RM AXIS FUZZ

[petemoore]

I'm believing that one doesn't really need a 100w amp to have Huge amp tone.
 Make no mistake, a teeny amp won't 'shake' your strings and wood for you like a 100w [just going to say Plexi...to me the industry 'standard' by which amps are judged//[Hey J.M.]...causeing the hamonic feedback loop they're so famous for...but as far as tube/speaker loading, freqiemcy resposne,.. and overdrive characteristics...anything from 2000+watts to <.2 watts can get that...[.2watts is probably an overstatement, kinda hard to find the 'right' speaker for amp loading at that level].
 the Moral' is: a overdriven or not overdriven 'tube influencied tone' can be attained with a very small tube amp and speaker.

[brian wenz]

Hello Hello Hungeryhippie--
    GOOD ONE!!    Looks like it was just a matter of biasing to the brand of tranny......
Brian.            [p.s.--what amp are you playing through??]

[brett]

Thanks to everyone who contributed to this thread.  I'm building an RM Axis fuzz tomorrow (skipping off work AGAIN), and this thread has alerted me to many things, including the need to watch the biasing in this circuit.

On the topic of over-driven amps and wattage, I use an old MusicMan 65(kinda like a Twin Reverb).  It has a "Lo" and "Hi" power switch.  On "Lo" it runs at half voltage (= 1/4 wattage).  To be able to max out at 16 watts is great.  99% of the time I use the low power setting.  Turned up loud it still leaves a slight ringing in my ears afterwards.   :twisted:  I don't know how you guys with 100W of tube power and 4x12s manage to get heavily overdriven in a household setting without bleeding from the ears. :shock:

[Doug H]

Thanks to everyone who contributed to this thread.  I'm building an RM Axis fuzz tomorrow (skipping off work AGAIN), and this thread has alerted me to many things, including the need to watch the biasing in this circuit.

On the topic of over-driven amps and wattage, I use an old MusicMan 65(kinda like a Twin Reverb).  It has a "Lo" and "Hi" power switch.  On "Lo" it runs at half voltage (= 1/4 wattage).  To be able to max out at 16 watts is great.  99% of the time I use the low power setting.  Turned up loud it still leaves a slight ringing in my ears afterwards.   :twisted:  I don't know how you guys with 100W of tube power and 4x12s manage to get heavily overdriven in a household setting without bleeding from the ears. :shock:

I suspect they use attenuators and/or earplugs. I hope so anyway...

(I don't think it's a household situation either. )  But IMO you don't necessarily need a lot of wattage. I think it takes a tube amp that is breaking up on its own a little, IMO.

Doug

[brian wenz]

Hello Hello--
  Houshold....   What's that?!
Brian.

[aron]

i did try different transistors in Q1, all 2n3906's, but all the same results,

the one thing i forgot to mention is, its also hard to concentrate with my other half going "blar blar blar Fuzz pedals is all you ever do blar blar blar" its even called Fuzz Pedaling, in my house (flat) now no matter what type of effect it is, I showed her the Dr Q and demonstrated it, "is that a new fuzz pedal!" hmmm. Well she is Norwegian.

Peace to you all cos i know i aint the only one who gets an earfull.

That is funnY! I hope it's funny to you.  

[petemoore]

I use the smallest Tube job I have, The RCA Victor.
 Sounds exactly like my Marshall [NOT}
 But I have been tuning with these two for long enough I know when it's sounding good on either amp, and can compensate for the EQ and Gain differences from experience now...moslty the Big amp has more gain and highs, but tuning them is a snap once I'm in the ballpark.
 I feel certain the earful I have gotten would have been greater in volume if I was doing mostall my tuning on the 50 watter.

[Hungeryhippie]

this is my amp and axe for Brian cos he asked


http://www.geocities.com/hungeryhippie/Hungerhippiekit.html


aron, Yes it is funny, so funny i had to share it   but i have brought her a big bunch of flowers now and she couldnt be happyier


brett

good luck with your axis, i wish i was home


Peace

[brian wenz]

Hello Hello HH--
    Thanks!  
Yeah , I remember that you posted a pic of your amp before......sorry for my bad memory!
Brian.

[Doug H]

I went ahead and built the axis the other night. I had a pre-drilled box that was left over from something else and it took me about 3-1/2 hours. (Still have to paint it and install an LED but it is basically finished.) I used a fairchild 2n3906 for Q1, motorola metal-can 2n2222 for Q2, and the 27k feedback resistor mod that Brian suggested and it sounds great. I did it on perfboard, and if there is any interest I'll post the layout, it's pretty simple.

This will give me a fun toy to play with when I need a break during my amp build.

Doug

[brian wenz]

Hello Hello-
  Yeah, that 27K helps reduce the "flab" in the low end.  
I wonder how it sounds through a Fender amp with a master volume???
Brian.

[petemoore]

The 27k mentioned in the last post...that would be the far left resistor on the schematic?

[petemoore]

Sorry the far RIGHT of the schematic...is that the R your referring to as being a good value of 27k?

[Doug H]

Sorry the far RIGHT of the schematic...is that the R your referring to as being a good value of 27k?

It's a sub for the 47k feedback resistor that ties into the 22uf above the gain control.

Doug

[Doug H]

Hello Hello-
  Yeah, that 27K helps reduce the "flab" in the low end.  

Brian.

It also helps the gain control work a little better and it is easier to find some of the "in between" tones. With the 47k, it goes to the "over the top" swell sounds much more quickly.

Doug

[brian wenz]

Hello Doug--
  Have you tried using a BS 170 for Q2??
Brian.

[Doug H]

Hello Doug--
  Have you tried using a BS 170 for Q2??
Brian.

No, didn't consider using a mosfet. How does it sound?

Doug

[phillip]

I tried using a 2N7000 MOSFET in place of Q2, but it had some biasing problems in there...had that "farty" gated sound.

Phillip

[brian wenz]

Hello Doug--
 Mine sounds.......................real good!!
I haven't done a  shoot-out between the stock version and the mosfet version yet but  I think the mosfet may be a little clearer then the tranny.
Didn't have any bias problems but I'm wondering if it couldn't be "fine tuned" for the BS170 a little better  []
Brian.