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BEE BAA


 
9/2/2000 5:29 AM
Gord BEE BAA
Hi,  
 
You remember the Guitar Player magazine issue a few years ago with the 'Stompbox Stampede' article? I was flipping through it and they really seemed to have loved the Roland BEE BAA pedal. These are my questions about it:  
 
-has anyone tried it? How does it sound? Maybe like a BMP?  
-Is R.G.'s schematic of it good? (I assume it is)  
-Can I simplify it? There seems to be a lot of fat that can be cut out of the pedal.  
-would it sound better if I wired the second transistor after the third or the fourth after the first? (just kidding)  
-Maybe I should make a BMP with the gain stages set up like this pedal. Yes? No?  
 
Thanks  
 
Gord
 
9/2/2000 6:06 AM
Gord
Whoa,  
 
I just looked at the schematic.  
This is what I gather:  
 
-Get rid of the boost function  
-Get rid of the tone select switch  
-two gain stages, not four as I previously thought  
 
Which tone select position is the better sounding one?  
 
People on the net sell these things for big bucks. I could buid one with MPSA18s for peanuts......  
 
Gord
 
 
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9/2/2000 1:24 PM
Gus
email

Gord I have not built the effect yet but a friend has played one and likes it. How I would build it: the dist is setup as 2 high gain transistor stages I think any trans Hfe >200 would be OK the bias net work is temp stable a very constant. I would build a IC noniverting input buffer or with a gain control gain of 1 on up I would us a 100k lin VOL pot on the output of the stage into the two dist stages the stages input z is low so the lin pot should have a nice taper after the dist stages I would place a tone network etc into a buffer could be the other half of a dual opamp
 
9/2/2000 7:27 PM
friday
email

Gord,  
I don't know why the Bee Baa is so special but for me it really is a first class fuzz. I think that the Bee Baa has better harmonic definition (less gain stages perhaps)than a Big Muff and is easily as fat sounding. There is a sound sample over at Tonefrenzy.  
I have the original Roland unit, I plan to build a simplified version of it, it sounds like you are on the same path.  
My simplified unit would just have the "full range fuzz" with true bypass. The mid range fuzz and treble boost are decent but pale in comparison to the full range fuzz.  
R.G.'s schem is right on, the 2sB828's are available (I forget where). This pedal is simple, but heartily kicks ass. I love it with a wah in front.  
I haven't checked the schem recently, I wonder how it compares/differs to a silicon FF?
 
9/2/2000 10:40 PM
Gus
email

It is not the same as a FF. the bee baa dist stages are are two emitter bypassed gain stages. A grounded emitter stage is a max gain type stage but it is not temp stable the emitter R is a form of feedback that reduces the gain of the stage however if one bypasses the emitter r with a big enought cap it will be a max AC gain stage. From the art of electronics book if the collecter is at 1/2 supply voltage the gain will be 20xsupply voltage for small signals however if the collector is closer to ground (NPN) the gain goes up and the dist should change with signal level(maybe this is what people like). When I first saw the R.G. schematic it did not look like a big deal however a good friend of mine played and told me it sounded very good. It should be more nonsensitive to transistor type than some other fuzzes it looks to be designed for Si transistors to me. I would try R.G.'s favs or 2n3904,PN2222a,MPSA18 etc. BIG HINT try building some fuzzes with Power Transistors TIPxxs are fun Larger Die Size sometimes means lower noise and lower gain and less high end some of the things Ges are good for might be fun as the first transistor in a FF type circuit Hint Hint  
 
You also might want to try the schematic I sent Aron Another Sick Fuzz the distortion stage can go from sick gated to smooth  
 
Gustav Smalley
 
9/3/2000 6:34 PM
friday
email

Thanks for the analysis Gus. I looked at the schem and realized that it is quite different than the FF. I also should point out that the original xstrs are 2SC828 not 2sB!  
Thats an interesting concept about using the power transistors.
 
9/4/2000 3:08 AM
Bart
email

Gus,  
Have you found any particular TIPxxx that get in the majic 85 hfe range for the first stage of a FF?  
Bart
 
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