemoore]

ADDING BOOSTER TO THE FRONT OF IT HAMMERS IT INTO A MORE DRIVEY SOUND. THERE ARE MYRIAD CHOICES FOR WHICH, FETZER VALVE I HAVE WITH MY DIST+ IN THE BOX< SIMpLE AND SOuNDS REALlY GOOD.
 I SAW YOU MENTIONED GE TRANSISTORS< IF YOU HAVE ONE WITH HFE OF SAY SIXTY OR A HUNDRED AND LOW LeaKAGE< A RANGEMASTER OR VOX TREBLe BOOSTER WITH SOCKETTED INPuT CAp MIGHT BE TO YOUR LiKING< AND WILL puT YOUR FF's NEARER TO [VERY NEAR TO] TONEBENDER SOUNDS.

[Fret Wire]

The numbers in the front are pretty much who made them. LM741=National, JRC741=NJM, UA741=TI. It's the numbers after that really matter, they describe the package. You want a DIP-8 pin. Any correct 741 will basically sound the same. The TLO71 will sound different.
There are plenty of diode options to swap. You could use a switch, but that's extra wiring to go wrong, and you've already had one build go to the scrap heap. Use sockets for the diodes, that way you can still switch them.
Back to what RG was saying, you kind of got the cart before the horse.

more/less bass
more/less treble
more/less gain (distortion)
different type of gain (clipping diodes)
more output (volume)
switchable options

These are what people tend to change. Once again, what do you want that Dist.+ to do. Describe your goals and it will be easy to recommend changes. Getting one running is the first step.

[Fret Wire]

Hey Pete, did you accidentally hold down your shift key, or one of the other keys too long while typing? I did that a couple of times before, and got the same problem. I couldn't figure out how to get back to the keyboard default settings, so I just reistalled the keyboard software.

[tube man in a kilt]

wait, you can socket diodes? or should i just breadboard this and buy the options that sound good?

[Fret Wire]

You can socket diodes, transistors, resistors, capacitors, IC's. For diodes, resistors, and caps, use the strip sockets, and break off the length needed.

[tube man in a kilt]

where would one find the sockets for these diodes?

[cd]

Are you going to be building more FX in the future?  If not, just buy a used Distortion+ and mod that.

[petemoore]

MOST ANY ELECTRONICS OUTLET INCLUDING RADIO SHACK WILL HAVE SOCKETS
 FOR THE OA USE AN EIGHT PIN IC SOCKET
 I ALSO LiKE TO GET THE LONG ONES WITH THE SOLID pINS< FOR CAPS OR SINGLe RoW SoCKETTING.
  USE OF SOCKET FOR IC pREVENTS IC THeRMAl DAMAGE, I ALWAYS USE SoCKET FoR IC/oA.

[nightingale]

fret wire~
i admire your willingness to help out a newbie.. IMO that is what makes this forum different than alot of other intenet stops that i make..

i lack the abilitly to explain things in a simple way like you..

[R.G.]

My point was this: if you're having trouble getting started, don't trip yourself up with a lot of modification options. It's like putting tank traps all over your back yard, then going out to play touch football.

You get two things out of building your own effect. One is the resulting effect. Frankly, I consider that the leftover garbage of the second thing, which is the increase in your own skill and understanding.

I strongly advise you to build the plain vanilla version first, then start messing with it. Better yet, build two plain vanilla ones, then mod one to see how much the same/different they are. When the first one runs, you then have a base of understanding and experience to go to the fancy stuff.

If you incorporate a lot of mods, you muddy up the inevitable mess you have when the first one doesn't work, and you make it harder for people here that want to help you to figure out whether it's the basic build or the mods that have you messed up.

Believe it or not, that really is friendly advice.