What the world needs . . .

Started by paul.creedy, April 30, 2019, 01:46:16 PM

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paul.creedy


. . . is a new fuzz :)

I doubt very much that it's even close to a new fuzz really, based on just how many different fuzzes there are, but I made it without full knowledge of all the others and like how it sounds - so until I'm shown that what I've made has already been done I shall consider it mine :)

In a previous thread I posted a picture of the schematic of what I called a Teeny Tiny Fuzz, which was a cut-down circuit from the DE OK (or my Happy Little Accident), this is essentially two TTFs stuck together with a lower power transistor in the first half (because when they were identical it was horribly noisy).

The "Fat" control goes from bright and a little less full through "a bit of a starved sound if you play lightly" to a fatter fuller sound when full up.

The big thing about this is that no matter where the Fat control is, it needs a reasonable amount of signal to work so chugging chords can easily be separated from each other, which is the bit I like about it.

Here's a drawing of the vero layout - I'll have to learn how to do it properly eventually, but for now this is the best I can do ;)



I'm currently calling it a Big Brother Fuzz as it's an extension of the Teeny Tiny Fuzz, until/unless I can think of something I like better.

paul.creedy

#1
I should add that it's currently two separate boards joined with wires, but I do intend* to build it as above and box it up.

*Unless I realise I can't be bothered and just box it up as it is :)


Looking at my own post I noticed that I've put in a cut (the one underneath the link) which would stop it working as there's no earth on the R/H side of it  :-[ and there's an unnecessary cut above it too (oops!).

I'll re-draw it properly at some point, but for now I've made a couple of rough changes to the original picture.

mth5044

Cool, thanks for sharing! Assuming input is Fat 2 and output Vol 2? 1M to ground off input?

paul.creedy

Quote from: mth5044 on April 30, 2019, 04:49:57 PM
Cool, thanks for sharing! Assuming input is Fat 2 and output Vol 2? 1M to ground off input?


yes, although I haven't used any pull-down resistors on any of my builds so far (which might be the reason I get shocks sometimes when swapping pedals about).

mth5044

#4
Besides the added the pull down resistor, it looks to me like this?

EDIT: I'll put this back up when I have time to fix the PNP mistake!

paul.creedy

#5
Quote from: mth5044 on April 30, 2019, 10:39:41 PM
Besides the added the pull down resistor, it looks to me like this?




very impressive :)

yes, that looks spot on, other than the arrows on the two 2N2907s should point the other way because they are PNPs (I've only recently learned this, I'm not speaking from a place of great knowledge)

roseblood11

Looks interesting!
Could you please add a sound file?

paul.creedy


Once I've got it boxed up, will do :)

mth5044

Are all the transistors really facing to the left? If so, it looks like the datasheets for BC108 and 2N2907's would have the emitters and collectors swapped in your layout.

paul.creedy


Quote from: mth5044 on May 01, 2019, 03:24:50 PM
Are all the transistors really facing to the left? If so, it looks like the datasheets for BC108 and 2N2907's would have the emitters and collectors swapped in your layout.


you're right, my mistake one way or another - I do have them all facing the same way on the board at the moment, so the layout lettering is incorrect, but I may well try them facing each other to see what happens ;)

paul.creedy


I shall look a little deeper tomorrow, but a quick bit of experimentation was interesting and shows I've still got a lot to learn, even with the simplest of circuits :)

I kept the same transistors and started by reversing the two 2N2907s, which made things a little less volatile, and at one point (because I wasn't paying proper attention) had the two transistors on the right pointing (flat face) to the left and the two on the left pointing to the right, which made it sound even more starved.

Tomorrow I'd like to try swapping the BC108 for an MPSA13 (which was noisy with them all pointing right) and have the two pairs facing each other, and then have one pair and then the other with one pair facing right and the other pair facing each other.

One thing that is proving puzzling is that in my workshop, with just one pedal plugged into my Roland Cube 30 Bass combo (I use it as a test amp) I'm getting a lot more volume with some of them than I do when I plug into a gap in my ridiculous chain of pedals. I'm wondering if I could do with a buffer of some description in at least one of my builds, or maybe just a small, always-on buffer at the start of the chain.

POTL

fat control will not work well.
I recommend changing it a bit, the diagram below.

paul.creedy

^^^  Maybe something for another day.



I tried all sorts of combinations with the pairs of MPSA13s and 2N2907s and had a lot of fun (and feedback), but eventually settled on a combination I like, which is (right to left on my layout).

BC108 (flat face on the right) 2N2907 left, MPSA13 right and 2n2907 right.

I will amend my original drawing in a bit to reflect this, and I've got some recordings that I'll stick up later (I want to have a play with the transistors in another build first).

paul.creedy


One more bit of tinkering (I've reversed the direction the other 2N2907 faces, so both pairs have the flat sides facing each other).

Here's an mp3 of it - I'm playing on the bridge humbucker into a Boss Katana (clean channel) and changing nothing other than the Fat control from full CCW to full CW.

http://www.arrowheadguitars.co.uk/pics/BigBrother.mp3

I'm thinking of using both the TTF and BB as start points for learning further, so more tinkering to come !

garcho

Quoteyes, although I haven't used any pull-down resistors on any of my builds so far (which might be the reason I get shocks sometimes when swapping pedals about).

Hold up, you feel shocks? or hear them? I don't know what to tell you if you feel shocks, other than you're doing something very wrong.

Pull down resistors bring the stored charge of the input/output capacitors back to zero volts to prevent "popping". There's one billion posts here about it, but long story short, you should always include pull down resistors.
  • SUPPORTER
"...and weird on top!"

pinkjimiphoton

i diggit!

the tune is cool, too

you have some rather misbiased transistors, in a very glitchy musical way it almost swells in backwards - like.

please be careful with your power supply , if you're being shocked you have a grounding issue

plug in your audio cables before powering up may help
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