Increasing gain inside a fuzz pedal (DAM Meathead)

[ironman180]

Hi guys!

I've built a few DAM Meathead clones using this vero layout


I love the sound but the only thing I'd like to change is adding more gain. Can someone point me in the right direction? What components should I switch so I can get more gain? I've already experimented with different transistors (never switched 2n3904 I only switched BC182 for BC184 and BC549) and I get really similar results.

Thank you all for help!

P.S. Would it be possible to add gain control using trim pot?

[antonis]

What components should I switch so I can get more gain?

Higher power supply..

Or delete 120k feedback bias resistor and place a 470k, or so, resistor between Q1 B & C (parallel with 470pF cap)

[PRR]

R2 R3 divide-down the too-hot signal. If not too hot for you, vary the ratio without changing the total (much).

[iainpunk]

R2 R3 divide-down the too-hot signal. If not too hot for you, vary the ratio without changing the total (much).

i'd say go with R2 being 4k7 and R3 deleted (shorted out) and then add clipping diodes for more distortion.
something like this:


cheers

[ironman180]

What components should I switch so I can get more gain?

Higher power supply..

Or delete 120k feedback bias resistor and place a 470k, or so, resistor between Q1 B & C (parallel with 470pF cap)

I'll try that, it seems like an easy thing to do. Thanks! 

[ironman180]

R2 R3 divide-down the too-hot signal. If not too hot for you, vary the ratio without changing the total (much).

Hmmm I'll put some pins where those resistors should go and I'll try to switch values a bit. Thank you!

[ironman180]

R2 R3 divide-down the too-hot signal. If not too hot for you, vary the ratio without changing the total (much).

i'd say go with R2 being 4k7 and R3 deleted (shorted out) and then add clipping diodes for more distortion.
something like this:


cheers

Thanks for your advice! It's just that I'm new to this stuff and have only basic knowledge of electronics... I know what diodes I should use for clipping but have no idea where to put them in Meathead circuit. Can you give me some guidelines for that, it would be much appreciated! Thanks! 

[iainpunk]

like this?

cheers, Iain

[R.G.]

It's worth remembering that gain is not distortion, nor sustain. "High gain" pedals may use gain to get more distortion or sustain, but it's only one piece of the puzzle.

[Elijah-Baley]

I've already experimented with different transistors (never switched 2n3904 I only switched BC182 for BC184 and BC549) and I get really similar results.
[...]

I breadboard this right a few of days ago, and I expected more gain. Using a MPSA18 to replace the 2N3904 helps, a bit. But I almost abandon it until I tried it with the humbuckers. It's all another story. What's your guitar?

You can increase the input cap, if you like it. It will give you more low end, and I think more signal, so more aggressive tone.

[ironman180]

like this?

cheers, Iain

I'll try this, thanks a lot!!!

[ironman180]

I've already experimented with different transistors (never switched 2n3904 I only switched BC182 for BC184 and BC549) and I get really similar results.
[...]

I breadboard this right a few of days ago, and I expected more gain. Using a MPSA18 to replace the 2N3904 helps, a bit. But I almost abandon it until I tried it with the humbuckers. It's all another story. What's your guitar?

You can increase the input cap, if you like it. It will give you more low end, and I think more signal, so more aggressive tone.

I have Yamaha Pacifica 311H with Dimarzio Super Distortion in bridge position so I don't think pickup is the issue 
Yeah I was thinking about increasing it, maybe that'll help a bit...

[ThermionicScott]

R2 R3 divide-down the too-hot signal. If not too hot for you, vary the ratio without changing the total (much).

i'd say go with R2 being 4k7 and R3 deleted (shorted out) and then add clipping diodes for more distortion.
something like this:


cheers

I'd never delved into the Muff Fuzz before, but that's a neat way to make use of all that extra level that just gets divided away in the Fuzz Face! 

Does the diode clipping make transistor selection a little less critical?

[ironman180]

like this?

cheers, Iain

I used your image to make a different layout, I put pin sockets in place of transistors because I couldn't align transistor images with sockets in veroboard in DIYLC and I changed input cap from 10nf to 47nf (I believe that is the input cap because it's connected to the input LOL). Would this work?

[PRR]

...... Does the diode clipping make transistor selection a little less critical?

IMHO, it makes it a very different effect. Without as much overdrive dynamic as a FF.

[iainpunk]

...... Does the diode clipping make transistor selection a little less critical?

IMHO, it makes it a very different effect. Without as much overdrive dynamic as a FF.

the DAM meathead has a status and a cult following in the doom and sludge metal community for being a massive wall of fuzz, i think that diodes would definitely add to that vibe.

in my experimentation i found little difference between random npn transistors in my stash

I used your image to make a different layout, I put pin sockets in place of transistors because I couldn't align transistor images with sockets in veroboard in DIYLC and I changed input cap from 10nf to 47nf (I believe that is the input cap because it's connected to the input LOL). Would this work?

that layout looks good!
you might also want to use sockets for the diodes so you can experiment with them as well as the transistors.

cheers

[ironman180]

...... Does the diode clipping make transistor selection a little less critical?

IMHO, it makes it a very different effect. Without as much overdrive dynamic as a FF.

the DAM meathead has a status and a cult following in the doom and sludge metal community for being a massive wall of fuzz, i think that diodes would definitely add to that vibe.

in my experimentation i found little difference between random npn transistors in my stash

I used your image to make a different layout, I put pin sockets in place of transistors because I couldn't align transistor images with sockets in veroboard in DIYLC and I changed input cap from 10nf to 47nf (I believe that is the input cap because it's connected to the input LOL). Would this work?

that layout looks good!
you might also want to use sockets for the diodes so you can experiment with them as well as the transistors.

cheers

Thanks a lot man!!!
Yeah, I'll probably add sockets for input cap too and experiment with that.