reducing Fuzz Face volume without changing tone...

Started by MetalGod, May 30, 2007, 05:48:22 PM

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MetalGod

ok, so I've got a great sounding Fuzz Face and it sounds best with the volume on full.  however, this is much louder than the bypassed effect and turning down the volume looses 'that' tone.

is there any way to reduce the volume without changing the tone?

:icon_cool:

Meanderthal

 I believe the RM Axis has a bleeder cap across the volume pot to address that issue. I'm not sure how well it works, never tried it.
I am not responsible for your imagination.

MetalGod

Quote from: Meanderthal on May 30, 2007, 06:15:39 PM
I believe the RM Axis has a bleeder cap across the volume pot to address that issue. I'm not sure how well it works, never tried it.

across the outside two lugs? - do you know the value?

oh, thanks btw (manners, whoops!)

;D

hendriko

the RM classic fuzz uses a 0.0022uF cap from lug 2 to 3 of a 47k pot
Gimme gimme shock treatment.

MetalGod

Quote from: hendriko on May 30, 2007, 06:48:48 PM
the RM classic fuzz uses a 0.0022uF cap from lug 2 to 3 of a 47k pot

do you mean that the cap is connected across the two outer lugs on the pot (i.e. not conected to the wiper?

OR

do you mean that the cap is connected between the 'top' (i.e. non-grounded side of the pot) and the wiper?

8)

tcobretti

I really don't think that cap will affect the overall volume of the pedal, just the EQ.

I believe the answer to your original question is no.  The FF circuit's EQing changes based on the position/value of the volume pot (which is weird but true), and part of the tone you like is no doubt caused by the cranked pedal's interaction with your amplifier.  So, lowering the volume of the pedal will change the things that make it sound good to you.

hendriko

^^its connected to the wiper (2) and lug 3
check the FAQ for which lugs im talking about ;)
Gimme gimme shock treatment.

mac

Just an idea... what about fixing the 100 or 500k volume pot and replacing the 470R with a 500R pot a la rangemaster volume?
Or make the 0.01uf cap variable? When you lower the volume some resistance is on the signal path changing the RC corner freq.

Anyway, I think as said above, maybe with the volume maxed what you are hearing is the FF signal being loud enough to make the amp's preamp "distort" as well.

mac
mac@mac-pc:~$ sudo apt install ECC83 EL84

petemoore

  FF is part of the equation, I don't know the rest.
  IF there's output tubes, they can change the character of the distortion when pushed..
  If not the speaker also can change the character of the distortion.
  So since I don't know much, it's perhaps possible to modify the FF to suit your needs better, but if the amp/speaker are 'having a say' FF circuit mods may not be able to get 'that' at a lower volume without...
  Reducing the volume after the amp and speaker are set for tone. Putting a shirt on the speaker can warm it up...lol...that's what I've been doing and it rolls off treble 'first'...but allows the amp/speaker to do 'that' what it does when cranked up a bit more.
Convention creates following, following creates convention.

MarcoMike

what about boosting the "bypassed" signal? if it is true bypass it should be quite easy... just chose a clean booster and squeeze it in! you may use a trimmer to set the "clean" volume closer to the distorted one...
Only those who attempt the absurd will achieve the impossible.

petemoore

  See the latest addition to 'additions to the FAQ'.
Convention creates following, following creates convention.

Roobin

What are you using for a vol pot? I'm using a 100k, and having the same problem...might try a 500k one instead.

petemoore

#12
 
  When turned CW/full, the 500k may leave a bit more highs and more output through, shunting less overall signal to ground [than a 100k from signal path to ground would], because the pot wafer resistance is always between SP and ground.
  However, with 500k @ at 50% setting, you now have a large resistance in the signal path, this may shave a bit more highs than you want, this can be compensated or overcompensated for by place a bypass cap across the SP lugs of the volume pot.
 
and of course a 100k for the same output would be set higher, so less resistance in the SP would be present, perhaps preserving the highs at the settings you use.
  I like 50k - 100k for FF VC value, shaving off the 'excess' highs with a small cap across the 1k [1k instead of 470ohm for higher output] see Axis Face.
Convention creates following, following creates convention.

Roobin

QuoteHowever, with 500k @ at 50% setting, you now have a large resistance in the signal path, this may shave a bit more highs than you want, this can be compensated or overcompensated for by place a bypass cap across the SP lugs of the volume pot.
  and of course a 100k for the same output would be set higher, so less resistance in the SP would be present, perhaps preserving the highs at the settings you use.

That's what I was thinking - and of course, you could mess around with pot values as well, as well as adding reistors - although this might change the filtering.

trevize

I changed the 500k volume pot with a 100k and now it sounds perfect!

MetalGod

thanks for all the suggestions, I was hoping there would be an easy 'known' mod but unfortunately not.

I'm using a 100k vol pot as it sounds perfect for me - 500k is much too bassy.  I tried reducing the 1k resistor to 470ohms but it changed the tone too much.  Gonna try a voltage divider before the vol pot and see if dumping some signal to ground works - I suppose a resistor in the 220k range might pad the output down too.  lotsa stuff to try.

8)

Gus

MetalGod

   You have asked a HARD question to answer.   It seems simple but it might not be.  There are some good ideas in the posts above.

First you need to figure out what the tone change you like at max ff volume is caused by (the hard part)

This involves figuring out the gain staging in the tube amp the model number and name might help.  what type speaker(s) in the cab open back or closed back

  When the volume of the FF is full you are driving all the stages harder some amps do more preamp distortion others PI other output stage then the mix of stages then blocking distotion

Then you got the speaker distortion and you ear distorts at loud levels

Two things you might try
a speaker brake with the fuzz at full or a very clean booster before the amp to try to detect what you like with the max FF vol.

It could also be you like the min series resistance to the input of the amp that you get with the volume at full.  read the TS pages at geofex the output buffer part.

Do tests one at a time write notes

Or if you are advanced enought use a EF buffer with the emitter offset to maybe  5.5V with a 9v supply to start after the vol control as a test to try.  this takes the series resistance part of the volume pot to the input of the amp part out.  Maybe a 10K emitter R and a MPSA18.  If you are clever you can use a lin pot and use the input r of the bias resistors and transistor (look at the geofex writeup on pots)

Sometimes it is hard to figure out how to get the same tone at a lower level for live.  Recording and iso boxes are some other "fixes"

I would guess it is the amp and speaker being driven hard

MetalGod

Quote from: Gus on June 01, 2007, 06:54:08 PM
MetalGod

   You have asked a HARD question to answer.   It seems simple but it might not be.  There are some good ideas in the posts above.

First you need to figure out what the tone change you like at max ff volume is caused by (the hard part)

This involves figuring out the gain staging in the tube amp the model number and name might help.  what type speaker(s) in the cab open back or closed back

  When the volume of the FF is full you are driving all the stages harder some amps do more preamp distortion others PI other output stage then the mix of stages then blocking distotion

Then you got the speaker distortion and you ear distorts at loud levels

Two things you might try
a speaker brake with the fuzz at full or a very clean booster before the amp to try to detect what you like with the max FF vol.

It could also be you like the min series resistance to the input of the amp that you get with the volume at full.  read the TS pages at geofex the output buffer part.

Do tests one at a time write notes

Or if you are advanced enought use a EF buffer with the emitter offset to maybe  5.5V with a 9v supply to start after the vol control as a test to try.  this takes the series resistance part of the volume pot to the input of the amp part out.  Maybe a 10K emitter R and a MPSA18.  If you are clever you can use a lin pot and use the input r of the bias resistors and transistor (look at the geofex writeup on pots)

Sometimes it is hard to figure out how to get the same tone at a lower level for live.  Recording and iso boxes are some other "fixes"

I would guess it is the amp and speaker being driven hard

Gus, the FF sounds best on full volume with the amp at any volume - I've tried it with my '76 Superbass, the clean channel on my 5150 and a friend's HotRod Deluxe.  I don't think it's that the FF is driving the input harder, it's more of an EQ and purity of the tone why I like it on full volume.

I'll try the EF idea - why do you sugest setting up the EF with 5.5v on the emitter?

also, I've been looking at the 4ms Fuzz Jade Schem (basically a tweaked FF) and the volume pot has the output taken from the 'top' of the pot rather than the wiper - is this just a taper thing or can you think of any other reason to do this?

lastly, looking at BJT configurations I've been wondering if anyone has used the common base config for fuzz pedal use???

Cheers!

8)