Axis Face - Need help getting Q2 biased -

[duck_arse]

re your last post, no, that's not right. re the post before that - I don't mean to sound rude, but wot the hell is that you've posted for pics? nothing showed this end, and when I looked at your posted link code, well, I dunno what that is. can you upload your imgs to imgur (for example), and then either embed the images in the page here (links ending with image extensions) or post a link to the complete page of images at imgur (e.g.)?

[Twhjelmgren28]

Hopefully those photos can be seen now.  Like I said, I put Q2 on the opposite side of the board b/c it was easier to see and mess around when I was having issues. 

I'm sorry you all had to witness those photos,    Duck Arse was adamant.  I definitely learned that neatness/organization in a pedal is an art. 

So I ended up pulling Q1 and testing it out of the circuit.  Same resistance issue.  Unfortunately, I didn't have a spare so I'm waiting for more to come (another thing learned - order several backups!). 

To be continued...

[duck_arse]

excellent - the photos have arrived. and when I say excellent, I mean ergh. not to be rude, again, but you need some soldering practice. your joints should be shiny bright, with just enough solder for the connection. maybe search a few of the soldering threads hereabouts, they have plenny links to "the good oil" on soldering videos and stuff.



some questions - if they have already been asked, well, we've turned the page, and I forgot. and sometimes, we ask these questions, and turn up some real gold nuggets.

what type number transistors are you using? have you searched-up the relavent [hmm, seem to have forgotten spelling again] datasheets to check the pinout (and polarity) is what you think? how did the flipped-under transistor connections change with the flip?

and - what type of soldering iron are you using, and what type solder, tin/lead or lead free? does your multimeter have a transistor tester, or a range marked hFE? do you have a spare perf you could start again on, if needed? AND - do you own a breadboard?

[Twhjelmgren28]

Yeah my soldering is bad. 

I am using the transistors listed on the schematic:  PN2369A for Q1 and BD139 for Q2.  Q1 had the B, C, E listed on the actual transistor.  Q2 I used a datasheet (and confused myself several times while connecting it - which added to my issues).  I looked at the datasheet while flipping the transistor so, pretty sure it was connected right (as far as pins are concerned, not as far as my solder joints are concerned). 

I'm using a cheap 40watt iron from Menards and 60/40 rosin-core solder (also from Menards). 

My multimeter does have a transistor tester/hFE - is this equivalent to "gain?" 

I do have several spare perf boards and plan on using one when I get the new transistors and I also own a breadboard.  I did have this circuit successfully breadboarded - I had Q2 voltage near 4.5 and it sounded great! Only started having issues when moving to perfboard.  It did eventually work and then stopped working again (perhaps I shorted the transistor when fitting it into the enclosure...)

[duck_arse]

the Q1 you can put into the multimeter on hFE setting, and it should give you a number. this will at least indicate the part is still 'okey dokey'. it takes a fair bit of work to kill yr average sillicon trannie, you have to really want it dead. the power transistor may or may not provide a proper reading, I'm not sure, but can't hurt to have a go.

I think - test parts, practise solder, redo board without offboard parts, then add offboards, then stick in box, then never speak of it again.

[Twhjelmgren28]

I think - test parts, practise solder, redo board without offboard parts, then add offboards, then stick in box, then never speak of it again.

Haha, done.  Thanks for the help duck_arse.  I'll give it one last hoo-rah.  Appreciate the help and I don't plan on ever speaking of it again.

[duck_arse]

keep us updated with your progress, though. and good luck.

[Twhjelmgren28]

Thanks again for all the help duck_arse and others who responded.  I got it up and running!  I ended up using all new parts to a new perf board.  I checked voltage at Q2 throughout the build just to see how it was affected. 

Here is what I think went wrong on my 1st try:  I initially had it up and running, resoldered several joints, then it wasn't working.  Prior me messing around with other parts and potentially burning out Q1, I believe my issue was bad solder joints to/at ground (among other things). 

For the new build, I used a bus wire for ground and that gave me better contact for each grounded part.  The second I grounded the fuzz pot to that bus, voltage changed as it was supposed to with the trimmer.

I've learned a ton from my first build here and have officially been bitten by the bug. 

Thanks for all the help guys!  I'll hopefully get pics up of the finished project if anyone is interested - the enclosure is currently drying from some clear coats.

Side question:  For the little tab that sticks up on the side of the pots, do you guys bend that over or do you drill a spot for it partially into the enclosure from the bottom?  I assume it's there so the pot doesn't move / stays positioned correctly in the enclosure.  I ended up drilling partially into the enclosure but the pots still don't sit flat - also, I drilled too far on one of them and have a bit of a pimple on the top of the enclosure (I'll just cover it with the washer).   

[duck_arse]

don't get me started on pot pips! your choice, either snap them off, use them as is, or file them down some for clearance. I like to use sub-panels, any old carp aluminium I can find, drill a mess of holes in and mount the pots to, then mount the panel on something else in the case, with only the shaft holes for the pots thru the front/top panel of the case.

you can also pack the pot ferrule [boss? flange? threading?] with enough washers to clear all your foulings.

but like I say, don't get me started. good work on the fix. how is the soldering coming along, nice and shiny? and we want to see those finished photos, too.

[Twhjelmgren28]

Here is the finished product.  Disclaimer:  This is an axis face circuit by Fuzz Central - I put it into a box with a different name just for my own personal flavor.  Not sure what the etiquette is there...If you look closely, you can see my hairy hobbit foot in the middle pic.

[Cozybuilder]

Congratulations, glad to see you finished this project. The enclosure looks great!

[Kipper4]

Nice.
I'd try to keep the offboard wiring shorter especially in a fuzz.
I'm not much of a fuzz sort 'o' bloke. However I like the Axis Face. Great for modding too.

[duck_arse]

cozy beat me to it. and kipper, on his way to a party. I was busy scrolling your pics ......

what's next on the build list? and if you solder it together and shove it into a box, you can call it whatever the hell you think apropos*.

[* registered trademark, copyright, patent pending.]

[Kipper4]

True that Cozy.
It's smart.

[Twhjelmgren28]

Thanks guys!  The picture makes the box look a bit cleaner than it is - I need to be more patient on my paint coats and I definitely need to get the inside of the enclosure cleaner/neater.

what's next on the build list? and if you solder it together and shove it into a box, you can call it whatever the hell you think apropos*.

[* registered trademark, copyright, patent pending.]

I guess my to-build list is growing by need.  I'm thinking of doing a boost pedal (I'm not a huge fan of using my guitar volume but would like something to get me out of the mix a bit for solos) - I would mainly use it as a clean volume boost but wouldn't mind throwing it before some drive pedals also.  I was looking at something like a ZVex SHO, Sparkle Boost, or LPB-1.  Any suggestions?