Roger Mayer - Axis Fuzz  [traced]

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Post by Fanum »

Well, the funny thing is that he initially thought the fuzz with these components .... Perhaps the original Axis Fuzz them had ... Octavia have ... and the axis fuzz is its close relative ...
Of course, now no longer used (do not see the components and even the slopes, as can be seen from the new AF).
Ah !.... confirm .... the sound changes enough .... with or without. (ie audible)

Excuse my poor English
Fanum

P.S for you which is the right hfe of the transistors?

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swt
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Post by swt »

i have a bunch of the motorolas, so let me check for hfe of the ones that bias ok....

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Khaba-khaba
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Post by Khaba-khaba »

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mini_mod_for_axisfuzzschem.gif
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Post by Fanum »

swt wrote:i have a bunch of the motorolas, so let me check for hfe of the ones that bias ok....
UP :P

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swt
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Post by swt »

ups sorry for the delay...i'm on holidays. Give me a couple of days and will check them...

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Post by Fanum »

swt wrote:ups sorry for the delay...i'm on holidays. Give me a couple of days and will check them...
Don't worry.. :popcorn:

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andres_a884
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Post by andres_a884 »

Hi,
Does anyone Know if this layout can be build with AC127 and Ac128 I have a couple of them and want to use it.

download/file.php?id=6119&mode=view

Thanks,
Ariel.

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andres_a884
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Post by andres_a884 »

Built the PTP board and works perfectly, now I´m testing AC128, AC127 and B324 germanium transistors searching for the goods ones, with silicon transistors works fine.

Some photos,

http://www.flickr.com/photos/38980696@N ... 140962499/

Which is the best way to test germanium transistors ?.

Thanks.

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DougH
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Post by DougH »

Fanum wrote:Well, the funny thing is that he initially thought the fuzz with these components .... Perhaps the original Axis Fuzz them had ... Octavia have ... and the axis fuzz is its close relative ...
The story from 'somewhere' (RM?) was that this filter was needed in Europe but not in the U.S. (?!?!?!?) Smells like BS to me... I suspect it was part of whatever circuit he used to develop the Axis Fuzz from, and the Octavia, and whatever else he also based on it. Then at some later date he realized it wasn't needed. Just a guess... YMMV.
"You have just tubescreamered or fuzzfaced yourself " -polarbearfx

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Post by analogguru »

analogguru wrote:The use of this RC-Network is described here on page 3:
http://www.tcaas.btinternet.co.uk/jlh1970.pdf

These components reduce the (inaudible) High-Frequency-response and are used to avoid High-Frequency-oscillation. Therefore not really needed in this application and omitted.

analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.

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DougH
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Post by DougH »

Thanks AG for clearing that up. I thought this circuit came from somewhere else (i.e. not RM).
"You have just tubescreamered or fuzzfaced yourself " -polarbearfx

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Post by GBlekas »

IvIark wrote:I may as well add this to the thread for anyone interested in turrets or ptp wiring:
The attachment Roger Mayer Axis Fuzz - IvIark.png is no longer available
On Fuzz Central there is a recommendation to omit the 220R + 1nF in column 5 so it may be worth experimenting.
Axis fuzz turret layout.PNG
I was looking at the layout and just wanted to point out a duplication of a cap.
I believe only one of these are needed, if I am following the schematic correctly.

Looks cool though so thanks for your time!

George

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Post by IvIark »

Yes you're right, it's been duplicated so you could make it 1 column narrower. It looks as though I've shown the volume pot backwards as well, you should swap 1 and 3. That'll teach me to interpret pots on schematic literally, although in my defence that was one of my early layouts! :D
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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Post by andregarcia57 »

Hello ... Does anyone know Hfe values of Q1 and Q2 from the original RM?

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Post by Cigano23 »

andregarcia57 wrote:Hello ... Does anyone know Hfe values of Q1 and Q2 from the original RM?
They're around 150-200hfe.

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Post by andregarcia57 »

another fuzz for the collection, I love fuzz sounds
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Roger Mayer AXI FUZZ pcb.jpg
Roger Mayer AXI FUZZ.jpg

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Post by quantum »

In the 80's guitar player put out a buyers guide for fuzz....in it they had quotes from the manufacturer on many pedals. Regarding the axis fuzz Roger Mayer said the axis fuzz used germanium transistors in a push pull arrangement. He also implied that the circuit was not following conventional design and actually used the phrase like "not correct".....
My guess ..just like the fuzzface and all the problems to do with temperature and biasing , he switched from germanium to silicone. He must of done this quickly as their are no schematics or info on germanium axis fuzztones, other than what appeared in the guitar player buyers guide.

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Jimi McRuff
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Post by Jimi McRuff »

I've read a number of articles and different threads regarding the Roger Mayer Axis Fuzz and have never came across any talk about component values in respect to gain.

I'm aware of the use of a variable resistor instead of the 47k leading to the collector on Q2. Likewise, the omission of the 220 ohm resistor/.001uf capacitor at the base of Q2. But what about some of the other components?

Take for instance the 39k resistor/22uf electrolytic capacitor at the emitter of Q2. Would changing either of these values (up or down) increase gain of the transistor? Or is it pretty much maxed out at these values?

Another area I'm interested in is where the 220 ohm resistor (coming from the emitter of Q1) joins with the 47k resistor. At the junction it runs off into a 22uf electrolytic capacitor and .1uf capacitor before meeting up with the 2k 'drive' potentiometer. Again, would changing either of the values affect gain or tone of the fuzz?

I would be interested to hear from anyone who may have played with the values and what the results were. I've built a couple of these pedal and always stuck to the schematic. I just curious to see if there may be 'tweaks' like when building a Fuzz Face.

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