crackle NOT okay

[markm]

replace the output to ground 100k resistor with a 50k volume pot - replace the "crackle ok" pot with a 5k internal trimpot to set gain

this would completly eradicate the crackle.

im not sure why zvex put the crackle in there at all? then again, some people seem to think the crackle is a good thing..

cheers
ulysses

The original "mixing console" circuit crackled and it was....well,......Okay. 

[A.S.P.]

replace the output to ground 100k resistor with a 50k volume pot - replace the "crackle ok" pot with a 5k internal trimpot to set gain

this would completly eradicate the crackle.

im not sure why zvex put the crackle in there at all? then again, some people seem to think the crackle is a good thing..

cheers
ulysses

he wanted to be able to set the gain, not the output volume.

[ulysses]

he wanted to be able to set the gain, not the output volume.

strange that he would make it possible to set the gain and then go on to recommend that you leave the gain at maximum all the time..

anyway.. it think its better with a trimpot for gain and knob for volume.. or both knobs if you are inclined that way..

cheers
ulysses

[markm]

he wanted to be able to set the gain, not the output volume.

strange that he would make it possible to set the gain and then go on to recommend that you leave the gain at maximum all the time..

anyway.. it think its better with a trimpot for gain and knob for volume.. or both knobs if you are inclined that way..

cheers
ulysses

....or, one could preset the gain to be wide open and just use a master volume.

[A.S.P.]

he wanted to be able to set the gain, not the output volume.

strange that he would make it possible to set the gain and then go on to recommend that you leave the gain at maximum all the time..

anyway.. it think its better with a trimpot for gain and knob for volume.. or both knobs if you are inclined that way..

cheers
ulysses

re-read replies #50, 52 & 53;
at the same time the volume gets controlled, and such saves 1 extra knob

[ulysses]

re-read replies #50, 52 & 53;
at the same time the volume gets controlled, and such saves 1 extra knob

hmm.. im not sure what you are getting at here.. i reread the posts that you asked me to.. is it about saving a knob?

if you want it not to crackle, then you can use a volume knob as i suggested and use a trim pot for the gain (or even a resistor if you wanted it perm. set)

i built it with 2 knobs becasue i wanted to have the high guitar signal gain while at the same time not have it blow my amp to bits and deafen my neighbors..

i think it sounds best with the gain about half way.. i can then control the volume seperatly..

if the signal tone does change with the increased gain, then this is another reason to have a seperate volume knob - you dont want to have to go deaf to get the tone of the maxxed out gain..

i like the two knobs and i like not having to have "crackle" while the amp is turned up really loud.. i cant see "crackle" being a good thing at a gig..

cheers
ulysses

[remmelt]

Turn the pedal off before adjusting the knobs? It won't crackle because it's true bypass. I don't see the problem, even live.

[markm]

I like the crackle. 

[Paul Marossy]

he wanted to be able to set the gain, not the output volume.

That's the way I've always seen it. As long as it doesn't snap and pop, too, I think it will all be OK. 

[markm]

I still like thae crackle! 

[jonathan perez]

i like the two knobs and i like not having to have "crackle" while the amp is turned up really loud.. i cant see "crackle" being a good thing at a gig.

i think the crackle would only be a problem during a gig if, during the half hour pause between songs, to make it seem as if youre not just dicking around with pedals, you were twisting the knob so much that the crackle begins to irritate the front row and those with the bottles of lite beer in the back.

i always use it as a lead boost. i taped the knob down so that it doesnt move, at all! problem solved, no crackle, but even if it did, it would be okay, because it would be brief...since the crowd had just been pummeled with intense thrash metal to begin with, i think they can handle a couple seconds of crackle. 

[blanik]

...since the crowd had just been pummeled with intense thrash metal to begin with, i think they can handle a couple seconds of crackle. 

hell, they won't even ear it... 

[Paul Marossy]

hell, they won't even ear it...

Yeah, they'll be too busy carrying on. 

[jonathan perez]

very good. 

[newbie builder]

At least on mine, the crackle is very soft- I don't think many people would notice too much of it.

[WGTP]

There have been hints, that other things are changing besides the gain.  The impedance and symmertry of the distortion are a couple of important parameters.  Probably others I don't understand.   

[Stratomaster]

Had to bring this one back from the dead... I've never had a thread I started go to 4 pages!  Ok now to the questions...

I used a J201 in place of the BS170 in the circuit--just out of curiousity.  It sounds even better now!  But am I hurting anything?  Was it just a fluke that it worked?  Either way, I hope it's not dying on the inside because it sounds amazing.  I can get tube sounding overdrive by cranking it and having my amp barely audible.  I thought MOSFETs and J-FETs couldn't be used interchangably.  Any explanation would help!

[Isaiah]

I'm interested in hearing answers on JFET/MOSFET inter-changability too please

[stm]

N-channel JFETs and MOSFETs are both voltage-controlled devices.  The JFET requires a negative gate voltage to turn it OFF, while the MOSFET needs a positive gate voltage to turn it ON...   the previous sentence means that in both devices you get more conduction (or lower D-S resistance, or higher drain current) as the gate voltage goes more positive (-1V is more positive than -2V).  So, both devices are controlled by a voltage and voltage direction is the same (however there is an implied offset).

If you replace a MOSFET in a self biased JFET circuit like the Fetzer Valve it won't work, since gate voltage will be zero, keeping the MOSFET shutdown.  On the other hand, if you replace a JFET in a MOSFET circuit that has voltage divider bias it will still work, however the operating point will be a little different depending on the characteristics of the MOSFET and JFET.  This is the case when you replace a JFET in the SHO.

Finally, a JFET tends to color the sound more with 2nd harmonic, and considering your bias might be a little off-center, the new sound you are hearing is the addition of even harmonics and asymmetric clipping to the mix.  In the reight amounts these add richness to the sound.

[jonathan perez]

interesting. thank you!