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

[pinkjimiphoton]

i freekin love you guys

so.... where the hell do i get a couple boards made? or should i take the plunge and try and etch myself?
gord's board looks killer....

gonna try and do a vero up i guess.

i've let a couple friends try it now, they were really amazed at some of the tricks it does,  but they liked the "meat and potatoes" stuff, too.

i hope if you guys build this, you enjoy it.

gil... no resistor, big pop, right? i hope i put it in the right spot lol

[garcho]

You can get a minimum order of 3 made at a reasonable price from OSH Park. Gotta have Eagle CAD style Gerber files, though...

EagleCAD ain't that bad, it's not the best schematic maker but it's such a breeze to do layouts, you'll laugh maniacally. Good for having boards fab'd or home etch. You don't need to buy the software to do medium to small boards.

Etch yourself, PLUNGE!!!!!!!!!

I know you know, just a little push:
http://smallbear-electronics.mybigcommerce.com/pc-board-making-kit-press-n-peel/
http://smallbear-electronics.mybigcommerce.com/pc-board-making-kit-positive-photo-process/

[GGBB]

Great job Jimi - sounds great and the mystery is revealed. Only one small detail to point out - the "bottom" lug of the snarl pot you call pin #3 is actually pin #1 - only mentioning it for the sake of accuracy.

Here's the revised layout and PCB (300dpi) - I've added a volume control, LED resistor and pad, and pads to jumper the remaining pin either to pin #2 or to ground, or go out to a switch and 1M resistor for the synth/fuzz option :





EDIT: board size is 2.2x1.6"

I've updated it again to add the optional 1M resistor and switch for the synth/fuzz option.

[pinkjimiphoton]

You can get a minimum order of 3 made at a reasonable price from OSH Park. Gotta have Eagle CAD style Gerber files, though...

EagleCAD ain't that bad, it's not the best schematic maker but it's such a breeze to do layouts, you'll laugh maniacally. Good for having boards fab'd or home etch. You don't need to buy the software to do medium to small boards.

Etch yourself, PLUNGE!!!!!!!!!

I know you know, just a little push:
http://smallbear-electronics.mybigcommerce.com/pc-board-making-kit-press-n-peel/
http://smallbear-electronics.mybigcommerce.com/pc-board-making-kit-positive-photo-process/

we gotta lazer printer, isn't there a way to do it with that?
thanks for the links, i'll take a peek... right now tho a little above my paygrade i think.

i DO wanna take the plunge tho. if i could etch my own, i could build literally anything.

[pinkjimiphoton]

Great job Jimi - sounds great and the mystery is revealed. Only one small detail to point out - the "bottom" lug of the snarl pot you call pin #3 is actually pin #1 - only mentioning it for the sake of accuracy.

Here's the revised layout and PCB (300dpi) - I've added a volume control, LED resistor and pad, and pads to jumper the remaining pin either to pin #2 or to ground, or go out to a switch and 1M resistor for the synth/fuzz option :





EDIT: board size is 2.2x1.6"

I've updated it again to add the optional 1M resistor and switch for the synth/fuzz option.

wow, gord, that looks AWESOME... thanks so much!!!!

i'm gonna see about getting maybe 10 of these made up (with your permission of course) to give to friends.
i'm slowly dragging more diy'ers into fuzzboxmakethry

[Jdansti]

I've looked around, but can't find AC176s other than Ebay, which I'm not sure I trust. Can anyone steer me in the right direction for finding any, or should I substitute a different transistor?

Edit: How about NTE103A?

[digi2t]

I've looked around, but can't find AC176s other than Ebay, which I'm not sure I trust. Can anyone steer me in the right direction for finding any, or should I substitute a different transistor?

Edit: How about NTE103A?

Russian GT404 should do ya. Just choose the right suffix letter for the desired gain.
"А" and "B" are 30-80 range.
"Б" and "Г" are 60-150 range.

English letter translation;
Russian - English
   A            A
   Б            B
   B            V
   Г            G

They're either 25v or 40v versions, so either of a particular group will do.

[pinkjimiphoton]

don't bother with nte crap, it's allllllllways garbage. i used to buy them 123's for way too much money at my local electronic shop. the worst ge's i ever tried.

ac187's will work, some of the japanese ones, like dino said, the russian ones. the important thing is more the gain range i'd imagine. but i did try several 176's and they all worked pretty good. the russian ones i had left were good too, but just a little less bite to them.

i buy 'em on ebay, i'll try and see if the guys i go 'em from before still have 'em. i got some from the ukraine, some from germany, they were all good. the only bunk ones i got were from some american guys unfortunately... and ya still gotta buy 'em 10 or more at a time usually to get a couple good ones.

but the bad ones usually make great clippers still, especially paired with an led. yummy!

i let my friend dave try this and the mk 2 juergulator today, and he freaked right the f*ck out... the strings sound especially.

the new juerg is still in process, but i got the prototype going tonite, boxed and all... but that's another story

anyways, john, if ya get stuck pm me and i'll snail mail ya one

dino... thanks for the translation info!! way cool and VERY helpful!

fwiw... i imagine a silicon of the proper gain would work, too... ya may have to mess with the biasing some tho to get it to sing.

[Jdansti]

Thanks Digi and Jimi. Your info should get me going.

Edit: Just bought some GT404A from a guy in Ukraine. Thanks for your help!

[GGBB]

i'm gonna see about getting maybe 10 of these made up (with your permission of course) to give to friends.

Not a problem Jimi - go for it. But you might want to test one first before making a batch.

[GGBB]

i DO wanna take the plunge tho. if i could etch my own, i could build literally anything.

In my experience - etching a board is easy.  The hard part is getting the toner transfer right.  Press-n-peel blue paper would probably be the easiest way around that but I haven't tried it so I don't know.  Etching can be greatly simplified by using the sponge technique - just a tablespoon or two of ferric chloride in a small piece of sponge rubbed over the board (use gloves and don't splash) for 5 minutes and you're done.  Might take longer if there's a lot of copper to remove so ground fills are helpful.  Toss out the sponge and gloves when done - no need for keeping a big tub of etchant around for a bath.

[pinkjimiphoton]

that seems like a good way to do that, actually. but my girl would probably kill me

+1 on trying one first. if i pull it off, i'll try making a sheet of acid sounding monstrosities... lol...

i need to save my pittance and research a little... i DO have a lazer jet printer, which i guess is good

[mykaitch]

I was bored so I drew it too. Found the errors you guys fixed.
In the second 'fixed' drawing you lost the ground on tyhe snarl pot.
C4 is pointless (across 470n its nothing)
Make c6 10-100n
Hate D3 - put it in series
A couple of BC337 will work fine
You could use 1N4148 for D1/D2 which are germanium in the orig. The clip point will raise to 0.7.
I'd try it without C4/C5 (ie short out)
With R8 there will always be some degree of clipping esp with germ diodes
I don't really think the compress switch does, it just makes the clipping hard.
If you replace c5/5 with a 1k and the diodes with blue leds they will light when clipping at about 2v4 - other colour leds light/clip
at lower volts. Just done this to my pre-amp to stop front end saturation.
I would wire the jacks to switch the battery on/off
Nice one!
I am building a compressor soon and may play around with this then.

[pinkjimiphoton]

I was bored so I drew it too. Found the errors you guys fixed.

apparently not

In the second 'fixed' drawing you lost the ground on tyhe snarl pot.

that's cuz the only ground on the snarl pot is thru the cap.  the pot should not be grounded, tho you CAN ground it... that makes it more fuzzy, but it loses the "synthy" sound.[/quote]

C4 is pointless (across 470n its nothing)

hey!! thats total MOJO, man... lol 
the original circuit used the small cap, this started as a hack on something else... i doccumented what i built so if someone else wanted the same thing,
they could do it. that's ultimately why it's there.

Make c6 10-100n

you can do that but it's not gonna sound the same. not even remotely close at 10n.

Hate D3 - put it in series

series with what? it's part of the diode clipper, it's main use is to even out the response of the pots. clipping like that creates compression.

A couple of BC337 will work fine

as a fuzz, yes. but it won't do the synthy stuff. been there. tried it. did you read the thread?

You could use 1N4148 for D1/D2 which are germanium in the orig. The clip point will raise to 0.7.

yeah, tonally not much change, just a little louder and more compression.

I'd try it without C4/C5 (ie short out)

without c4 the entire response/ tone of the circuit would change. ommitting c5 will change the tone significantly, and make it more of a straight fuzz. it did not exist in the original circuit.

With R8 there will always be some degree of clipping esp with germ diodes

there's enough clipping already, but the main purpose of r8 is to stop the switch from popping when you ground the diodes. without it there is a substantial pop, with it, tonal difference is negligible. for it to really allow much clipping, it would need to be about a million times smaller... ie, 1-10k to really work as a "warp" control. 1 meg is big enough where it doesn't matter much. kinda like an anti pop anywhere else on a switch. if concerning, go bigger... 4.7-10meg.

I don't really think the compress switch does, it just makes the clipping hard.

and.... what happens when you hard clip a signal? it becomes compressed. in this case, it's use is to even out the sweep of the different pots when engaged... when off, some settings of knobs can have significantly different volumes.

If you replace c5/5 with a 1k and the diodes with blue leds they will light when clipping at about 2v4 - other colour leds light/clip
at lower volts. Just done this to my pre-amp to stop front end saturation.

totally different application... mictester used led and ge diodes in series. i don't want to stop ANY saturation on this. led's would make it louder, but i would lose the compression effect of the ge's and a little bit of the tone they offer. i don't know what ya mean by replace c5/5 with a 1k?

I would wire the jacks to switch the battery on/off

Nice one!
I am building a compressor soon and may play around with this then.
[/quote]

lol... that is pretty standard, but there's no switching or jacks shown, so i guess that one's moot bud.
i generally don't bother showing switching for input output... peeps can do that whatever way they like.

good luck with your compressor.

[pinkjimiphoton]

ps.. losing c5 also means no blocking cap to the output of the fuzz, so whatever voltage is used by q2 would be hitting the input of your amp...

not advised. you generally need to block dc mike, that's one of the reasons we use caps. shut door to dc, open door to ac (audio is ac).

peace

[mykaitch]

I was bored so I drew it too. Found the errors you guys fixed.

Just to clear the air - this ain't no flame war or see who's more clever etc, yeah? I'm interested in all kinda things so we just having a technical exchange .


apparently not   AKA Monty Python =  Yes I did

In the second 'fixed' drawing you lost the ground on tyhe snarl pot.

that's cuz the only ground on the snarl pot is thru the cap.  the pot should not be grounded, tho you CAN ground it... that makes it more fuzzy, but it loses the "synthy" sound.

See what you did there now .... across R4. 100K, bit endy, about 20k might feel better (IMHO)

C4 is pointless (across 470n its nothing)

hey!! thats total MOJO, man... lol   

Excuse me? Go calc 1n // with 470n BUT see your point about choose what you want. Mojo indeed. I wibble on your Mojo, but it is groovey.

Oh gord blimey - I took my numbers from the pic of the board... so in your diag I refer to C6/7

the original circuit used the small cap, this started as a hack on something else... i doccumented what i built so if someone else wanted the same thing,
they could do it. that's ultimately why it's there.  Ah, thats ok then

Make c6 10-100n

you can do that but it's not gonna sound the same. not even remotely close at 10n.

Unless I got the wrong part in MY drawing ... C6 is across the 100u C7 9v rail cap ?
No way can it change the sound.

See above ... in your diag it is C2  and the bad diode is D1 (on the board pic D3
D3 should be in series with the 9v as what we Brit chaps call an idiot diode. The way it is if you connect 9v wrong way you short out the supply - nasty. IF my diagram is numbered correctly...well it is

Hate D3 - put it in series

series with what? it's part of the diode clipper, it's main use is to even out the response of the pots. clipping like that creates compression.

A couple of BC337 will work fine

as a fuzz, yes. but it won't do the synthy stuff. been there. tried it. did you read the thread?

You could use 1N4148 for D1/D2 which are germanium in the orig. The clip point will raise to 0.7.

yeah, tonally not much change, just a little louder and more compression.

I'd try it without C4/C5 (ie short out)

without c4 the entire response/ tone of the circuit would change. ommitting c5 will change the tone significantly, and make it more of a straight fuzz. it did not exist in the original circuit.

With R8 there will always be some degree of clipping esp with germ diodes

there's enough clipping already, but the main purpose of r8 is to stop the switch from popping when you ground the diodes. without it there is a substantial pop, with it, tonal difference is negligible. for it to really allow much clipping, it would need to be about a million times smaller... ie, 1-10k to really work as a "warp" control. 1 meg is big enough where it doesn't matter much. kinda like an anti pop anywhere else on a switch. if concerning, go bigger... 4.7-10meg.

I don't really think the compress switch does, it just makes the clipping hard.

and.... what happens when you hard clip a signal? it becomes compressed. in this case, it's use is to even out the sweep of the different pots when engaged... when off, some settings of knobs can have significantly different volumes.

If you replace c5/5 with a 1k and the diodes with blue leds they will light when clipping at about 2v4 - other colour leds light/clip
at lower volts. Just done this to my pre-amp to stop front end saturation.

Compressors of which I have made many ...a bit like AGC...what should happen is that for a given variaible input there should be a constant level out. So low levels get increased ...well you know. No clipping happens. This is very useful when driving filters to separate the freqs for sound to light for example. Don't get mad, I'm just chatting with y'all, y'hear. I tell no lies man, when you come down to ma hood ah promise you a good time, man. Respect bro.
How come we gave you English and you messed it up ? (JOKE!!!!!)



totally different application... mictester used led and ge diodes in series. i don't want to stop ANY saturation on this. led's would make it louder, but i would lose the compression effect of the ge's and a little bit of the tone they offer. i don't know what ya mean by replace c5/5 with a 1k?

I would wire the jacks to switch the battery on/off

Nice one!
I am building a compressor soon and may play around with this then.
[/quote]

lol... that is pretty standard, but there's no switching or jacks shown, so i guess that one's moot bud.
i generally don't bother showing switching for input output... peeps can do that whatever way they like.

good luck with your compressor.
[/quote]

[pinkjimiphoton]

lol... that's harder to follow than a politician on a witness stand bro, lol...

no worries, no flame wars here. i'm an idiot and i know it, was just trying to explain why this funked-up thing
is the way it is mike... no worries!!

we don't speak the queen's english. hell, these days, we don't even speak AMERICAN english here.

yeah, i didn't label comp compressor... it just compresses the fuzz slightly as an added bonus. the main reason i did it was to just even out the response of the pots... otherwise, you'd get dramatic volume changes between settings, particularly the snarl and sat pots.

tried grounding the snarl pot, but then it becomes a potentiometer instead of just a variable resistance.. you can go whichever way ya choose on that. it's louder and brighter if not grounded, grounded it works like a traditional tone control more.
imho, this thing needs a bit of bite, it's kinda "round" sounding.

i tried it with all silicon... indeed, the original trannys were mpsa515 or something like that. stock was a kinda wimpy treble boosted fuzz that was nothing to write home about... a one knob fuzzface-ish kinda dealio. it will work for sure, but if ya got some nice old leaky ge it will do the strings thing better. it's a bit brassier with the si... like a lot brassier. i spent a good 5-6 hours pumping trannies (that sounds so sick) into the thing before i settled... so YMMV bro.

anyways... if i was a dick, my apologies. ever since the united states became team america, world police i've been a little off

[GGBB]

See what you did there now .... across R4. 100K, bit endy, about 20k might feel better (IMHO)

You can talk about what you *think/feel* might be better, but Jimi has a better approach - he experiments and finds the best values according to what he likes to *hear*. Did you build it yet?

Make c6 10-100n ... in your diag it is C2.

Yes - good catch - the schematic has a typo - it should be 100nF not 100pF.

and the bad diode is D1 (on the board pic D3 should be in series with the 9v as what we Brit chaps call an idiot diode. The way it is if you connect 9v wrong way you short out the supply - nasty.

The diode is not bad. Reverse polarity protection can be done either way. Each has their own merits and downfalls. The primary advantage with reverse parallel over series is that there is no voltage loss from the diode Vf. It's largely a matter of personal preference.

[pinkjimiphoton]

See what you did there now .... across R4. 100K, bit endy, about 20k might feel better (IMHO)

You can talk about what you *think/feel* might be better, but Jimi has a better approach - he experiments and finds the best values according to what he likes to *hear*. Did you build it yet?

Make c6 10-100n ... in your diag it is C2.

Yes - good catch - the schematic has a typo - it should be 100nF not 100pF.

and the bad diode is D1 (on the board pic D3 should be in series with the 9v as what we Brit chaps call an idiot diode. The way it is if you connect 9v wrong way you short out the supply - nasty.

the small non-electro in the power supply in parallel with the 100u cap indeed is 100p on mine, not 100n. you could go as big as ya need to, its just there to help with rfi.
The diode is not bad. Reverse polarity protection can be done either way. Each has their own merits and downfalls. The primary advantage with reverse parallel over series is that there is no voltage loss from the diode Vf. It's largely a matter of personal preference. i could see it needing 100n in some cases, but that's pretty @#$%in big!!

the diode i did like that to avoid the voltage drop of the other way... i've had issues with some things from time to time that don't seem to respond as well with a series diode. this way doesn't seem to affect the voltage or tone much if at all, but dropping the voltage can change it some. depends on the circuit.

i just wanted to present the thing as built by me.

btw... if 470n and 1n together in parallel = 471n total.... and that 1n doesn't matter.... why would pf caps matter whatsoever? they shouldn't be big enough to be significant, but take one out of a circuit and the tone can change a lot. so.... 471n may matter more, or less... beats me. but if a 100p cap can be significant, 1000p should be more significant, right?

[mykaitch]

btw... if 470n and 1n together in parallel = 471n total.... and that 1n doesn't matter.... why would pf caps matter whatsoever? they shouldn't be big enough to be significant, but take one out of a circuit and the tone can change a lot. so.... 471n may matter more, or less... beats me. but if a 100p cap can be significant, 1000p should be more significant, right? Wink

Had another look at the first sketch of the track layout and there are diff IDs to the sch.
As we say in the North here, anyroadup happen as a s not thar knows...

Suppose you have a really good 470n 1% cap ...so thats +- 4n7 ......but as you said,thats not what you mean so thats fine.
100p // 1000p ...well unless it is a real critical f issue, the 100p does nothing.
I totally agree with 'sod the rules' and see what does what. Many times I have had great results from something
that the math and the rules say is wrong.
As for idiot diode,you can always use a schottky...over here the series diode is the norm but hey,whatever
Back to me soldering iron