MXR Distortion + vero build

[petemoore]

  Max gain is set with gainpot resistance of 0.0ohms.
  50k is what I used, it focuses the range of gain to high/max, allowing more precise control over a much smaller range of settings.
  Losing all the medium-high through minimum gain [as covered by a 1meg gainpot] was no loss at all, these circuits shine [I build DOD250 / Dist+] at high gain/clipping distortion.
  For lower gain boosts I choose other circuits entirely.

[LonePhantom]

Thanks all. I'll check this stuff out.

Any pointers on the clipping diode switch question?

Cheers

[arma61]

Thanks all. I'll check this stuff out.

Any pointers on the clipping diode switch question?

Cheers

here you go m8

http://www.diystompboxes.com/smfforum/index.php?topic=64578.msg510288#msg510288

[LonePhantom]

Thanks all. I'll check this stuff out.

Any pointers on the clipping diode switch question?

Cheers

here you go m8

http://www.diystompboxes.com/smfforum/index.php?topic=64578.msg510288#msg510288

Fantastic, thanks!

So I just leave two of the holes empty, and all is well?

I've even got a DPDT switch sitting on my work bench at home that was going to be used for a guitar pickup mod. I might just use it for this pedal for now, and get another one later.

Cheers

[LonePhantom]

Ahh, just realised that I was using a linear 1meg pot, that is probably my main issue. Not sure why I had that written down on my parts list. I dare say I'll get a much better taper from the logarithmic.

[LonePhantom]

Just another question as well. Can you use other op amps like a 4558 type chip with this?

Cheers

[deadastronaut]

nope!..

the 741 has a different pinout to the 4558...

google images is your friend...

[LonePhantom]

OK then.

It looks to me that the TL071 is a direct swap. Will it provide less noise, better clarity?

[rousejeremy]

OK then.

It looks to me that the TL071 is a direct swap. Will it provide less noise, better clarity?

Do you mean TLO72?

[LonePhantom]

I was looking at both the 71 & 72. I might have mixed up the two. So would it be a good substitute for sound quality or different tones.

[g-sus]

OK then.

It looks to me that the TL071 is a direct swap. Will it provide less noise, better clarity?

I used TL071 in one of my builds. I would say better clarity but more trebly/harsh..I prefer the original 741.

[LonePhantom]

Thanks for that. I don't like the trebly/harsh thought so I might stick with the 741 then.

Cheers

[LonePhantom]

I wired in my DPDT switch tonight with great success. Thanks again all for your help. This is a fantastic forum.

Next I'm going to have a play with some of the caps and resistors to see what tonal changes I can get.

[petemoore]

  I used to race them, still do.
  Have 2 fine DIST+/250 circuits I use.
  I considered the build fun, and the reliability doubled. Built the second one so I could know more about what I wanted to change exactly on the first one.
  Second one set up for all the 'stuff'...
  4k7 made easily piggybacked by having increased lead protrusion above the board.
  .047uf installed as a socketted item, and or: .047uf + .047uf when the mod-switch works, defaulting to .047uf value when the switch breaks.
  I chose assymetric/symmetric, then later built it as assymetric only [with option to be symmetric with 1 box opening 1 solder/lift of a 1 Ge diode end.
  BTB si diodes with 1 Ge diode across them also = Si/Ge diode clipping [the Si in same direction as Ge doesn't do anything until the Ge gets off it's back.
  After trying 27 Dist+/OD250/Blue Clipper/etc. and all applicable mods...907 times, I managed to build to very reliable [so far fine] 1 DOD250 [a couple weeks ago] to restore the sound without having to debug my DIST+ that literally got 1/2 baked in 2003...kinda survived...has glitchy switch'n troubles...got replaced by the new 250 with all shiny insides [no singe marks or smoke stains].
  Kinda proud of it because I built it with some mods in it/on it [treble control], and have been able to 'just use it' instead of the back and forth between the 29 mods....907 times/different ways.
  I got down to mostly the voicing and the diode assymetric clipping for me, then when the gain needs more I boost [compress w/Orange Squeezer] the input.
  The only '1 more time adjustments' I do relate to changes in volume / amp, quickly, after that the only thing I adjust is the bypass switch mode [on or off].

[LonePhantom]

Cool.

I'm planning on building a DOD 250 as well, just to see what the differences are like.

I also bought some germanium diodes from here to try out too. 

[LonePhantom]

Just a quick question for you.

I'm doing some mods found on here:
http://www.premierguitar.com/Magazine/Issue/2008/Dec/MXR_Distortion_Plus_Mods.aspx

I'm looking at the tone control mod listed where it states "Change C5 to a .0022uf and wired in series with a 1m audio taper pot to act as a tone control."

I just want to confirm if the .001uf cap I'm working from is the one situated above the trace cut to the left of the diodes on the vero layout on page 1 of this thread?

Also, how do I connect the 1meg pot to connect successfully with the rest of the circuit? I still don't quite understand the schematics.

Thanks in advance.

[arma61]

I just want to confirm if the .001uf cap I'm working from is the one situated above the trace cut to the left of the diodes on the vero layout on page 1 of this thread?

Yes, that's the one

Also, how do I connect the 1meg pot to connect successfully with the rest of the circuit? I still don't quite understand the schematics.

Thanks in advance.

I suggest you try first the new value in place of the old one and see how do you like it.

Then if you want to add the pot tone disconnect the bottom side of that cap (column 10, row 3)) , and connect it to one of the outer lug of the new pot, then connect the center lug and the other outher lug to ground, that's it !

Ciao

[LonePhantom]

Thanks heaps. I'll try that today. So is ground the main ground where the jacks and stuff connect, or the hole left from where the cap originally connected?

Cheers

[arma61]

ground is ground, all ground points must be connected together, so that hole should be ok

[LonePhantom]

awesome, thanks again. I'm learning bit by bit with these builds.