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DIY Stompboxes => Building your own stompbox => Topic started by: Pigyboy on April 17, 2011, 09:10:25 AM

Title: Turn down gain - Highs go away
Post by: Pigyboy on April 17, 2011, 09:10:25 AM
Is there a way to keep the high frequencies falling off when rolling back the gain on a fuzz face type circuit?
Cheers,
Chris
Title: Re: Turn down gain - Highs go away
Post by: vendettav on April 17, 2011, 09:36:20 AM
if it's like a pre circuit gain pot acting like gutiar's volume know than look up treble bleed for volume pot. that'll get you going
Title: Re: Turn down gain - Highs go away
Post by: Mark Hammer on April 17, 2011, 12:11:26 PM
Quote from: Pigyboy on April 17, 2011, 09:10:25 AM
Is there a way to keep the high frequencies falling off when rolling back the gain on a fuzz face type circuit?
Cheers,
Chris
Yeah, use another fuzz circuit.

I don't mean to be snarky, but let's get real, here.  The Fuzz Face doesn't lose highs as you turn gain down, it adds them as the gain gets turned up.  It's a bit like asking if there is a way to keep the intensity of the flavour in one's chili as you remove hot peppers from the batch you cook.

I'll wait a few seconds while you smack your forehead, mutter "D'oh!!", and regain your composure.

Okay, you can go back to soldering and rocking now. :icon_biggrin:
Title: Re: Turn down gain - Highs go away
Post by: Pigyboy on April 19, 2011, 09:02:03 AM
Sorry for the slow response. Just got back from NOFX in Madrid and my ears are still ringing.  :icon_mrgreen:
Thanks Mark. I never considered your point of the highs being added so I guess I will live with what I have though I will poke around treble bleed idea to see if there are any interesting sonic combinations to be had.
Cheers
Title: Re: Turn down gain - Highs go away
Post by: Mark Hammer on April 19, 2011, 09:56:03 AM
Incidentally, setting aside for the moment that the FF is a different sort of circuit, it is often a good idea to roll off highs on the input stages in a distortiondevice, so that the harmonics added most are the lower-order harmonics.  Producing harmonics of harmonics, especially if they are upper harmonics, is what we might normally call "fizz": something that many players strive to eliminate from their tone.

Of course, the consequence of that sort of pre-compensation is that when you set such a circuit for more modest distortion, it can seem duller because you're hearing more of the intentional dullness.

One way around that, though its feasibility depends on the specific circuit, is to adjust the treble content of the driving signal, such that at higher drive settings, there is more treble rolloff prior to clipping, with treble restored as gain is turned down. I tried to do that on The Crank, though I imagine many other designs do that too.
Title: Re: Turn down gain - Highs go away
Post by: thegnu on April 19, 2011, 10:23:33 AM
Quote from: Pigyboy on April 19, 2011, 09:02:03 AM
Sorry for the slow response. Just got back from NOFX in Madrid and my ears are still ringing.  :icon_mrgreen:

wear the earplugs, my brother.  we don't need any more deaf musicians.  :)

http://www.etymotic.com/ephp/er20.html

EDIT: and to actually address the question, people like the fuzz face because they can roll the volume off on their guitar to clean up the signal a bit.  experiment with this, perhaps.  which is in line with what mark is saying about the pre-compensation.
Title: Re: Turn down gain - Highs go away
Post by: Paul Marossy on April 19, 2011, 11:18:55 AM
Quote from: vendettav on April 17, 2011, 09:36:20 AM
if it's like a pre circuit gain pot acting like gutiar's volume know than look up treble bleed for volume pot. that'll get you going

Depending on circuit topology, in my experience, that can actually work pretty well.
Title: Re: Turn down gain - Highs go away
Post by: bancika on April 19, 2011, 11:23:20 AM
I love the way kinman style treble bleed works. Resistor and cap in series, I think 130K and 1n or something like that.
Cheers
Title: Re: Turn down gain - Highs go away
Post by: Pigyboy on April 19, 2011, 02:22:38 PM
Quote from: thegnu on April 19, 2011, 10:23:33 AM
Quote from: Pigyboy on April 19, 2011, 09:02:03 AM
Sorry for the slow response. Just got back from NOFX in Madrid and my ears are still ringing.  :icon_mrgreen:

wear the earplugs, my brother.  we don't need any more deaf musicians.  :)


I did have my ear plugs in :icon_eek:

I am trying some of the treble bleed ideas. I have been playing around with pulling two signals from different locations of the circuit and feeding them into different value pots and into a master volume so it creates a kind of moving emphasis of the assymetrical clipping and the controls are interactive. It is like the maestro fuzz. I like the defined sustain and 'wobble' variability of the distortion and want to be able to retain (or add) a bit of emphasis to the high frequencies with the gain backed off. 
Thanks for the help,
Chris