Fuzz face aion fx epsilon issues.

Started by rokinrandy, July 20, 2022, 10:10:45 PM

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rokinrandy

https://aionfx.com/app/files/docs/epsilon_documentation.pdf
Link for the build docs and pcb.

I guess this is The famous simple fuzz face circuit as done by aion fx known as the epsilon. A lot has changed since the xp days. And I'm still a bit new. My first real issue. so go easy on me.

Ok I give.   This is my fourth pedal and I'm overwhelmed.  I read the before you post thing.  The only thing I did different was c7.  Which is a 10pf multi layered capacitor.   I didn't have a npo/cog so I used an xlr or a regular one at 10pf.    I used an audio probe and I got signal through it so I assume that is not the issue. 



I couldn't find the transformer anywhere.   They are 5 bucks at mouser and won't be in stock for months.  So I went to eBay and got the same exact one from a guy in Indiana   He was charging like 13 bucks.   5 bucks shipping.  That's how bad I want this type of build.    I don't know how to isolate and test a transformer.  Maybe audio probe idk.   I'm assuming the need for it is the pick up selector switch.  Idk all I have is common sense.  I think. No experience.

I just don't know what I'm doing.   I have a pcb audition to rock it.  And a home made audio probe.  But I'm lost.   At first I was getting a faint signal..   But no fuzz.  Or much volume Which led me to believe maybe a transistor. Again no training.   Common sense.  I think. Maybe not.

Well now  I'm getting no signal at all when active.  And I don't think it's a transistor.   I moved and checked all the transistors and got signal on them all.  So I assume they are all good. 

   I guess I need to learn how to correlate with what I'm testing from the schematic.  But idk hopefully by posting this maybe someone can help me figure it out.   

I hear the fuzz is a simple circuit.   But with the transformer and switch it seems like it can get mixed up.   The switch gets a signal on certain legs . Then when you flip it changes.   But this is my first bout with a real issue.  Maybe I should ask where do I begin.    Out put ?   

I get a signal at the out put on the pcb where the wires go that connect with the 3pdt switch.  I assume that is the beginning.   And like the middle leg on one of the pots. Heck I've done forgot.  But I don't know what's supposed to be next.    Or even if I'm starting out right at this point.  Have to start some where . So if I'm not doing this post right forgive me.   If there is anything I need to do . To make a proper post I'll be more than happy to make this easier for anyone up to This challenge.   

Seems like it's too confusing for anyone to me.  But I have to try and see.   I'm at a dead end.










idy

#1
Breathe.
Welcome to the forum'
Breathe again.

Its nice to show photos of both sides of the pcb. People here love photos of PCBs. It looks like the pots are not soldered in. Double check that.

Good you have an audio probe and something (your phone?) to inject a signal.

Do you understand the schematic enough to trace the audio path?
It goes like this...( I am leaving out the feedback nodes)
C1
Q3 gate and source (just a buffer, should sound the same)
in and out the xformer (if it is switched in, other wise the signal goes in and out the toggle)
Make sure the "input" pot is set to max, clockwise. You should find your signal there on terminal 2 and 3
C4
Q1 base and collector, should be louder, maybe fuzzy
Q2 base and collector, should be loud and fuzzy
"bias" pot pins 1 and 2
C8
Volume pot pin 3 and 2

rokinrandy

Man thanks for replying. 
Yea it's all soldered in.  I used a small iron and the smaller solder more like you'd use on smd stuff on a lot of it.  But I make sure the solder flows and  takes and all that.  As a pipe man I've soldered a while so having it flow is a must. I'll take more picture though.

But I never ran through a schematic.   That's where I draw some blanks.  Also especially with the sptd switches and all that.   Maybe I'll take a video as well later on whatever it takes. 








rokinrandy

I forgot to breathe.  Yes I need to look at that scematix.  There are a few things I need to wrap my head around. I probably should have started on something easier.  Well I did.  I didn't have any problems.   I use those pin ic for quick removal and all. Auditioning transistors.   They all seem  good.  But I'm not getting a signal on both.  In q2 I don't think even though all the transistors seem good. . 

idy

What transistors are you using?
BC549C? Pinout CBE? Noticed the PCB is layed out for EBC?

We like to see the holes around pots completely full of solder. Probably not your problem, but soldering should be thorough, not skimpy.

rokinrandy

I'm guessing you want me to check where 3 and 4 is.  And see if there is a signal ?   If I do I'll get me wide to record the probe so you can see.

rokinrandy

Quote from: rokinrandy on July 21, 2022, 12:12:57 AM
I'm guessing you want me to check where 3 and 4 is.  And see if there is a signal ?   If I do I'll get me wide to record the probe so you can see.
I'm using exactly what's in the building docs.   Which is bc549c at q1 and q2. 

rokinrandy

Quote from: rokinrandy on July 21, 2022, 12:12:57 AM
I'm guessing you want me to check where 3 and 4 is.  And see if there is a signal ?   If I do I'll get me wide to record the probe so you can see.
.  That's no problem I have to do that later.  There are also an extra q1 and q2 with nothing in it.   I think he did that for a different build that can go o here.   I hope that Dosent cause any confusion.

antonis

Quote from: rokinrandy on July 21, 2022, 12:24:54 AM
There are also an extra q1 and q2 with nothing in it.   I think he did that for a different build that can go o here.

Just an option for using either TO-92 or TO-18 transistors.. :icon_wink:
(only one outline should be used - the other left empty..)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

duck_arse

as mentioned - the board silkscreen is wrong for BCxxx transistors. yours are in backwards in the photos. and we want some voltage measures, please.

and welcome, as ever.
" I will say no more "

idy

#10
Yes, what Duck said, reverse the transistors. Build doc says the legend on the PCB is reversed for these.

QuoteBC549C? Pinout CBE? Noticed the PCB is layed out for EBC?
QuoteBC549C is a great substitute with similar gain range as the BC108C. However, note that the TO-92 outline on the PCB uses the USA E-B-C convention, so the BC549C will need to be rotated 180 degrees.

once this is done you will need to physically push them in tight while testing: socketed transistors are a drag, begging for intermittent trouble. Once you get them working you will want to put a little bit of solder on them. Also possible to gently coat legs with solder (transistors, not your legs!) before pushing them in, making them tighter in the sockets.

antonis

"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

rokinrandy

Wow. Thank you guys. 
Sorry for my late reply I've been up to my eyeballs with work from my boss.  I'm so happy to hear how confident you guys are about the issue.  I will be more than happy to get the readings.  I have to learn how.  And try to see if we can flip this thing.  If it works you don't know how happy I'll be.  I just got home from a long day I'm going to bed.  But I'll get to it in the morning and start learning what I need to do.  Thanks so much.

rokinrandy

Quote from: duck_arse on July 21, 2022, 10:35:26 AM
as mentioned - the board silkscreen is wrong for BCxxx transistors. yours are in backwards in the photos. and we want some voltage measures, please.

and welcome, as ever.

Well sorry this is taking me so long.  It looks like I need to order a special tester to get all the voltage readings.  I will have to get one from eBay or something.   Amazon.  I hope you guys will still be around when I get back.  Thanks for replying and helping me

PRR

Quote from: rokinrandy on July 24, 2022, 09:51:52 PMIt looks like I need to order a special tester to get all the voltage readings.  .... I hope you guys will still be around when I get back.

Most of us have been here for years. They can't get rid of us. This section has posts back to 2003 (19 years!!) and the Archive section goes even further.

So go do what you do, family, work, shopping, etc, and most of us will be here. Enough for help. You don't need a reservation. We've had members go away for years and come back, cool.

But what is "special tester"? A simple volt/ohm meter, Digital Multimeter, is often plenty. Unlike car repair or knitting, you can't see electricity, your meter is your "eyes into the circuit". We like hi-rez photos of both sides, and voltage readings at major points (start with all 3 legs of any 3-leg part, to ground).
  • SUPPORTER

rokinrandy

#15
Well.  I'm back.  And I still have too much to do.  Oh I finally bought a tester.  I'll post pictures of the readings. Be right back.

rokinrandy

Quote from: duck_arse on July 21, 2022, 10:35:26 AM
as mentioned - the board silkscreen is wrong for BCxxx transistors. yours are in backwards in the photos. and we want some voltage measures, please.

and welcome, as ever.
I hope I'm doing this right as per requested.  So I'll just post pictures of the readings.  This is Q1;


And this is Q2;


And this is Q3


I also hope I got these in the tester the right way.   I'm assuming this is what you guys wanted to see.   I may need to go back and read carefully again.   It's been a awhile forgive me for any error.  Thanks

PRR

> I'm assuming this is what you guys wanted to see.

I wish you had asked before you bought that fancy meter. It *may* be useful, sometime, but first we wanted to know the IN CIRCUIT voltages.

"An electronic meter capable of reading 0-20Vdc and with an ohmmeter scale. ...Digital ones are available for as little as $10.00. I've seen them as low as $2.99... There is really very little anyone can tell you that would help if you can't measure and tell them what voltages you get. It will be much easier if your meter has some way to clip the negative/black lead to circuit ground instead of having both leads with only points. Most meters do. If yours doesn't, you could use a clip lead to do this, if you have a clip lead."
https://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Here's data from some totally different project:

------Emitter    Base    Collector
Q1    0.03v    0.56v    2.69v
Q2    2.10v    2.67v    3.93v
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rokinrandy

Oh ok I Mis understood.  But no problem. I wanted that kind of tester anyways. It will definitely make it easier for me to check all the parts before soldering them in for now on.  I'm not that good with chop sticks.

  I have some clips  And a multi meter with a dial.  It has an  ohms  setting .
I thought that was what duck arse was asking for. 

The transistors are making a connection on the sockets I haven't had any intermittent problems with the sockets. not yet anyways.  I figured that would be a good way to experiment.  I remember before making the post I flipped them all around 180.

When I get home I'll read closer into what your are trying to explain about getting readings in circuit.    and get those readings instead.   Thanks

duck_arse

a multi meter with a dial? can we see a photo of that, too?

you don't need the ohms range at the moment, you want the DC volts range, probably 20V. connect the black probe to the circuit ground, somewhere. power on the circuit, poke around w/ the red probe, record and report readings. probe each pin on transistors, supply +, signal in and signal out, can't hurt.
" I will say no more "