Electra Distortion/Bazz Fuss hybrid?

[black mariah]

I was just looking at the Electra Distortion circuit and wouldn't you know it, it's basically a Bazz Fuss. Or is the Bazz Fuss basically an Electra Distortion? :? Chicken and egg questions aside, has anyone done a bastard mutant of the two? What I'm thinking is use the diode off the collector and the Darlington pair from the Bazz Fuss, but with the clipping diodes like the Electra Distortion. With the limited knowledge I have I'm expecting a psychotically fuzzy sound, but is that anything like what I'd get? Feel free to punch me in the face if this is stupid. If nobody's done this before (yeah, right) I'll get right on it, but if I can save time and parts by just asking here... :lol:

[black mariah]

Is it THAT stupid? :shock:  

[brett]

I was just looking at the Electra Distortion circuit and wouldn't you know it, it's basically a Bazz Fuss. Or is the Bazz Fuss basically an Electra Distortion?  

Well, as far as I can see, there's not much of a similarity between the BF and the Electra.  (except maybe in parts layout??).  One clips by diode feedback, while the other clips the output.  The BF is high gain, while the Electra is low gain (but can be changed).

If you might see some cool hybrid possible in there, let us know.

BTW, if you're after a really cool BF, I suggest you look at the Whisker Biscuit.

cheers

[black mariah]

Yeah, what I meant to say is that their layouts are practically the same.

I got bored and boarded it. All the diodes are 1N4148, the transistor is a 2N5210. I initially used a polarized 10uF input cap, but the sound was quite muffled. A switched to a .047 brightened things up considerably. Distortion-wise we're talking Bazz Fuss levels but with a softer edge to it. It's not as harsh as a 'standard' BF.

The only problem is that the note decay is horrible. About how many volts should I be reading at the collector of the transistor? I'm getting .73V at the collector and .53V at the base, with .1mV at the emitter. Too low? Too high? Would using a smaller resistor into the collector improve matters? Will Rocky defeat Boris in the 'round the world airship race? Find out next week in "Bad News Bares" or "Rocky Mountain Low".

Guh... I watched too much Bullwinkle when I was younger...

*EDIT*
Already tried the Whisker Biscuit! Gary from ROG sent me some proto boards he had laying around and that was one of them. Great sound. It's actually housed in my Big Muff enclosure. Sounds way better than the BM ever did. :twisted:

[Marcos - Munky]

I believe the only hybrid possibility is to have a gain stage with a clipping diode between base and collector of the transistor and two clipping diodes in the output to ground. The Whisker Biscuit rocks. I built one, then traded for a Ibanez Fuzz, and now built another one, that is on in almost everytime .

[Elektrojänis]

I've just been testing some stuff with with Bazz Fuzz... Try different resistor values and different transistors (you can also build your own dalingtons from two normal transistors). Try different diodes too (I liked 1n4148 most for the thing I was after).

The note decay will probably never get really clean but you can make the sustain longer by tweakking the part values etc.

I ended up driving mine with a simple fet booster... Enough sustain to get away from the note decay problem. (And I wanted nastier higher gain sound anyway.)

Edit: I ended up with 0.047µF cap in the input of the BF circuit too.

[black mariah]

You know how Big Muffs and the Whisker Biscuit both have a sort of 'sputtery' high end sometimes? That gnarly razor-edged bite? This doesn't have that. So now I just want to go about getting the decay smoothed out.

Driving it with a booster? It would be easy enough to just tack a simple booster onto the front end of the circuit. I may give that a shot later.

While I was at Radio Shack yesterday I picked up a small (4x2x1) plastic enclosure. I somehow managed to fit the board for this thing, the battery, and two jacks into it. There's still enough room for either a switch or knob. Scary cramped. :lol:

[brett]

a 2N5210

Hi again.  You'll probably need to bias the collector up from its present voltage.  You might consider replacing the collector-base diode with an led or two 1N4148s in series.  Also, make sure you've got a cap between the collector and the 2 diodes that clip to ground.

good luck

[black mariah]

Stupid newbie question... how do I go about biasing the collector up?  :?

I'll see if I can squeeze another 1N4148 in there. I have everything in that area way too tightly packed.

[brett]

Apologies BM for writing jargon.  :oops:   First, some explanations.  You can think of a transistor as a kind of valve.  The rest of the analogy gets pretty unrealistic, but it's very simple.  Somebody please correct me if I'm wrong about this.    The transistor base is like the handle of the valve - it controls the flow of current between the collector and emitter.  The voltage is like the pressure in the system.  Usually you want more than 1 V on the collector, because that's like very low pressure (the base-emitter needs 0.6V to work, so the collector can't go anywhere near as low as 0.6V).  How to get more voltage there?  Easiest way is to replace the feedback diode with a resistor (usually a large value - say 220k - you could use a 500k pot to find a good value than replace it with a fixed value).  What this achieves is having the transistor "turned on" just the right amount, so that the pressure differences (ie voltage) are divided nicely between the collector resistor and the transistor.  You'll find that it sounds good with a couple of volts on the collector (for example 7V across the resistor and 2V across the transistor).  After that, I'm fairly certain that you could add the clipping diode back in (in series with the bias resistor?).  There WILL be some weird interactions between biasing and how much clipping you get, but that's some of the fun.  :wink:  

Hope that helps.

The Bazz Fuss was clever and unusual in that it used a Darlington pair of transistors, and biased the pair with a 1N4148.  I have difficulty getting my head around that scheme most times. :roll:

[Elektrojänis]

Hmmm... Now I remember couple of things for getting more distortion out of electra circuit.

Try adding 10µF cap from the emitter to ground (parallel to that 680ohm resistor). I had actually forgotten that it was not on the original schematic. You can also use smaller cap to voice it for having some treble boost instead of full range boost. I'm not totally sure but something like 0.33µF might give a frequency responce that is bit like Tube Screamer.

Then check out Joe Davissons easydrive too... I haven't actually tried it myself, but I think that the two resistor and a capacitor -feedback arrangement is used for getting more gain (less AC feedback).

Hmmm... BTW... That 4x2x1 is in inches right? Here is the fet booster into BF thing I was building: http://www.hut.fi/~pjunno/temp/lakerol.jpg

The enclosure is a small candy box. It is about 6cm x 6cm x 2cm.  In inches it makes something like 2.36" x 2.36" x 0.79". No swich, but I managed to get a volume pot in there. Plugs right into the guitars output jack.

I've built a few electras in the same kind of enclosures, but it was never this tight as this one is a two transistor circuit.

[black mariah]

Brett, no need to apologize, you have just increased my undestanding of transformers (and circuits in general) a thousandfold.  :lol: I have a lot more room in this box than I should have, so I'm going to wire a pot in place of the collector diode and fiddle around with it. Let's see how much I've learned here. If I replace the resistor going to ground off the emitter with a pot, it should act as a gain control shouldn't it? Or am I an idiot? :lol:

Elektrojanis: Thanks for the info. I'll be sure to toss a cap on there. More gain is ALWAYS welcome. Yeah, that's 4x2x1 inches. It's quite surprising how much room that is if you plan everything right. By feeding the pots out the ends instead of the top, I'll be able to add two pots and still have room for a footswitch. :shock: I don't think I'm going to do the footswitch though. I already have too much crap to unhook if I want to modify the circuit as it is. :lol:

[Elektrojänis]

I recorded some samples of my fet booster into Bazz Fuzz thingy. I think I will call it Aggressor if no one has used that name for a pedal yet. I might even draw a schematic for it too.

Anyway... Here is a picture of my unit (cant relly call this one a pedal): http://www.hut.fi/~pjunno/temp/aggressor/aggressor.jpg

Then a soundsample through my selfbuilt cabsim: http://www.hut.fi/~pjunno/temp/aggressor/aggressor_cabsim.mp3
(Aggressor - Cabsim - Soundcard)

Another soundsample through my small lm386 based amp: http://www.hut.fi/~pjunno/temp/aggressor/aggressor_kompshall.mp3
(Aggressor - Amp - Mic - Micpreamp - Soundcard) There are 3 different tone control settings of the amp used in this.

Its very grindy and trashy...

[black mariah]

Just finished up some work on this thing.

I added a 100K pot in series before the collector diode. It's quite interesting. At one end you have a very bright and crackly tone, at the other it's just slightly less bright but with considerably more body on the low notes. Almost like a thickness control. I need to pick up some small bodied 500k pots and throw one in there. That ought to change the tone even more. I added a 10uF cap off the emitter but all that did was practically kill the signal. Adding a 470k resistor in paralell brought the volume back up, and smoothed out the decay. Woohoo!

I do have another issue, unfortunately, and that is that I think this would sound much better with single coils than it does wit humbuckers. I can't test this out since I don't have any guitars with single coils in them. Is anyone with a tele or strat willing to put this thing to the test for me? It's super simple and sounds good! As far as you know... :lol:

[brett]

Glad to hear that you're having success!!

I added a 10uF cap off the emitter but all that did was practically kill the signal.

That cap should run PARALLEL to the emitter resistor.  And with the +ve end to the transistor, -ve to earth.  It'll boost your gain by several times.  

cheers

[black mariah]

That's how I have it running, as this lovely diagram shows!



I may have the output diodes reversed on the schematic, but they're the right way around on the board... whichever way that is. The resistor/cap combo off the emitter actually seemed to kill some of the distortion. Maybe I'm just imagining things. Whatever. It sounds better the more I mess with it, but I'm running out of board space. I have it cut down to 2x1, or thereabouts, in order to get it to fit in the box I'm using. I think this is the end of the road for this build. The Uglyface beckons. :twisted:

[christian]

bm:
Is that really 470k resistor from emitter? Should it be 470 ohms?

[black mariah]

Depends on your preference. I just tried a 680 in place of the 470k and found way more distortion, but the note decay is back to sucking. I'll try out some intermediate values tomorrow and see what happens.

Also while I was in there, I added more diodes after the pot. I had one already on there, so I installed another. Then two more. I'm going to whip out some toggle switches tomorrow and make all those diodes, plus the output diodes, switchable on/off. Yes, I am a very, very bored person, but I'm learning so why not? :lol:

[brett]

Hi.

Yes, I am a very, very bored person, but I'm learning so why not?

And, yes, you've definately done something interesting.  Changing that emitter resistor from 680 to 470k has probably changed the bias on the transistor from one extreme to the other.  Have you tried an intermediate value?

Cool circuit.  Individual and non-conformist. :twisted:

cheers

[black mariah]

Craptastic news! I found a schematic that's pretty much what I've been doing. :lol: You can find it under "Electra Variation" right here: http://www.generalguitargadgets.com/v2/richardo/perfboard/index.html

I'm done with this in its current version. What I'm going to do as soon as I get some more parts is redo this as a more focused project. It occurs to me that with a few tweaks this could be a very nice boost/fuzz hybrid. I have a few ideas already, so let's hope they work out.