Tuesday 6 March 2012

Foxx Tone Machine

So I may as well include this one too.  Manufacturers info:

Manufactured for only a few short years in the early '70s, the fOXX Tone Machine was stomped mightily by artists ranging from ZZ Top to Adrian Belew, Parliament-Funkadelic to Peter Frampton. Its legacy has lived on as a new generation of artists (Nine Inch Nails, Beck) has discovered the fat-backed, fuzzed-out sound that screams (in a very fuzzy way, naturally) fOXX Tone Machine!





71 comments:

  1. Damn! Sat down to do this and haven't got any 220R's... could I run two 100r's parallel to make 200R? and even run a 10r too to make it up to 220R?

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    1. In series mate, if you put them in parallel you'll end up with round about an 8 ohm resistor. Having said that, all that resistor does is set a minimum level of fuzz which stops the effect going silent in the fully counter clockwise position like the Maximus does. Just use a 100 ohm instead which will let the pedal go lower gain than stock, but keep exactly the same "full fuzz" sound.

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    2. Haha Doh!.. Ok mate, cheers. That sounds like it might be better.

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    3. http://www.1728.org/resistrs.htm

      Used this for WLUD666's switchable power input resistors..
      +m

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    4. Cheers mirosol..That'll come in handy I'm sure.

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  2. Well It fired up first time and what a beast it is!! To me it sounds like the perfect mix between a Meathead and a Hyperion. And octave up is perfect, not too piercing like a lot of others..

    I put her in a little black hammerite number ;o)

    http://img546.imageshack.us/img546/6141/foxx.jpg

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  4. Last time I made this i used a toggle, How would I wire up a DPDT stomp with LED?

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    1. I think it should go just like this:
      http://mirosol.kapsi.fi/varasto/boxes_other/FTM_DPDT.png

      Assuming that the upper octave is on when switch is shorting SW1A and SW1B :)
      +m

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    2. Cheers Miro, much appreciated ;o)

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    3. That is very helpful. Anode to +9V... Correct?

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  5. Can't get the slightest sound out off this, so freakin weird. Had similar problems with the Fender Blender build. All the transistors voltages match those provided by GGG but still almost no sound. I probed the circuit and there is sound up until diode 2. Any tips?

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  6. Just finished building this, it'll pass a signal but it's really quiet. I checked all the transistor voltages and they're in line with the GGG values. Any suggestions where to look? I've built a few of these that have worked fine, never had this issue before.

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    1. The times i've had similar issues, there have been a slight short around the output, leaking the signal to ground... Since the voltages are ok.. Have you guys tried probing the circuit to see where the signal dies?
      +m

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    2. Actually have two of these going right now, one works and the other doesn't. After a bit of poking, D2 measures 4.3 on the anode, and 4.25 on the cathode on the one that works, while the one that doesn't measures 8.4 and .04

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    3. So it could be a burned diode that passes most of the signal straight to ground. Have tried swapping those diodes?
      +m

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  7. Just finished building this and what a FUCKING SEXY BEAST!!!11 hell yeah probably scared a couple of neighbours. thks Mark for the lovely layout!

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  8. JUst build this effect. Love it, very loud an sharp, so it has been boxed in a matter of hours. Only thing is that the B50K for volume is overkill, on next builds I'll use a log, as the volume is useless from 9 o'clock.

    Great octave, but the Tycobrahe remains the best for me :)

    BR

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    1. For me the FTM has the most pronounced octave and useable non-octave fuzz versus the Tycobrahe, Scrambler, and Fender blender. Different strokes...

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  9. Hallo, some of you have experimented an effect like if the sound was coming and going, kind of wave, while you sustain the notes? I didn't build it from this layout, used one I found, but I don`t know if this may be caused to transistors gain or it could be something else..
    Thank you,
    Sergio

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  10. Any chance someone could show a version with a "swell" knob on this like the Prescription Electronics Experience?

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    1. ...It's my only Christmas wish.

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    2. what i could find: http://s114.photobucket.com/user/rousejeremy/media/swellvero.png.html
      Don't know if it's the same as the PEE

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    3. http://user.eduhi.at/aquataur/aquataur/musicstuff/swell.PDF
      and http://web.archive.org/web/20000928141340/http://www.geocities.com/CollegePark/Library/1355/experience.gif

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    4. I'd cast a vote for the Experience Pedal too.

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  11. Volume 2 to Output, Fine. But I can't see volume 2 or output on the verobard.. ? Nothing comes out of it?

    What about my 3PDT wiring?

    Thanks,
    JP

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    1. So you basically didn't get it.

      "Volume 2" is the middle pin of your volume pot. The wire you solder to that lug is your output.
      +m

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  12. is that ok to substitute de 3nf for a 4.7nf? would i get more bass?

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  13. Heya,

    This is my first pedal. All the voltages are lining up with GGG except the collector on Q2, which is showing almost all of the voltage source. Only about 40mV are dropping across the 4k7 and I'm pretty certain the node isn't shorted to the voltage supply. Wondering why this is.. my circuit is passing signal but it doesn't seem quite like it should. The fuzz on it is crazy! Also, my D2 node voltages differ from the earlier post by E.G.

    Any tips would be greatly appreciated! I am using 5088s instead of 3536, but all my diodes are authentic 1n34a

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    1. Bah! was simply missing the 4k7 from the emitter on Q2. Doh! works great now. awesome layouts on this site - I will try and keep these sorts of comments to a minimum in the future. Thanks!

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  14. I've built/owned/played countless fuzzes and distortions. This one is amazing. Maybe it's just my build, but I love it. About to build another for a friend...

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  15. Can you please illustrate how to wire up a 3PDT stomp with LED for the Octave control?

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    1. I'd like to know how to do this too. Anyone have any idea how to do this?

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  16. Is there a way to add a trimmer to the octave section somewhere to make the octave more pronounced?

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    1. The octave is outta control on mine! Maybe try different diodes? I think I used OA91 for mine.

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  17. my Foxx Tone Machine, built circa 15 years ago, still rocki'n and sounds great :P

    http://s1.postimg.org/4ohr29ka7/IMG_0403.jpg

    2N3565 in this one

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  19. I built this one last week as well as the EA Tremolo. Cool fuzz! It came together and worked beautifully. I used PN3565 transistors, which should be very similar to the original, even the name is almost the same. These are just plastic package transistors. Others may work as well but I highly suggest these. I found them and the diodes on Tayda.
    Photo of it: https://plus.google.com/103511243237729093812/posts/Rjz9AKXPckr

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  20. Hi!For people like me who want to reduce the gain (Sweet and more controllable) suggest you replace 10uf cap on emitter Q3 with 1uf.

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  21. This one is just plain nasty...in the best way possible.

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  23. I have a question about this layout. This shows the 1 of the volume knob in the top left spot of the board. Shouldn't this be going to ground?

    Thanks in advance for any help with this one.

    Brad

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    1. That top left spot on the board IS ground. Notice the two wires that travel down the board - they go to ground, grounding the top row of the board.

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    2. Thanks so much for the reply! I see it clearly now and don't know why this wasn't obvious to me... Thanks again for the help!

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  24. WHAT A TONE!!!!!amazing fuzz tones without the octave up effect, and when you engage the octave up in, it's time for screaming solos! amazing...Built this with 2n5088 transistors!Also log50K pots work great on volume knob!

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  25. Is it normal with fuzz knob at 0% there is no sound? Instead I removed 220r resistor between fuzz 1 and the ground, left fuzz 1 loose and it seems to behave better: it doesn't cut off sound with fuzz knob at 0% but leaves sound with minimal gain. Do you think guys it's reasonable or I am missing smth and it's wrong to leave fuzz 1 loose? I also tried to wire fuzz knob as series resistance and it altered tone but I didn't like the result.

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    1. No, that isn't normal. Something has to be wrong. Check your trace cuts, and make sure everything else is correct.

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  27. I made some mods and my pedal is very loud. I want to make it's maximum volume lower, what's the best way to do it? I tried log pot for vol but it's not satisfactory. Changing Q4 emitter resistor from 1.5k to 5k for example will help with volume, but will it change the tone or smth?

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    1. Changing emitter resistors and other parts deeper into the circuit can possibly change the tone and the operating behavior of the circuit. I built a different fuzz years ago and just recently wanted to reduce the volume as well. I found the best way to do it is to place a resistor between the pedals output and the volume pot (between the 10uf cap and lug 3). If you used a 50K pot, a 50K resistor would half the volume or you can experiment with lower values for less reduction. It acts as a voltage divider before the pot, which is also a voltage divider.

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    2. Cool, thanks for an advice. That sounds pretty reasonable. I'll try that as soon as I get my amp.

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    3. I've just checked it. I used 100k pot for volume and got vol unity at 9 o'clock with stock setup. When used 100k resistor between 10uf cap and vol pot I got unity at 11 o'clock which is better, but with this mod there is significant high end loss and overall tone gets thinner. With 200k (unity at 2 o'clock - perfect) it's even more pronounced. Unfortunately this tone loss can't be condoned.

      Also tried 5k as a Q4 emitter resistor and it help with vol unity, but there's again some impact on the tone, it looses it's bite with higher resistor. Not as bad as with resistor before vol pot, but still not acceptable.

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  28. Built this and added an output boost (LPB-1) so that I could dial back the fuzz and keep it loud. Worked like a charm.

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  30. any ides to make it less synthy and get a softer distortion? changing voltages at Q3 doesn't make a big difference.

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  31. i replaced d2 diode with a link in non-octave mode, but it started to pop when pressing the switch. any idea to prevent the pop? i used it without led and have no idea why it pops...

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  32. I'm really confused by mine. When I first built it, the octave was not very pronounced, so I took some advice from another site and swapped the Ge diodes for Si (Schottke, IIRC). That only helped a little bit. The other problem is that the Octave switch seems reversed. What octave effect there is is only there when the Octave switch is off. Any thoughts on what I might have done wrong?

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  33. I’m having problems with voltages at Q3. I’m reading just over 9v at C, with almost no voltages at B and E. Voltages for the other transistors are in line with those of the GGG voltages. Not sure what I should start checking component wise. The layout and solder joints look clean and correct.

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    1. I’ll add that I have replace Q3 with no change in voltages.

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    2. You can delete these. I mistakenly placed a 1.5k resistor in place of a 15k. Sounds awesome!

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  34. Cool pedal! I used 4x 2n5088 transistors and a 100nF cap instead of 10uF at the output as I had the feeling that there was too much bass. In fact one could even go down to 47nF.

    Very funky sounding and nice octave effekt on higher registers and neck pickup. Might work well for som QOTSA stuff.

    Thanks for the layout!

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  35. How do I add a mid-boost switch on this like that of Danelectro 3699?

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    1. I don't know the Danalectro pedal you mentioned, but I suppose that mid boost is about the same thing of the Fat/Bright switch in the Fulltone Ultimate Octave. In this case you could replace the 3n cap with a 15nF cap or even bigger.

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  36. Troubleshooting my build...I've got very little output and it's clean (not distorted at all). I've noticed that D3 and D4 are "shorted" (i.e. same voltage measured in same direction) but I'm not sure if that's an issue in this circuit. I have also measured the following voltages so I'm hoping someone can point me in the direction of the most likely culprit(s).

    Voltages:

    Supply at board = 9.14

    Q1:
    C = 5.38 (GGG calls for 2.20)
    B = 0.00 (GGG calls for 0.73)
    E = 0.00 (GGG calls for 0.16)

    Q2
    C = 4.77 (GGG calls for 7.50)
    B = 5.38 (GGG calls for 2.20)
    E = 4.74 (GGG calls for 1.60)

    Q3
    C = 6.94 (GGG calls for 7.28)
    B = 0.83 (GGG calls for 0.78)
    E = 0.21 (GGG calls for 0.22)

    Q4
    C = 7.53 (GGG calls for 7.63)
    B = 0.82 (GGG calls for 0.84)
    E = 0.24 (GGG calls for 0.26)

    Any help would be much appreciated!

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    1. Turns out it was a broken leg on one of my 100k resistors. Voltages align nicely now that I have swapped it out for a new one!

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  37. Can I replace 3nF for other capacitor?

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    1. Absolutely yes. With a 3.3nF for a small difference or with a bigger cap for the mid boost mod.
      Try some values, if you can.

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