Octave/supersaturation on Fuzz Face circuit

[joelap]

Hey all, I have been toying with the concept of adding an octave up effect to the output stage of a Fuzz Face circuit.  I breadboarded it up, and used a 10uF electrolytic as the output cap of the Fuzz face circuit.  Then, I used a 42TM018 1:1 transformer and used 2 Ge diodes off the secondary side (center tapped) a la octavia.  The sound was very interesting... it did produce a semi-octave up effect, though not as pronounced as I had initially hoped.  Also, the sound became super saturated... I generally consider the FF a tame sounding fuzz, but this brought it a bit closer to the untame sound of pedals like the octavia, fOXX tone machine, etc.  My only complaint is that there is a volume drop with the transformer and diode pair switched in the circuit, even though the transformer was a 1:1 ratio.  If you've got a chance, try it out yourself... tell me what you think.  I rather like the sound a bit... just wish it wouldn't have the volume drop so I can box it up with two stomp switches.  I guess I'll add another gain stage to boost up the signal a bit before hitting the transformer, which I'd rather not do.. maybe its the DC resistance/reactance of the 42TM018 that is causing the volume drop?  If so, maybe I can find a 1:1 transformer with a lower DC resistance...  I'll post back if I find a solution.

Anyone try this?  Give it a shot, you might like the results!

Joe

[petemoore]

  Take a look at the Octo-Booster, it's on my 2nd pedalboard and is #1 octave effect I go to, needs a FF, TB, or somekind of Fuzz to make it light up, lights upoctave really well. It's just 1 biased mosfet more than what you have there really.

[joelap]

I tried using the octobooster with a BS170 into a 42TM022, but it didn't work.  I dont have a 2N7000 on hand... I was going to try a 2N5457 stage.  I was hoping the 1:1 transformer would preserve the signal strength, but it didnt.  I might try a 2N5457, and if that doesn't work, I'll see if I can grab some 2N7000's cheap somewhere. 

[jaytee]

With a 1:1 centre-tapped transformer you will get half amplitude out because you are full wave rectifying it. Try a 2 or 3:1 transformer or take the output from the collector of the second transistor.

[petemoore]

BS170 into a 42TM022
  BS170 into a M42TM018 is working here.

[joelap]

Hmmm.... perhaps I got the pinout wrong on my BS170 then... I have at my disposal a 42TM018 and 42TM022 and neither one worked with the octobooster using a BS170 off the output of the Fuzz face.

Also, in the octobooster, is the primary the side with the diodes, or the circuit side?

EDIT: aha!  Pinout was wrong!  I was viewing it as DSG like my J201's are, when in fact the BS170's that I ordered are DGS!  ( http://www.fairchildsemi.com/ds/BS%2FBS170.pdf )

I'll give it a shot in a couple of minutes, and repost!

Side note: Anyone else love using Fairchild's transistors and FETs?  I have had nothing but good luck with their components... and usually they're the cheapest on mouser as well.  Their datasheets are always clear too, even to less experienced guys like myself.

[tcobretti]

I hope the octobooster works for you, I like it quite a bit, and I am very pleased you are still using it Pete!

You can box your OctoFF with two switches; just add another volume pot after the transformer.  Then make the switch a DPDT that switches between the output pot of the FF and the output section of the OctoFF including the pot. 

Like this:



You might want to put the switch before the output cap, include the output cap in with the output pot, then put a really big cap on the octave side, like 100u.

I hope that makes sense.

[joelap]

Well, on breadboard placing the octobooster after the fuzz face induced quite a bit of squeeling at higher settings on the fuzz pot... When rolling  back the fuzz I can tell the tone is there, but the squeels were huge.  Its probably because it is breadboard.  I might end up buying a few transformers from mouser and seeing if I can find one that'll step up the volume... I like the tone I was getting without an additional stage boosting into the transformer, but the volume was about half what it was with the transformer and diodes switched out of the circuit.

[tcobretti]

The octobooster should be before the fuzzface.

[joelap]

before? ... hmm... I was treating it like an octavia... seeing how the transistor and diode pair is the last "ingredient" in the octavia, i figured I'd put it after.  Thanks for the heads up, I'm not sure how I missed that after reading through all the threads about it 

Well, it's getting later here so I'll move the octobooster's parts before the fuzz face and report back tomorrow.  hopefully I can get it done before I have to leave for classes, so I can give it an appropriate runthrough.  Otherwise it'll be on my mind from 10AM until I get home at 7PM... and I really have some work I've gotta do tomorrow.

[joelap]

ok, I tied it out before the fuzz face earlier today.  I used a 10uf electro input cap, into the bs170 stage.  then another 10uf elecro into a 42tm018 tx, 2 1n34a ge's and straight into the 1uf input cap on my ff cct.  AWESOME SOUND!  I'm thinking the transformer plays  a huge role in the sound, as i tried a 42tm022 in this situation and it didnt sound as good.  might also try lifting one of the diodes for a total of three modes: classic, supersat, octave.   NICE sound, i like it more than my octavia that i previously built.  all around awesome sound!

[caress]

did you try simply adding a recovery stage after the transformer in your earlier setup?  mosfet or if you're doing pos ground a ge boost?

[tcobretti]

I'm glad you like it!  One of the great things about the octobooster is you can use it with almost any fuzz or distortion and turn it into a octave pedal. 

You can even use it by itself.  I would certainly put a volume pot after the diodes in to give you control of the boost.

[joelap]

I was going to put a volume control, but by using a 42TM018, it seems the volume with the octobooster in is the same as the volume with it out (using a master volume at the end of the fuzz face).

[tcobretti]

The fuzz flattens out the boost but gets more distorted as a result.  If you want to use the OB by otself or with another fuzz, a volume control is a good idea.

[petemoore]

I hope the octobooster works for you, I like it quite a bit, and I am very pleased you are still using it Pete! 
  Heavy octave.
  Sounds weaker than the Green Ringer by itself, a little wierd, cool.
  Needs at least Pre Boost, sparks it up, Then Fuzz after works neat tricks.
  Pre-Fuzz makes it Octavious.
  I have it to where I can
  Octo.
  Boost-Octo
  fuzz-boost-octo
  Fuzz-octo
  fuzz-octo-boost
  disto-octo
  dist-octo-boost
  Boost dist octo
  ...it's in my new Montezuma-Octo box, thanks to Dragonfly and Tcobretti !!!
  FF Rat and MiniBoost
  ZW Montezuma and Tri-boost
  Octo....plenty of options, such as using his volume control as a cut [for recovery later] or boost [for later cut]...
  Easily sets up to go from Fuzz to wonderful OctaFuzz w/Octa switch [only 1 hit] that's what I prefer.
 


   
 

[joelap]

New development: using the Octobooster before the fuzz face.  If I strike a power chord harder than normal, the sound actually drops out and fades back in.... weird!  Anyone have that experience?

[tcobretti]

I don't understand the electronics of it, but too much gain can cause that to happen.  If it was irritating, that is where the octo volume pot would come in handy.

[joelap]

I don't understand the electronics of it, but too much gain can cause that to happen.  If it was irritating, that is where the octo volume pot would come in handy.

hehe... you're going to get me to install one yet!     OK OK... I'll start with a trimpot first... I'll give in   

[tcobretti]

Victory is mine!