PNP tonebender problem

classic Classic list List threaded Threaded
14 messages Options
Reply | Threaded
Open this post in threaded view
|

PNP tonebender problem

Marbles
Hello again ;)

So.. after a few succesful builds, I thought I would start something smaller and understand more. Well... I maybe unwisely started with a PNP tonebender (compact layout), cause I bought a batch of GT308b's a while back.

It's my first PnP circuit. I wired the switch as usual ('Skreddy' layout). I have sound in bypass, but none when I turn it on.
So.. I messed up somewhere. First I wired the battery snap with the red wire to -9... I realized that was pretty foolish, switched it but still nothing. I thought maybe I couldve damaged the caps with polarity, so i replaced those. Still nothing.

Knifed the hell out of it, still nothing.

I took out my probe, I have signal at the input of my board at the one side of the 1m resistor, but that's it.

The start of  the 47u cap gives nothing. I'm not sure where to probe, cause i haven't used it that much.

Does anyone have an idea what could be wrong?


(also, the ground connection on the circuit is wired to the ring right?)


Hope anyone can help!
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

rocket88
Administrator
First things first. Can you take any pictures of the board and wiring? A lot of times,  IME, it ends up being something I missed and getting pla fresh pair of eyes on it figures it out fairly quickly. Also, can you give the voltages of the transistors? They could have been damaged when power was supplied improperly.
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Travis
Administrator
In reply to this post by Marbles
GT308 have a BCE pinout. Did you twist the base and collector around?
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Marbles
Thank you guys for the replies!

I was in the middle of taking pictures (you're right, a fresh pair of eyes is often needed, some parts you just skip automatically) when Travis' reply came in...

DOH! I was so focussed on having the emitter in the right place, that I did not pay any attention to the base and collector. Thanks Travis. Sometimes it's the simplest thing!

It fired up with the transistors I used before, so no damage done thank goodness. Sounds pretty awesome too! My first germanium fuzz.
Thanks a lot, if you'll excuse me, i'll be swapping trannies (though the Q1 79 and Q2 114 sound pretty great) and blasting out Stooges riffs now.
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

rocket88
Administrator
haha. nice man. see, told you it's always stupid things we miss. glad you got it up and working . how do you like it now?
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Marbles
Yeah you're right haha. Been staring at it for hours and just couldn't figure it out. Such a low parts count..
It's great so far! Haven't properly biased it yet, but like the characteristics.
Only used to muffs and silicon fuzz faces. It's great!
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

rocket88
Administrator
awesome. glad it's up and running and sounding good. after you get it biased, i'm sure you'll be even more happy with it. btw, be aware you will be bit by the Ge bug, and end up addicted like the rest of us.

if you think that's bad, how about spending 2hrs troubleshooting a build only to suddenly realize that you didn't put in the IC's or transistors . needless to say, i was beyond pissed, especially with myself. it happens to us all.
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Marbles
Haha, I'm sure I will

I must admit.. I've been there haha. Trying to get a MXR micro amp to work and finding out the socket missed the IC...

Thanks for your input. You helped me before, it's very much appreciated. I have to learn a lot, and am. Reading books, getting to know some electronics. To have a place where people with knowledge can help a guy out is awesome! So, thanks again to this forum for another working pedal ;)
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Travis
Administrator
In reply to this post by Marbles
Congrats on getting the pedal working. That can be a hard problem to see because your board will look fine, but it's a good thing to check when troubleshooting.

Which tone bender version did you make? I like all of them, and blasting stooges riffs
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Marbles
It really is right??
Especially cause when i was measuring them on a MM, the pinout was 'correct'. Oh well, problem solved thanks to you :)

The version I build was this one: http://tagboardeffects.blogspot.nl/2013/03/vox-tonebender-compact-version.html

I guess that would be MK I?

It's my first time exploring the world of tonebenders. I like it so far. It sounds really aggressive in a non-metal way, treble-ish but not as fizzy as my sillicon fuzzface. Hope it cuts through the mix.

Everyone should always be blasting Stooges riffs haha.

Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Travis
Administrator
Ahh. The two transistor Vox is most similar to a Fuzz Face or MK1.5 Bender. Not close to the MKI at all (which is an extremely difficult build to get sounding right).

Btw there's a lot of talk that Ron Asheton used a Fuzzrite. David Main has pointed out that most pics online show Ron using a Vox Bender and the Fuzzrite won't really get you close to his sound. So seems like you made a great choice for your Stooges fuzz :)
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

rocket88
Administrator
surprisingly it's true. long story short, i know someone that knew Ron Asheton back in the day and it was a vox tonebender, not a fuzzrite. so you will totally get that classic stooges fun house chaos with this build.
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Marbles
Straight from the horse's mouth eh? That's great! You 2 must be right. I have seen some pictures with what looked like a JEN tonebender, but wasn't sure.

I did build a fuzzrite one day, but it sounded 'thin' instead of trebly (have no idea how to describe sound sometimes haha, must be the dutch language barriere) I really liked it for 60's psychedelic fuzz, but not for something 'mean'.

I have to say I get the Stooges characteristics out of this one for sure. Still not really there though.
The attack doesnt sound that great when it's turned down, a bit honky even. It feels it has more gain than for example Fun House. I must say that of course I only played it on a small practice amp, so volume might change a lot too probably.

I just haven't got around to tweaking, cause from 9 o clock, it just sounds so really good haha. To unplug it  and swap trannies feels like a shame for now, enjoying it too much.  
Reply | Threaded
Open this post in threaded view
|

Re: PNP tonebender problem

Travis
Administrator
I recently got an original Fuzzrite and the 2n caps each have another 2n cap wired in parallel adding up to 4n each. So where you see a 2n or 2n2 in the Fuzzrite, try a 3n9 or 4n7 or two 2n/2n2 in parallel. Still not gonna sound like Stooges but sounds great IMO

Fuzz Face types (like your VOX build) typically sound best with the fuzz control up at max or pretty high. If you want to cut the gain use your guitar volume control instead of the fuzz control