mxr dist plus clone

[the_alt_rocker]

hi I'm a newbie to the diy pedal scene but I just wanted to say that i'm building an mxr distortion plus based pedal and I want more gain , less treble and more bass so it can be more suited to being a stand alone distortion pedal.

What caps do you recommend for the bass and treble issue
What diodes silicon or germainuim
Should I change the resistor in the distortion circuit      layout here      [url http://www.tonepad.com/getFile.asp?id=11]

Thanks the_alt_rocker  

[Mark Hammer]

If you are looking at the "Mas Distortion" layout, changing R6 to 3k3 from 4k7 ups the max gain from 214 to 304 for a bit more push.  Increasing C4 from .047uf to .22uf -.47uf will retain bass at highest drive and squeeze more mileage out of the gain.  Placing a 47pf cap in parallel with R8 will lop some of the harsh treble off, and increasing C7 from .001uf to 2200-3300pf will help that along for a smoother tone that will still give you bite without sending you running for the amp controls when you hit the stompswitch.

[the_alt_rocker]

so 3k3 for r6
.022 for c4
47pf for c5
2200pf for c7

thank you

[Mark Hammer]

That should work.

[MikeH]

I believe that would be 0.22uf for c4, not 0.022uf

[zombiwoof]

As far as less treble goes, if you're building the pedal from scratch, why not just put a tone control on it, so you can dial in whatever amount of treble you want?.  You might find that with some amps you might need the extra high end.

Al

[Mark Hammer]

I believe that would be 0.22uf for c4, not 0.022uf

Yup.  Too quick on the "post" button.   

[the_alt_rocker]

As far as less treble goes, if you're building the pedal from scratch, why not just put a tone control on it, so you can dial in whatever amount of treble you want?.  You might find that with some amps you might need the extra high end.

Al

it's a ready made tonepad ciruit board so I cant

[Ned Flanger]

I just finished a modified Dist+ read the thread below.  Mark Hammer gave me great suggestions and I am very happy with the pedal.  Plenty of Distortion.  One think I did find out is that the 4558 can handle the distortion better than a 1458.

http://www.diystompboxes.com/smfforum/index.php?topic=20253.0

[Mark Hammer]

As far as less treble goes, if you're building the pedal from scratch, why not just put a tone control on it, so you can dial in whatever amount of treble you want?.  You might find that with some amps you might need the extra high end.

Al

it's a ready made tonepad ciruit board so I cant

That's where you are wrong.  The Stupidly Wonderful Tone Control (SWTC) is made for just such an occasion.  http://www.muzique.com/lab/swtc.htm  It can be easily inserted as a pot between the output of the board and the volume control.

[zombiwoof]

As far as less treble goes, if you're building the pedal from scratch, why not just put a tone control on it, so you can dial in whatever amount of treble you want?.  You might find that with some amps you might need the extra high end.

Al

it's a ready made tonepad ciruit board so I cant

That's where you are wrong.  The Stupidly Wonderful Tone Control (SWTC) is made for just such an occasion.  http://www.muzique.com/lab/swtc.htm  It can be easily inserted as a pot between the output of the board and the volume control.

Exactly the kind of thing I was thinking of!

Al

[the_alt_rocker]

I also want to put an LED in can I??

[Mark Hammer]

Yes, as long as you have the right switch.  If you want to completely bypass the circuit, when not in use, then you need a double-pole (two sets of contacts) double-throw (two different alternate settings) switch.  If you want to switch an LED on and off as well, then you need a triple-pole double-throw switch.

Note that some people report an audible clicking sound when they switch an LED on and off.  This occurs as a result of the LED suddenly demanding current in order to be turned on.  It is possible to eliminate this by choosing an LED of relatively high brightness, and using a higher value resistor to limit the current going to the LED.  We can nurse you through it once you get there.  In the meantime, plan around a starting resistor value of 2k2.

[the_alt_rocker]

what my resistor in the circuit should be a 2k2 then

[Mark Hammer]

The 2k2 resistor referred to would be the one between the +9v connection and the LED.  It has to be more than zero ohms or else the LED burns out.  If it's too big it only lets a teeny bit of current through, and the LED won't light up bright enough to be seen.  The suggested value of 2k2 is enough to let most LEDs light up, though ome will light up more than others with that value.  That's why I say "start with".  I like to use "superbright" LEDs, which need much less current to achieve the same brightness as "garden variety" ones.  There, I can get away with as much as 15k-18k.  In other instances, a small green normal LED against a light background may need a resistor value as low as 1k to make it bright enough to see.

[the_alt_rocker]

I just like an led that urns on and off with the effect so I'll need a TPDT swicth right? As it's a tonepad pcb where will I find the space to put an led and ac plug(which I didn't mention) on my crybaby the in and out jacks are mounted onto the pcb itself but the tonepad just uses one wire and one hole. Same with an ac plug?

[Mark Hammer]

Personally, I just run one lead from the LED to the switch, and the other lead to ground.  Then I run the resistor in question from a V+ pad/source somewhere on the copper side of the board to the other contact on the switch.

One of the reasons why I like to have some 1/8W resistors around is because you can easily solder them to a switch and slip a piece of heat-shrink tubing over the resistor and switch contact.

Note that if you use the same approach as me, the LED lead goes to the middle lug of the 3rd set of contacts, and the resistor goes to the spare lug on the effect side of the switch (i.e., not the bypass side where you have a straight wire connecting the two lugs).  You don't HAVE to do it that way, but it sure makes life easier.