old RCA trannies sweet in bazz fuss

[CoolJohnny]

chopped up a waterlogged old heathkit stereo receiver, and found at least twenty germanium diodes, scads of .01, .02. 047uf caps, and a half dozen of these metal can rca trannies. germanium i can only assume.

all of them had four leads, marked on the cicruit board as "e, b, c," and "s." first three are obviously emitter, base, and collector, fourth one must be source?

i just bent that one out of the way and they sound sick in my bazzfuss. a real midrangey ring, low-end woof, and plenty of crystaline highs. at lower gain settings, the decay is kind of gated like many ge circuits, but putting this thing between a strat and a bassman really made the neck pickup sing almost (emphasize almost) like a humbucker.

also found in there a couple of metal can 10-pin ICs that i have not extracted yet, any ideas?

[ambulancevoice]

all of them had four leads, marked on the cicruit board as "e, b, c," and "s." first three are obviously emitter, base, and collector, fourth one must be source?

"s" is most likely shell as in the enclosure of the transistor
usually, the case is connected to e or c, on some transistors it isnt, so an extra lead is added that is just connected to the case, when this lead is grounded, noise is reduced
source is only of fet transistors btw, not bjt's

oh, and any chance for a soundsample? or some pics?

[CoolJohnny]

aha. so you're saying if i hadn't clipped those "s" leads off i could've grounded them and improved the noise situation in my circuit. i did notice a slight increae in noise but its honestly not something to concern myself with. good to know for the future though. any ideas on those ICs i mentioned?

regarding pics or clips, wow. sad to say im pretty old school in that i don't have a good enough computer setup to do stuff like that. though i will be selling some stuff on ebay in the near future and will no doubt need some pics of that stuff, i guess i should join the last century and spring for a digital camera...i still shoot concert photos on film for the stories i write.

the best description i can give is that it sounds kind of like a good fuzzface; you know that fat roughness, but with a bit more of that singin' mid-range thing and a little more definition.  turning down the volume knob on the guitar gives some results similar to what you'd hear doing the same on a fuzz face.

im a big fan of early fleetwood mac (okay, and what the hell the later stuff as well) and until i put these suckers in the bazzfuss i've never been able to really nail that "then play on" tone that peter green and danny kirwin got on those side two jams.

[ambulancevoice]

aha. so you're saying if i hadn't clipped those "s" leads off i could've grounded them and improved the noise situation in my circuit. i did notice a slight increae in noise but its honestly not something to concern myself with. good to know for the future though. any ideas on those ICs i mentioned?

regarding pics or clips, wow. sad to say im pretty old school in that i don't have a good enough computer setup to do stuff like that. though i will be selling some stuff on ebay in the near future and will no doubt need some pics of that stuff, i guess i should join the last century and spring for a digital camera...i still shoot concert photos on film for the stories i write.

the best description i can give is that it sounds kind of like a good fuzzface; you know that fat roughness, but with a bit more of that singin' mid-range thing and a little more definition.  turning down the volume knob on the guitar gives some results similar to what you'd hear doing the same on a fuzz face.

im a big fan of early fleetwood mac (okay, and what the hell the later stuff as well) and until i put these suckers in the bazzfuss i've never been able to really nail that "then play on" tone that peter green and danny kirwin got on those side two jams.

sounds nice!
ive got some russian germs with the 4th pin, i might try them in my bazz fuss
also, those germs are probably fairly low/mid gain
so the case ground/noise reduction thingy might not be totally neccesary, unless you put a boost in front of it
which would increase the signal gain and add noise
well, im glad this thing with germs works well
i saw this in the gallery ages ago too
http://www.aronnelson.com/gallery/v/Schematics-etc/lowboy.gif.html

[CoolJohnny]

well, that looks interesting. i've seen the "trim between two transistors" thing before but have somehow never had much luck with it. and the rest of that circuit is basically the bazzfuss.

in mine, though i used a 47K resistor to the power supply. can't remember the effect of other values specifically, but beforei build anything a ibreadboard the shit out of it for weeks, changing every possible component, so that must have been the best choice. i keep telling myself i need to make notes when i do these things.

if you build this, please post results...

[ambulancevoice]

well, the idea behind the lowboy is because that the bass fuzz uses high gain transistors, and germaniums are mostly low/mid gain, the germs need a gain boost, so in order to increase the gain, they are put in a darlington configuration with a high gain silicon transistor, or another germanium can be used. that trim pot is most likely a bias control

in my build, ill probably add a collector bias control, since this bass fuzz could probably be tailored to sound better or completely different merely by adjusting the bias rather than having fixed biasing.
plus a fuzz pot

[JDoyle]

The 's' stands for the substrate, the p-doped slab of silicon that the n-doped collector, the p-doped base, and the n-doped emitter (for an NPN, which I'm certain it is, diffused PNPs were horrible back then) are difussed into. In the future, don't clip it and be sure to connect it to the lowest voltage in your circuit because it can form a paracitic PNP transistor (it is the collector, the NPN collector forms the base, and the NPN base forms the emitter), and it does help with the noise by isolating the other doped areas.

Those 10-pin can ICs? I can't help, and I doubt anyone could, until you let us know the markings/numbering on them. Honestly, I think you may have some cool chips to play with so let me know!

Jay

[CoolJohnny]

here's whats in this thing, marked 4/5/76

two 10-pin metal can ICs with coding as follows; RCA 417 123 949 OG, RCA 417 123 004 OL

four small four-pinned tansistors (two of which are used in the bazz fuss as described above) marked; RCA 133 FA 1H

a half-dozen larger three-pinned transistors bearing markings as follows; all RCA 417; 136 CG IG, 137 CK  1H, and 138 CK 1F (most of these are very well heatsinked).

any ideas from the crowd?

[mac]

well, the idea behind the lowboy is because that the bass fuzz uses high gain transistors, and germaniums are mostly low/mid gain, the germs need a gain boost, so in order to increase the gain, they are put in a darlington configuration with a high gain silicon transistor, or another germanium can be used. that trim pot is most likely a bias control

in my build, ill probably add a collector bias control, since this bass fuzz could probably be tailored to sound better or completely different merely by adjusting the bias rather than having fixed biasing.
plus a fuzz pot

See my post:
http://www.diystompboxes.com/smfforum/index.php?topic=60531.0

I strongly recommend to add a trimmer at the collector in all bazz fuss to find the sweet spot.

mac

[ambulancevoice]

yeah i saw that ages ago
remember? i thought you got the idea for the diode between the transistor from a post i did before that one

[mac]

i thought you got the idea for the diode between the transistor from a post i did before that one

Yeap, but I did not bookmarked it. Can you post the link, please?

mac

[ambulancevoice]

http://www.diystompboxes.com/smfforum/index.php?topic=60900.msg477690#msg477690
scroll down a bit to see a schem

[mac]

 

mac

[ambulancevoice]

yep
turns out i posted that after your post about the germ bazz fuss