Simple DOD FX52 Classic Fuzz Mods?

[ck3]

I am a new member and hope that this thread has been posted in the correct subforum.   

I have found the ample output level, midrange hump, and distinctive crackle of this pedal to be most pleasing ... but often wish that it had a smidge more clarity and gain.  Is there a simple way to accomplish this?

[petemoore]

more clarity and gain.
  Starting with/without schematic.
  With schematic lends itself to discussion.
  Without schematic is likely a good way to get 'clarity / gain', gain for sure, adding a gain stage before it, a 1 transistor boost should be more than sufficient to gain and flexibility to your overall rig, enough to drive a nice 9v dirtbox into higher gain response, non-intrusive and fairly inexpensive...
  Thirdly it may be possible to raise the gain on the active in the classic fuzz, and some mileage may be achieved by replacing capacitors with capacitors, changing some voicing cap values will change response, whether this is an improvement may lead to a long road to find out, long way back.
  Some modern fuzzes come with board traces so close it prohibits most modding.
   

[jonathan perez]

you want more gain?

put an OD or rangemaster-style boost in front...

you want clarity?

turn the fuzz off. 

[george]

woulda thought 'clarity' was the last thing you'd want out of a fuzz ...

anyway increasing the gain would reduce the clarity no?

[ck3]

Thanks for the responses.   

Unfortunately, I do not have immediate access to a schematic.  However, I do know someone who may be able to provide one in the near future. 

I have goosed the FX52 with various overdrives, boosters, and a parametric eq.  The results have been mixed, and I would prefer a more permanent/consistent, hard-wired solution ... though I am a n(.)(.)b and may not be able to do much beyond "soldering by numbers."   

When I made reference to "more clarity", I was thinking about a slight increase in the pedal's gating and an alteration of the upper mid range of its EQ envelope.  I am aware that fuzzes have earned their name for a reason. 

Given the tonal similarities between the FX52 and the FX-50B and FX53, I would almost venture to guess that all three have a similar layout with very minor differences between the respective schematics.  I have all three pedals on hand and could provide gut shots if they would prove to be helpful. 

[Dragonfly]

FX52 Classic Fuzz schematic:

AC

[Dragonfly]

A couple thoughts.

removing the 120pF cap in between pins 1-2 of the LF353 might help add a bit more "bite", without sounding overly harsh...or just reducing the value to say, 47pF, may help. The one between pins 6-7 could be altered as well, if the effect wasnt enough

reducing the sixze of the 220k resistor (between LF353 pin 1 and the volume pot) could help give a bit more "push" as well...you'd need to experiment with different values...maybe 100k-ish ?


also, the .001uF cap to ground (next to the clipping diodes) could be reduced to give more bite....maybe 470pF ? this controls how much high end is "bled to ground", and helps "smooth out" the clipped diode sound.


just some basic ideas, which may or may not be helpful / useful.

AC

[petemoore]

  "Romantic about Boost"
1  What I like about BOOST
  It makes my sound real tight,
  Tell it 'your the only one'
  Gonna build another tonight...yeahh
{Fuzz whisperin' in my ear...boost me for the gain that you wanna hear.. and that's true...
that's what I like about boost!
2  What I like about boost
  ...Goes on and off just right
  When I'm askin' 'what's it do'
  I can turn it off and tell allright...yeah
  {Tubes whisperin' in my ear, gimme little boost, don't be in fear and thats true, that's what I like about boost.
  What I like about boost
  It makes my levels right
  When the sound gets too low
  Hit the boost.. it sounds just right...yeah.
  Boost whisperin' in my ear, I can bring the level to what you wanna hear, and that's true...that's what I like about boost.
 

[Mark Hammer]

Clarity AND gain?  That can only mean one thing: post-clip gain adjustment.

Well, actually, that can mean a few things, depending on what you mean by "gain" (and I do wish we could all agree on this one ).  If, by "gain", you mean simply more output, that's easy.  If you mean a capacity to be both louder and at the edge of distortion more easily, that's another thing.

You can certainly produce more output level from this thing by swapping the clipping diodes for LEDs or simply replacing each individual diode with two of the same.  While that will still permit clipping, and will raise the output level of the pedal considerably, it will result in LESS distortion, because the clipping threshold will have been raised.  That achieves your goal of more potential clarity, since the distortion won't kick in until your "Fuzz" control is turnd up higher, so more of the range will be clear, and "clear" won't necessarily mean quiet or low volume.  Note, however, that feeding an extremely hot somewhat distorted signal to an amp will still generate more distortion (and perhaps even better distortion to some ears) downstream.

If you want to keep all that sizzle from the pedal, but want to be able to get more volume when it is set for cleanish tones,, then the mod has to be made after the diodes.  Dragonfly is quite correct that one way would be to reduce the value of the 220k resistor in question, although I suspect you'd need to up the value of the .01uf cap a bit in order to hang onto all the bass.

Another way is to replace the 18k feedback resistor in the upper right hand corner between pins 6 and 7 with a larger value, like 22k, or maybe even 27k.  Thing is, that's gonna screw with the functioning of the tone control.  Perhaps in a good way.  Perhaps in a bad way.  I suppose you can always experiment and see.

[Dragonfly]

Clarity AND gain?  That can only mean one thing: post-clip gain adjustment.

Well, actually, that can mean a few things, depending on what you mean by "gain" (and I do wish we could all agree on this one ).  If, by "gain", you mean simply more output, that's easy.  If you mean a capacity to be both louder and at the edge of distortion more easily, that's another thing.

You can certainly produce more output level from this thing by swapping the clipping diodes for LEDs or simply replacing each individual diode with two of the same.  While that will still permit clipping, and will raise the output level of the pedal considerably, it will result in LESS distortion, because the clipping threshold will have been raised.  That achieves your goal of more potential clarity, since the distortion won't kick in until your "Fuzz" control is turnd up higher, so more of the range will be clear, and "clear" won't necessarily mean quiet or low volume.  Note, however, that feeding an extremely hot somewhat distorted signal to an amp will still generate more distortion (and perhaps even better distortion to some ears) downstream.

If you want to keep all that sizzle from the pedal, but want to be able to get more volume when it is set for cleanish tones,, then the mod has to be made after the diodes.  Dragonfly is quite correct that one way would be to reduce the value of the 220k resistor in question, although I suspect you'd need to up the value of the .01uf cap a bit in order to hang onto all the bass.

Another way is to replace the 18k feedback resistor in the upper right hand corner between pins 6 and 7 with a larger value, like 22k, or maybe even 27k.  Thing is, that's gonna screw with the functioning of the tone control.  Perhaps in a good way.  Perhaps in a bad way.  I suppose you can always experiment and see.

i'll "DITTO" what Mark mentioned, and add this...

In an earlier post i suggested the possibility of trying to remove or reduce the value of the 120pF caps ...i was thinking about it last night, and i would definitely only suggest "reducing" them a bit, not getting rid of them altogether. I suspect that they, as well as rolling of a bit of high end, help "stabilize" the LF353.

[Ronsonic]

"Clarity and gain" sounds to me like more drive (output level) and less fuzz. Something as simple as replacing one or both of the clipping diodes with two diodes, or LEDs could do that.

All depends on what's really wanted.

Ron

[Phorhas]

  "Romantic about Boost"
1  What I like about BOOST
  It makes my sound real tight,
  Tell it 'your the only one'
  Gonna build another tonight...yeahh
{Fuzz whisperin' in my ear...boost me for the gain that you wanna hear.. and that's true...
that's what I like about boost!
2  What I like about boost
  ...Goes on and off just right
  When I'm askin' 'what's it do'
  I can turn it off and tell allright...yeah
  {Tubes whisperin' in my ear, gimme little boost, don't be in fear and thats true, that's what I like about boost.
  What I like about boost
  It makes my levels right
  When the sound gets too low
  Hit the boost.. it sounds just right...yeah.
  Boost whisperin' in my ear, I can bring the level to what you wanna hear, and that's true...that's what I like about boost.
 

That was beautiful, man 

[jrc4558]

Also, you could replace the 1uF cap at the op-amp which has the fuzz control with a 0.1uf one... Try. this will cut the low end, but may bring 'clarity' to sound.

[george]

  "Romantic about Boost"
1  What I like about BOOST
  It makes my sound real tight,
  Tell it 'your the only one'
  Gonna build another tonight...yeahh
{Fuzz whisperin' in my ear...boost me for the gain that you wanna hear.. and that's true...
that's what I like about boost!
2  What I like about boost
  ...Goes on and off just right
  When I'm askin' 'what's it do'
  I can turn it off and tell allright...yeah
  {Tubes whisperin' in my ear, gimme little boost, don't be in fear and thats true, that's what I like about boost.
  What I like about boost
  It makes my levels right
  When the sound gets too low
  Hit the boost.. it sounds just right...yeah.
  Boost whisperin' in my ear, I can bring the level to what you wanna hear, and that's true...that's what I like about boost.
 

That was beautiful, man 

yeah you should sing more!