Greasebox
Another cracking fuzz from DAM (the GB-83). This one is a fettled silicon MkIII/IV Tonebender of sorts. The vero that's out there has taken a stab at the two precision resistors that are in heatshrink on the original pedal and it isn't right. The biasing is off.
The resistor from Q1 base to ground needs to be something in the range of 39-47k. We stuck a pot on and turned sustain to max which squealed like hell, then adjusted the pot until the squeal went. Ours ended up at 42.4k. Insanely we had a 39k carbon comp that measured exactly that, gotta love those tolerances! Anyhow it sounds great, very much like the clip on the DAM site.
No decal?! Yup, another hammertone finish done by ColesBD of the Madbean forum. Classy.
(http://juansolo.demon.co.uk/stompage/images/greasebox-o.jpg)
(http://juansolo.demon.co.uk/stompage/images/greasebox-i.jpg)
Skeletor
More from Matt's transistor stash. This is another MKIII Tonebender, this one for Matt.
(http://juansolo.demon.co.uk/stompage/images/skeletor-o.jpg)
(http://juansolo.demon.co.uk/stompage/images/skeletor-i.jpg)
Frank Face
Matt wanted a Fuzz Face that cleaned up. So we went through a load of his scavenged transistors and these got the best pair in it. This might also be the quietest Fuzz Face I've ever encountered when it comes to noise.
It's a Frank Face as the stash was Frank's (Matt's grandad).
(http://juansolo.demon.co.uk/stompage/images/frank-o.jpg)
(http://juansolo.demon.co.uk/stompage/images/frank-i.jpg)
Fantastic!
as usual ;)
Josh
I wanna be your friend.* :P
*like, this specific friend.
That Frank Face has got to be one of the coolest pedals I've seen in quite some time! And that includes the story about Frank himself! Makes me a bit sad that I'm from an agricultural background (no need for cool electronic parts there...) from one side of my family, and carpenters on the other side....
Paul
I love them all, but that Skelator graphic is the best single-image graphic I've seen in an age. I wish I could finish boxes like that!
Very nice looking (& I imagine sounding) stomps. I really like the skeletor
The Skeletor graphic was one Matt specifically wanted. It just turned out to fit with the layout perfectly. Likewise he wanted a FF vibe with the other. Makes a change from the zombies and monkeys (and indeed the zombie monkeys) he usually requests :)
Gorgeous builds dude.
Your friend is one lucky guy!
Gonna have to try out the GB83 circuit too! Never enough fuzz!
lots of the good stuff in there!
My 2nd action figure was Skeletor! He-Man was the first ;D
Nice builds man :)
Nice! I love the smiley face on the Frank face. Very nice touch...
Nice pedals! I need to hear a greasebox, was tempted to make one of these on vero, I know of a couple of layouts but am weary of them being wrong... too bad
I suppose when I tackle this, I will socket some resistors and replace them with pots to find the sweet spot.
Hey out of curiosity... What kind of cap is that 220p? I have never seen one like that before?
I may tackle the grease box and use a couple pots to bias it to my liking...
thanks!
Jalmon -- it's a polystyrene cap, from memory. SB stock them.
Quote from: alanp on May 27, 2013, 05:15:45 AM
Jalmon -- it's a polystyrene cap, from memory. SB stock them.
Yup, it's a poly cap.
Quote from: jalmonsalmon on May 19, 2013, 05:14:59 AM
Nice pedals! I need to hear a greasebox, was tempted to make one of these on vero, I know of a couple of layouts but am weary of them being wrong... too bad
I suppose when I tackle this, I will socket some resistors and replace them with pots to find the sweet spot.
The vero I used was this one:
(http://juansolo.demon.co.uk/stompage/schematics/DAM/gb-83.png)
I just compacted it a lot. The one to socket is the 470K next to the 4n7. Stick a pot on it and adjust. I suspect something in the region of 39-47k should work.
ah okay! thanks guys. Is this about the same as SB carries? http://www.mouser.com/ProductDetail/Xicon/23PS122/?qs=sGAEpiMZZMsh%252b1woXyUXj2Wk4Z3nZoF9SxDl0XPr0tM%3d (http://www.mouser.com/ProductDetail/Xicon/23PS122/?qs=sGAEpiMZZMsh%252b1woXyUXj2Wk4Z3nZoF9SxDl0XPr0tM%3d)
I live about 45 minutes away from where I see packages shipped from mouser so they deliver the goods about 3 days after I order stuff... So for most parts I like to use mouser.
Heyas Juan,
I finally made a GB-83with the above layout and I ended up basically using a 500k pot for the resistor that is on base of Q1 to ground. Originally I had the 43k resistor there and it would not bias at all but as soon as I out the 500k pot on there and cranked it up... pedal works perfectly, sounds like the clips on youtube.
I think when I measured that pot it was around the 350k range so I am wondering what is wrong?
Maybe the transistors? lol
I have a the same BC547B / BC337 Q1/Q2 combo
anyway! CHEERS!
Great pedal imo.. works great with a deluxe reverb amp... has a lot of mids
They'll be nothing wrong. If you read the thread on FSB people are finding wildly different resistors work for different builds. I'd just do what you did. Stick a pot in, twiddle it until it sounds good and then swap a resistor in of that value. Alternatively just drop a 500k trimmer in there.
Cool, I just tuned it by ear to where it sounds good to me.
Yeah I find this GB-83 to be a great circuit for hard rock / blues stuff and it loves guitars with humbuckers and Fender amps! Has a nice midrange crunch to it and is different then any of my fuzz pedals.
Next up is a FZ-673 ;D
I'd really like to know if DAM selects the transistors in the GB-83 for a certain hfe?