RM Axis Fuzz Build Report

[RDV]

I'm off work this week, so I'll be doing some recreational building. The Axis has been on the list for some time, but I had to order some stuff. I finally got around to building it today on perf and I dig it. It sounds better to me than a FF by a long shot. It's great for psychodelic lead playing for sure. I've been doing the opamp stuff for so long I realized this is the first fuzz I've built in about 8 months!

I used the schem at Fuzz Central and winged it on perf and fired up right off the bat with no de-bugging!

HAH!

RDV

[petemoore]

Yupp that's a unique sounding hHot One.
 Sounds very much a later Hendrix type thing.
 Starts Grinding Pretty Good when I turn it up. Definitely suited for that 'letting loose the volume thing' and Jamming.
 Very cool circuit !!!
 Just different than a 'regular' Face.
 Haven't tried it with an Si amp... :?

[brian wenz]

hello Hello Randy--
       Welcome to the Axis Club!
Try decreasing the 47K down to around 22K to remove some of the "woofiness" from higher gain settings.
Brian.

[brian wenz]

hello Hello Randy--
       Welcome to the Axis Club!
Oops, sorry...double post.
Brian.

[phillip]

I'm thinking about making the Axis Fuzz the next project at Fuzz Central, especially since I have a nifty new layout for it that's smaller and more compact than any other that I've seen around the internet.

Brian, is the 47K that you're talking about the one that goes from the collector of Q2 to the junction of the 220R and 22uF capacitor on the emitter of Q1?

Phillip

[RDV]

hello Hello Randy--

Randy is what I am, Ricky is who I am. :wink:  :wink:  :wink:  :wink:  :wink:  :wink:  :wink:

RDV

[b_rogers]

the axis is a good one.  welcome to the club!

brian is right about the 47k, either put a 22k there or a 50k pot.

i havent messed with the 22u yet but i want to make a "MultiAxis" with trimpots and sockets.


Brent

[Doug_H]

a;lkjd

[MartyB]

Great-sounding fuzz.  Mine sounds better than my easyface, tonebender and my boutique fuzz builds.  For all-silicone trans, it's very impressive.

[RDV]

The 22k feedback resistor mod's a keeper. Boy, this thing makes me want to sweep pick and string skip and do all that trick stuff. It's neat.

BTW I did my little perfy thing on a 1 1/2" sq piece. I guess I'll drill & paint a 1590B tomorrow. Thanks to all for input.

RDV

[petemoore]

There was some type here a while back about the 820k/180k resistors not making much/any difference when replaced by a 1meg.

[RDV]

I wonder which 2N3904 & 6 brand he uses. I got mine off of eBay and I have no idea what brand they are. They've got a gray front face with "W46" along with the #s. Maybe ON Semi?

RDV

[b_rogers]

i subbed the 1M for the 820k180k no problem...

phillip,i would love to see your layout for the axis. im sure a lotta folk would.


i did mine up "schemo style"  with no issues, but smaller would be better!

was one resistor ever determined to be the bias resistor(s)? 680K? 22K?


Brent

[brian wenz]

Hello Hello Rudy----ooops, sorry about your name!  
      Errmm.... I think the 2n's that were in the original were English brand but I don't know which ones.  My  first build was with Radio Shack 2N's and it sounded o.k., but I used Fairchilds for my next one and they're better.  For the third one I put a BS170 in place of the 2N3094 and that sounds REAL good.  [Somebody else try it and let me know.]   I put a 50K pot in place of that 47 res.  and tweaked away for about six months but I finally settled on using a 22K res.  [Too many choices can screw up a perfectly good band practice!]
  Phillip--- Yeah, I'm pretty sure that's the 47K I'm talking about [I haven't got a schematic around here.]
Brian.

[brian wenz]

Hello Phillip--
    Yeah, that's the one!   I just checked the schematic at yer site..
[hey, do you think Rudy is pissed???]
Brian.

[RDV]

Pissed as a NEWT!!

RDV

[brian wenz]

Hello Helloo-
    Uh oh.....drinking again!
Hey, one of the reasons that Hendrix liked the Axis so much was 'cuz it worked better with humbuckers then the FF.  What do you think of the way it matches up with humbuckers??    I like it alot better then the FF.
Brian.

[STOMPmole]

My RM spaceship Axis has the silver faced transistors (I'm not sure who manufactured them).  I picked up a few that are an exact match (cosmetically) at a local surplus store.

For those that have built this pedal...did you do anything to tweak the bias on the transistors and/or select a specific gain transistor(s), or did you just throw 2 transistors in the circuit with the schematic valued resistors and call it good?

It's odd that Hendrix would like it better because it matched up with humbuckers being as he rarely used humbucking guitars.  It DOES work better than the classic fuzz/Fuzz Face with humbuckers though.

I prefer the Germanium FFs for bluesy Cream/Hendrix distortion, but the Axis is definitely an awesome sounding Si Fuzz.

[brian wenz]

Hello Hello-
      Hendrix was using Gibson SG and Flying V guitars more and more from 69 - 70.  This probably had alot to do with the shabby treatment he got from Fender on his US tours.
Brian.

[brian wenz]

Hello Hello Again--
   Oops, forgot........I did not alter any values from the schematic for my copies [outside of changing that 47K to a 22K].  I didn't do any tranny matching, either.  As mentioned before I built a version using a BS170 that sounds great, too.  
Yeah, I remember those "silver-faced" trannys......I might even have one or two in a box somewhere.
Brian.