Need some help China fuzzface kit(AC128 )

Started by piankung, May 21, 2018, 07:24:06 AM

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piankung


Kevin Mitchell

We can't build a pedal for you. And your post has pretty much no context for anyone to help you out. I advise you do some research. The fuzz face is the most simple circuit out there. Any question you may have has likely been answered 100 times over on the internet.

If you're that hopeless post a picture of what you have so we may elaborate on some things to get the ball rolling.
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pinkjimiphoton

Quote from: piankung on May 21, 2018, 07:24:06 AM
I bought this from aliexpress, but i dont have any instruction to wiring jack/pot/switch

https://m.en.aliexpress.com/item/32840495281.html?trace=wwwdetail2mobilesitedetail&productId=32840495281&productSubject=Vintage-Fuzz-Face-DIY-guitar-Pedal-Kit-with-Germanium-AC128-Transistors-and-1590B-pre-drilled-enclosure

I already put R C and transistor to pcb but I cant do anything afterthat.

Need some help

yeah, be prepared for trouble with it. the way they do that circuit is as a pnp with a negative ground. nothing but hassles. i built the same for shits n giggles a while back and it drove me batshit crazy trying to get it to work. i finally gave up and wired it as a straight pnp fuzzface.

landtone1008 on ebay has the same kit, its probably protaitone as the vendor.

look on AMZ or use the search function here for pnp fuzzfaces with negative ground.

technically, it doesn't matter if its pnp or npn for the power supply wiring because "the transistors are isolated by caps" but i find it to be 90% true and 10% bullshit. why?

cuz when ya turn your guitar knob to off with a pedal wired this way, very often it will squeal with a horrible mating buffalo noise. i believe its from leakage of the transistors contaminating the ground plane, but hey, i did way too many drugs as a kid ;)

basically... hook your positive lead to ground, hook your negative lead to positive,  then ya go input and output wires.

the fuzz control will have one side grounded, the other to the board, and the wiper to the 22u cap.

the output is off the wiper <center> of the volume control.

adding led's etc can be problematic with this circuit, as can be trying to wire a power supply jack. the instructions they didn't include aren't much help. i will try and find 'em and scan 'em and up 'em for ya, but really, there's not much to the fuzzface circuit. just look at any fuzzface schematic and have at it.

hollah back if'n yer still stuck
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gpcustomguitars

#3
Hello!

I'm new here, found the thread by searching for the solution to the same problem. I usually build guitars, but I like to solder a bit too, so I bought this same kit, and it arrived yesterday.
All seems nice enough, but other than a list of components with their values, the kit lacks schematic or illustration on connecting off-board parts (in/out jack sockets, led, dc jack). I did ask the seller to send me the instructions or a pic of an assembled board. Will report if I get an response.

What I did figure out (I think ;) ):
Out jack should be straightforward, +=tip, -=ground. I think that the switch orientation is standard, holes oriented up-down.

What I still need to figure is what to do with those on / off pads marked on pcb, where to connect the led, battery and the ring tip of the in jack. I'm not sure I want to connect the dc in jack, there's no protection against wrong polarity I think, and in my limited experience, fuzzes tend to sound nicer battery powered.

Here's a pic of the PCB:

Any thoughts much appreciated, will post pics of the actual board later!

BR
Goran

gpcustomguitars

Just received some partial info from the seller:






I hope they will send some more info on mysterious (to me at least on/off pads)...

Ice-9

#5
Quote from: gpcustomguitars on May 30, 2018, 07:07:38 AM
Just received some partial info from the seller:






I hope they will send some more info on mysterious (to me at least on/off pads)...

At a glance at the PCB the on/off pads look like they are for two LEDS. ON will be pedal effect on and OFF would be effect off. Double check that to make sure but it looks like it to me from what I can make out of the pcb.
www.stanleyfx.co.uk

Sanity: doing the same thing over and over again and expecting the same result. Mick Taylor

Please at least have 1 forum post before sending me a PM demanding something.

duck_arse

#6
I'm almost certain we had a thread this year on that pcb for that circuit and the switch wiring - but there is NO WAY I am going to type "fuzz face china" into the search hole, let me tell you.

[edit :] no way known ...... https://www.diystompboxes.com/smfforum/index.php?topic=119292.msg1112473#msg1112473
don't make me draw another line.

pinkjimiphoton

yeah, this is the one i built too. total pain in the ass. turn the guitar down, and it oscillates like crazy.

the good news is you can fix it. yes, it had on and off state led's. its from protaitone, but is resold by unscrupulous vendors with no build docs or schem.

the supplied ac128's will melt in less than a second if overheated, so use sockets.

they wire the pnp fuzz with a negative ground like a boss pedal. fine, when it works. i found i have to stick 1000-2200uf of cap across the power supply rails to stop the oscillation.

it works if you're the guy with his guitar on 10 all the time. but not if you turn it down.

i just got up.... musician thing, i'm nocturnal nowadays. when i get down to my dungeon i will grab the pedal, and take some crappy phone shots and tell ya how to hook it up so it actually will work.
yes, keep it on the battery. it will sound better.
the led is problematic the way they reccomend if memory serves.


give me a couple hours and i'll hook ya up. its a great little kit for the price, 20 bux with free shipping for EVERYthing makes having missing build docs a big deal. you could ohm out all the connections with your beeper and figure it out, but...

gimme a little bit.
stay tuned....
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pinkjimiphoton

will up some pics asap

basically, with the board so the pots n q's are on top facing you

the right led pads are +/- for the led

the middle and right solder pads for the switch go to the middle n top of a  3pdt

jumper the two bottom outside pins of the 3pdt


input jack tip to center left of 3pdt, top left pin to board in

output jack tip to right center 3pdt top right pin to board in.

in/out top hole is signal, bottom hole earth on the board. run one of these grounds to the input jack sleeve

power jack

battery + to power jack batt pin

battery - power jack -

power jack - to input jack ring

input jack - hole top of board just to left of q2

input jack + to hole top left corner of board

i had to strap a 35v 2200uF cap across the power rails to get it to work stable

i'll up a drawing of the wiring shortly













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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

gpcustomguitars

Thanks a lot!!! I went trough the other thread, and tried to wire it like in the manual shown, but no :) LED lights up, but no sound, I do have signal when in bypass.
Your pics are different to what I did, will try to re-solder later today. A drawing would be much appreciated!!!
Can't tell did you replace R1 or R2 with trimpot?

I don't think I've managed to overheat the AC's, but I'll look up a way to test them. I happen to have a 3300uF I could use, would that be too much? I got a bunch of them recently for another project.

duck_arse

when bypassing a troublesome backwards wired fuzzface, as much as you can still might not be enough. try the 3300uF, it can't hurt, won't burn. [you can/should also sling a ceramic cap across the supply as well, 100nF is standard, but the value isn't critical.]
don't make me draw another line.

pinkjimiphoton

i had had to rework the damn board so much some of the traces failed, so i had to tack connections on point to point.

the setup as it is is a bloody mess on the board.

of course, mine, which WAS working died when i tried it last nite after opening it up. i gotta debug, but from the way its acting, i am assuming i shorted the damn transistors by hitting the case of the damn thing... the base is connected to the shield of the 404's, and i dunno. its annoying!!

i will scan the pic i drew yesterday when it was working and see if it works for ya. at this point, all bets are off ;)

the good news is i got the drawing in front of me, so i will scan it and up it in a couple minutes.
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

pinkjimiphoton

here ya go. this WAS working, soooo... hopefully it will help a little bit



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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

pinkjimiphoton

dudes, i an sofa king level dain bread sometimes.
i got it working. i wasn't paying attention when one of the wires broke off, where i marked for the output? no bueno for me. the bottom socket thing for the dpdt bypass switch weirdness? bottom layer on right is the output from the fuzz to the switch.
my sincere apologies for the mistake, hope it didn't cost you time or parts.

should be good to go other than that. seems to be working great again, so please, let me know how you guys make out. if we get it right i may send the vendor a build doc just to be a ....

anyways... hope this works out for ya'll peace
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

gpcustomguitars

Big thanks!!!!

I didn't change anything yet, had a acoustic repair to finish yesterday, but the most obvious mistake is that Chinese instructions show switch turned wrong...I'll rewire everything according to your drawing and report back.

The bottom left pad on the switch section of the pcb just connects to top left pin of the switch? (crossed off connection that says IN)? Also, it forks to -pad for the off LED, right?
Where did you choose to strap the 2200uF?

I'll definitely omit the dc jack (and use it for something else :) ), but I'll look into adding a protection diode against wrong polarity.

pinkjimiphoton

i THINK ya need to jumper to that ground for the "off"led or there's no ground to the led circuit. i can't get my led to light, not that i really care enough to bother with it right now. i did not hook up that jumper i don't think. i will take a peek a little later and see if that's the case.

what i found is on this a lot of times i have to wire right to solder nodes, cuz the traces don't seem to conduct very well. some of it could be due to me reworking it so much, but i think thats what LED me to rework it so much.

i did use the power jack, and i put the 2200 cap right across the +/- of the jack itself. kinda tucked in under stuff.

best of luck with it!
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

gpcustomguitars

Well,

Resoldered everything as on your diagram, LED lights up OK, Clean signal is passing trough also, but no sound . What confuses me a bit is the part of diagram under the LED, saying OUT - is that just connected together or it actually goes to out and where?

I guess that both sleeves are grounded if one is, via the enclosure conductivity. Also, I think my pots are wired upside down, but then they would just work in reverse. Will try to fix it, and report on progress. Other that the obvious lack of instructions, kit is kinda nice, so I hope to get it to work.

pinkjimiphoton

5 bux says if ya didn't use sockets, one or both transistors are toast.
i've built literally, no exageration, hundreds of fuzz faces at this point.
this thing broke my nards all the way thru. i always build 'em npn ge with a negative ground. i had no pnp ge's to try, barry from guitarpcb.com was kind enough to hook me up a perfectly matched set of 2n404's from his personal stash <thanks, my7of9!!!>
and it fired right up.
if its passing signal from in to out in bypass, and the led is lighting, then the jacks and switch wiring are correct.
you mention that you may have the pots backwards. hey, it happens. it also happens that sometimes one will be backwards, but not both, so no matter how ya turn it down, it don't work. they can fight each other.

get to geofex.com and read rg's the technology of the fuzzface. the topology is basically the same any way ya look at it. same handful of parts.

on mine, like i said, i had to basically go point to point to wire it up, as the traces appeared to have failed all over the place. if you look at where it's marked board out, and trace it, <you will likely have to trace thru the circuit with a schem in hand, but it is an easy circuit to work with and will be good practice for you>
you'll see its a straight line from the middle post of the volume pot connection. on mine the trace is useless. its pretty ridiculous.

the kit is worth it for the parts, but the pcb is junk. i did get my led working, the original one fried.

make sure all your grounds connect. that appeared to be another issue with this thing.

if all else fails, and it turns out the transistors are toast, pm me and i'll try and hook ya up with some replacements to try.

good luck. you'll get it.

but use sockets. i know they suck and are a pain in the ass and fail... i mean shit falls and vibrates right out of them... but a dab of solder on a leg or two super quick once ya get it dialed in and you're good.
like i've said, i've built hundreds of these suckers... and this is the first time i smoked the q's soldering them in place which shows how sensitive they can be.
my advice also is leave a bit of lead on them and lay them down horizontally if possible, and always stick a roach clip or something on there as a heat sink.

hang in there.

post us some voltages... the batttery voltage,
the voltage where it enters the pcb
the voltages at e,b,c for both transistors

also try replacing the 8.2k resistor with a 10-20k trim pot... may make it easier to dial in a sweet spot once ya get it working.

good luck!
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

gpcustomguitars

No sockets :) I'm not bad with the soldering iron, so I figured I could tack these in place with no problems. I'll try to test them, when I figure out how, then replace with sockets if needed.
I'll definitely make sure that the pots are wired right side up, didn't realize it could be a problem - I thought the worst would be them working reversely, and check if all grounds are connected.

Thanks again for the help! Update coming soon!!!

pinkjimiphoton

i'm not bad with an iron either, BUT it took less than a split second of heat to roast q2 that was supplied. especially with the crummy solder out there these days.
i finally ran out of all my old school stuff and have been using modern solders and absolutely hate it. i have 3 or 4 different styles and guages now to handle different heats and for different uses, where i used to just use one simple style <forget the model number> of kester that i can't seem to find anywhere. smelled like a pine forest when ya used it. was awesome. so old the labels fell off the spool years ago ;)

you mos def got this. like i said, if the q's are toast... let me know.
a simple google search will help ya use a meter to test the transistors.

keep us posted!
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr