been a while, thought i'd post something new...

[amptramp]

Hi pinkjimi, good to hear from you again!

Got a question about your revised schematic, R4 and the snarl pot seem to be just hanging out in the breeze there.  Since there is only one connection, it acts as an antenna.  The layout seems to confirm this.  Does it have any effect?

[pinkjimiphoton]

box hell... i hear ya gary!!! hey... cross country, which coast? you closer now or farther away?
i'm still in ct.... my girl found us a perfect house, i have  a huge workshop area... was lucky, had a wall-long work bench when i arrived.
but it took me since may to get set up and shuffle stuff around... then i had a couple huge boxes of components fall on the floor and OF COURSE go EVERYWHERE.... so i abandoned it for a long time.. lol... i had too many gigs come across my bench, i had layers of sheets and blankets on top of other layers of projects. finally got thru that.
so now i have my work area, an area carved out to set up my recording gear again, and storage for my guitar collection which grew from 20 to over 60 in the last year (despite me giving several away).

glad to see you back too bro

now.... can someone please knacker this bloody thing together on a breadboard please so i can assume it's verified?
i would really appreciate it... one of the two or three things i've learned over the downtime is
NEVER trust what i think is good until i've played it thru several REAL amps.
petey was right way back when he offered me some wicked helpful constructive criticism. a dano hodad is NOT the amp to test thru... everything tends to sound good (distortion wise) with it.

so now first thing i try is thru my kustom 200... if THAT sounds good, i run it thru an old boss rack preamp into the kustom... if that sounds ok, both clean and dirty, i assume it's ok.... but still try it thru my little peavey tube dealio, and my vox nite train and kustom 65 darts. final step is an old "american 5" style tube table radio. if it sounds ok thru all of the above, then i will live with it.

i had to re-voice probably 10 or 12 fuzzes since i moved, including the old toneblaster project which is finally legit.

so many circuits... so little time

[pinkjimiphoton]

Hi pinkjimi, good to hear from you again!

Got a question about your revised schematic, R4 and the snarl pot seem to be just hanging out in the breeze there.  Since there is only one connection, it acts as an antenna.  The layout seems to confirm this.  Does it have any effect?

nope, not an antennae

i can't do the math.... but if ya divide 100k by 39k, that's the value pot that seems to work the best.  cuz only the cap connects to ground, it works as a cheezy hi cut filter.

i just looked it up.... ya get a value of 28057.553956834534  or for all intents a 30 k pot. i didn't have one of them. closest i have is 10 and 50k.
this is all experimental on the breadboard kinda thing, so i tend to keep pecking away until i hear something i like. in this case, the combo of resistor cap and pot just worked out.

there's probably a better way to do it, i'm sure there is, but we're talking 10,000 monkeys here

[digi2t]

Well come back bro!! Missed you around here. 

[GGBB]

Got a question about your revised schematic, R4 and the snarl pot seem to be just hanging out in the breeze there.  Since there is only one connection, it acts as an antenna.  The layout seems to confirm this.  Does it have any effect?

only the cap connects to ground, it works as a cheezy hi cut filter.

Nice to see you back Jimi.

I'm confused by that snarl control too. Is it possible that the drawings are wrong and the cap connects from snarl 1 to ground? That would make it work something like you describe - changing the high end gain and rolloff (I think). Also, I don't see the 1u cap connected to the snarl pot anywhere on your layout (there are 7 caps total on your layout and 8 on the schematic).

[stallik]

Good to see you back man

[pinkjimiphoton]

dino~
thanks brother, missed you too. was great hearing from you earlier.


i really think you guys are gonna be surprised. it's almost like a guitar synth with the saturation and snarl all the way down,
it kinda "swells" in an octave... very soft and thick. you can mimic cellos and saxomophones and stuff on the neck pickemup if ya got hamburgers  on a lays poll.

hamburgers = autocorrected humbuckers

the more i play with it, the better i like it. it's..... different. video it when i can. peace!

[pinkjimiphoton]

Got a question about your revised schematic, R4 and the snarl pot seem to be just hanging out in the breeze there.  Since there is only one connection, it acts as an antenna.  The layout seems to confirm this.  Does it have any effect?

only the cap connects to ground, it works as a cheezy hi cut filter.

Nice to see you back Jimi.

I'm confused by that snarl control too. Is it possible that the drawings are wrong and the cap connects from snarl 1 to ground? That would make it work something like you describe - changing the high end gain and rolloff (I think). Also, I don't see the 1u cap connected to the snarl pot anywhere on your layout (there are 7 caps total on your layout and 8 on the schematic).

aha! yep! forgot the cap on my layout. will fix it shortly.

3, `1, your guess is as good as mine. it connects like i showed it, only one side of the snarl pot is connected to the cap, and that same side connects the 3.9k resistor and wiper. the snarl pot is being used as a variable resistor, not a potentiometer. like i said, it's weird. let me fix that layout, brb

[pinkjimiphoton]

here's the layout with the cap added back in. note: acts COMPLETELY different when the comp switch is off and on.
EVERYTHING is interactive.



if the snarl control works backwards... it may... simply reverse the connections to pins one and three.

also... duh, dumb dumb dumb.... snarl pot is 50k, not 100. my bad. don't know why i thought it was 100, didn't notice til i stuck it in a  box.
sorry for any confusion

[GGBB]

Another clarification needed: C4 on the layout = .001u and C7 on the schematic = 0.1u - they are the same cap - which is the correct value? If it's .001u then being in parallel with the 0.47u cap it isn't necessary as it's about a 2% change in total capacitance.

[pinkjimiphoton]

Another clarification needed: C4 on the layout = .001u and C7 on the schematic = 0.1u - they are the same cap - which is the correct value? If it's .001u then being in parallel with the 0.47u cap it isn't necessary as it's about a 2% change in total capacitance.

now i'm all confused.

i think the confusion is that jubal81 didn't follow the same numbering as i did.  what i call c4 and 5 are a .001 and a .47 cap in parallel. the circuit acts sounds and feels different with just the 470n cap.

on the schematic, that's another mistake... the caps should be .001 and .47, not .1 and .47.
i'll try and fix that schem real quick.

btw, the 50k snarl pot with the 3.9k resistor works out to like... 3.6178107606679037  3.6 k pot? a 5k may work instead. i did the math wrong earlier again.

doing the math, the 470 and 1 n caps = 471. maybe the acid kicked in. i'd imagine .47u is fine. a switch tho between them, or a panpot, may be even better tho.... another idea, another fuzz. ya can't put EVERYTHING in EVERY box.

here's the updated schematic. i didn't pull the .001 cap off, it's total mojo    magick, you know... 

[GGBB]

btw, the 50k snarl pot with the 3.9k resistor works out to like... 3.6178107606679037  3.6 k pot? a 5k may work instead. i did the math wrong earlier again.

Doing the 3k9||50k thing though makes for a strong log taper curve - most of the change occurs in the final 5% of the turn. A 5k linear pot would have a completely different responsiveness - 5k log would be a lot closer but still not there.

[pinkjimiphoton]

i actually understood that. thanks, gord!

i THiMk everything is straight now, except the size of the snarl pot being 50k instead of 100. ooops...

i can't ammend the diylc file unfortunately... for some reason, windows 7 only allows like ONE layer of undo.

[GGBB]

Back in August I bought a house and moved too, so I have not had any work space since (will probably be a while since the wife wants lots of reno work) and haven't done much pedal-wise for almost a year. So since I was really bored today and dying to do some pedal stuff, here's a preliminary PCB layout for the etchers - I'll get the final fancier version with transfer up later tonight. Visual verifications would be appreciated.



I left snarl lug 1 unconnected just in case - would be best to tie it to lug 2.

EDIT: Part numbers match Jimi's layout not the schematic. Not sure about Q2 AC176 pinout - be careful.

[Jdansti]

Glad to have you back Jimi!  I've got to get one of those colon scopes soon. Tried the thumb trick but didn't get very far. 

[pinkjimiphoton]

Back in August I bought a house and moved too, so I have not had any work space since (will probably be a while since the wife wants lots of reno work) and haven't done much pedal-wise for almost a year. So since I was really bored today and dying to do some pedal stuff, here's a preliminary PCB layout for the etchers - I'll get the final fancier version with transfer up later tonight. Visual verifications would be appreciated.



I left snarl lug 1 unconnected just in case - would be best to tie it to lug 2.

EDIT: Part numbers match Jimi's layout not the schematic. Not sure about Q2 AC176 pinout - be careful.

close... first thing i noticed is the saturate pot you have wired as a pot, but it's only the top and middle lugs being used in my layout/build/hand drawn schematic. i DID try it like you have it and it doesn't work the same. it's gotta be a variable resistor.

the ac176 pinout is marked with a tab to c. tough call, in this case, the ge reads the same either way, so if it sounds farty one way, turn it 180 degrees i guess. the layout matches what i built. i believe.  

you know how THAT goes.

Tried the thumb trick but didn't get very far.  

hi john.


http://instantrimshot.com/classic


edit: looking at it, the only thing i think i see is the 1u cap i used was an electro,  the + side would be to the left in case anyone builds it and doesn't have any caps that big that aren't electrolytic. other than that.... at a third look.... LOOKS GOOD!

[amptramp]

Still see a problem.  What causes current to flow through R4 or the snarl pot?  If the pot has an effect, it is because the actual circuit is different from the design.

[digi2t]

Still see a problem.  What causes current to flow through R4 or the snarl pot?  If the pot has an effect, it is because the actual circuit is different from the design.

Me thinks that lug 1 should go to ground, no? Maybe an oversight on the drawing?

[Ripdivot]

Still see a problem.  What causes current to flow through R4 or the snarl pot?  If the pot has an effect, it is because the actual circuit is different from the design.

Me thinks that lug 1 should go to ground, no? Maybe an oversight on the drawing?

I agree, as the schematic is drawn the snarl pot won't do anything.

[GGBB]

close... first thing i noticed is the saturate pot you have wired as a pot, but it's only the top and middle lugs being used in my layout/build/hand drawn schematic. i DID try it like you have it and it doesn't work the same. it's gotta be a variable resistor.

It is wired as a variable resistor except I connected lugs 1 & 2 together so that if the pot wiper fails you still have the pot working at max value rather than an open circuit.

edit: looking at it, the only thing i think i see is the 1u cap i used was an electro,  the + side would be to the left in case anyone builds it and doesn't have any caps that big that aren't electrolytic. other than that.... at a third look.... LOOKS GOOD!

Good point - I put a film there with plenty of room around it since they are getting more common now at 1uF. I'll mark the polarity on the final version.

EDIT:

the ac176 pinout is marked with a tab to c. tough call, in this case, the ge reads the same either way, so if it sounds farty one way, turn it 180 degrees i guess. the layout matches what i built. i believe.

I put extra pads there so it can easily be flipped.