Red Fuzz Build Report... Kick A$$!!!! - Part 2

[arma61]

Hi all,

about Buff'n Bled, is it possible to "cascade" them? , so you can mix two FXs and a clean signals? or, as usual, there are problems with impedance, tone sucking and so on.

thx
Armando

[Mark Hammer]

You can most certainly stick two pedals in series in the loop.  Just think of it as one big effect that happens to be divided into two boxes.

The one thing you may need to be mindful of if you do so, however, is that the level of whatever is coming in to the blend pot via the loop should be somewhere in the ballpark of whatever comes in via the clean side of that blend pot, or else you'll find yourself needing to futz around with the red "mystery resistor".  The other thing is that two pedals in series poses a risk of hiss, especially if you have one high gain thing into another.  Panning between clean and effect will start to feel like panning between quiet and hissy.  If that's the case, you can stick a small value cap (e.g., 220-1000pf) between point B on the diagram and ground.

[arma61]

thx MarkH for the answer, may be I've used the word "cascade" improperly, what I mean is to have two separate FXs that will be "blended" with the original guitar's signal, so  as an example, not a fuzzed sound being "reverbered", but 3 separated single signals mixed together. I've already started a topic about this (see http://www.diystompboxes.com/smfforum/index.php?topic=60117.0 by the way I'm still waiting the mixer to arrive!), so I though, with an easy building like this, it should be possible to achive the same result, but I don't have a clue on how to do this, though, looking at the schem. a little better now, it seems there's no way, it's build just for 2 signals and my idea of a mixer is still the more feasable, isn't it?
thx
Armando

[Mark Hammer]

What you really want, then, is a simple mixer that would let you blend variable amounts of 3, 4, or more signals to one mono output.  Many of the circuit collections on line will have something like this, as will the various Ctraig Anderton books.

[arma61]

thx MarkH. that's what I thought at the end, so I just need to wait for the mixer to arrive!.

[Cardboard Tube Samurai]

Excellent! Now back to my question...

[Barcode80]

to answer the ? about the blended signal at lug 2, that goes straight to the output...

[Cardboard Tube Samurai]

Sorry, been out of town for a few days and only just got your post this afternoon. I've now got sound and blend happening (turns out I had 2 resistors in the wrong place), but I'm getting crazy oscillation if I have more than around half volume or if I blend 100% of the effect. Can anyone shed any light?

[Barcode80]

wiring problem somewhere, generally it has been my experience that oscillation while blending means that somewhere the output of the clean is routing back through the effect again, causing infinite feedback...

[Cardboard Tube Samurai]

Dredging up an old topic here...

So I got those other problems sorted. Turns out that in that schematic for the BnB where it mentions the optional resistor, you're probably better off using a trimpot. I was using a resistor from the recommended range but it was still too high, hence why none of the effect was getting through. The other problems I encountered resulted from me trying to fix that problem elsewhere, but that's a long story.

Anyway, to the point of why I'm dredging up the old topic... I have built the BnB in it's own enclosure but now I am finding that I am getting switch pop from any of the effects that I am blending it with. I know it's just a matter of a resistor to ground somewhere in the BnB, but to save me some headaches, can someone please give me a bit of an idea where and what size? I'm guessing that I put it just before the blend output, but that is indeed just a guess 

[Barcode80]

i would but a 1-2M from input of the effect side of the circuit to ground, same on the output side.

[Cardboard Tube Samurai]

Cheers, I'll give that a crack!

[Cardboard Tube Samurai]

No dice! Maybe I'm confused by what you mean... Can you please re-word it? I'm feeling pretty docile right now

[Barcode80]

i was saying put a 1M from the tip of the effect send in the schem to ground, same on the effect return side.

[m-theory]

I love my red fuzz...one of my favorites. 

[mac]

I suggest to use a MPF102 or BF245C that have higher Vgs than J201 or BF245A. Also replace the crappy 10uf electro cap with a  poly cap, or a 10uf tantalum with a 0.1 poly in parallel.

Before building it I tried a 741, but jfet input opamps like TL071 or LF351 are better in this circuit.

Just a little drive, a little high cut and volume above unity gain and tubes scream. I love this pedal.

mac