Blast from the past.... Brontoboost

[aron]

I think I will take my Brontoboost out tonight on the gig. Gotta find a center positive adapter or use a battery!

[John Lyons]

Anyone herad from Joe?!
He's off the map as far as I can tell.
Non responsive to all my communications

[aron]

hmmm I might not be able to use it. If I turn the treble control to the right, I get massive hiss. I need to open it up. It's practically all white noise.

[aron]

I don't see it. I can't figure out what is hissing. If I turn the tone to treble boost, then from what I can determine, I have a 2N3906 buffer (no gain), into a highpass filter->output stage (which is a Ge transistor boost). However the way it is hissing, it's almost like the 2N3906 is doing the hissing. It does not boost though. The only thing I can imagine is that at some point the pedal was reversed biased and per R.G.'s article, the buffer is now noisy??

AFAIK it has always been run on batteries.

http://sounds.ampage.org/files/BRONTOschemV3.0.gif

[aron]

R.G. or anyone else - if a transistor is reverse biased, is the hiss enough to cause this buffer to become a hiss generator? What I am asking is since it doesn't add gain (although the next stage does), can it hiss enough to cause this?

[aron]

audio probe I guess.....

[davent]

Anyone herad from Joe?!
He's off the map as far as I can tell.
Non responsive to all my communications

Hi John,

Looks to still be active at youtube, have  you tried contacting him there?  http://www.youtube.com/user/joegagan

Take care,
dave

[John Lyons]

Just tried...we'll see.

thanks Dave

[joegagan]

hi guys. i talked to john l, just now, he told me about this thread.

aron, the most common cause for hiss in those brontoboosts was the germanium tranny being bad. i would try replacing that first to see if that cures it. for your raplacement trans, the higher the gain the better for the bronto.

i would also be curious to see if your reversing the power supply theory ends up being a factor.

nice to see the site is still alive and going great!

[aron]

Cool thanks. It's just weird that I don't hear the hiss when the tone knob is to the "left" as in full frequency response mode.

Hope you are doing fine!

Aron

[DougH]

Funny, Aron... You got me curious about trying mine again. But the DC jack apparently only works with "-9v". And I don't have any 9v batteries lying around anymore. I guess that must be a milestone of some sort... 

I'm going to give it a try when I get a battery again.

[aron]

I just fixed it. It was the ge transistor. I have tons if npn ge, but very little pnp. I found an old small bear one and it worked. The holes in the pcb are really small. I used a socket so I can swap it out later.

[joegagan]

that is good news. hi doug!

[aron]

Now all I have to do is go to the flea market and get a few DC adapters for use with positive ground pedals.

[joegagan]

aron, i remember you had a lot of npn germaniums a long time ago.
i found a stash at the local surplus house ( every once in  while a new box emerges from their depths in the back) of AC187s, npnge. they test out pretty good.

i am curious to see if you can get anything useful out of the bronto. it is sort of the opposite of your taste as i recall. as a fuzz it is quite compressed and mushy ( which i like). as a boost ,it works well. but it does not have enough of it's own smooth gain like we are used to with a tubescreamer to do a mainstream rock distortion on its own.  it is like a boost or fuzz for grungers.

let me know what you find, please.

[aron]

I liked it but it was too bright to use last night. I need to make the pedal that I've been thinking about for years. It's a pedal that will work for all fuzzes etc...

Yes, I do have some of those NPN Ge left. I would have to change the circuit and I didn't want to do that. Easier to buy a single adapter for it.

[joegagan]

yeah, that was the prob with that pedal. it worked great for me in my live rig because i would leave it on all the time. usually use two, one for fuzzy and one for bluesy boost. so my tone controls  on the amp were set accordingly. hence the later tone dog mod that allowed tailoring of the high end at two points in the circuit.

but in defense of the original design, i really like that full spectrum signal hitting the preamp tubes. it gives a clarity when turning down the guitar ( or using your fingers with a lighter touch) that gives a very wide clean to dirty range in a natural way. many people have told me that the bronto is the most touch reactive pedal they have used.

[aron]

I like that full spectrum too, I have a Shaka Pedal that does clean to overdrive really well. I can pretty much play the entire night with it on. So it's a similar thing, it's just that lately if I do play some funky stuff, I've been getting into a little more highs. The pedal does sound good now, the treble boost is working too.

[joegagan]

oh yeah, i remember the shaka series. which version are you using?
also, a video i did yesterday to illustrate some of how i use it: pardon the camera mic, i think i blew the diaphragm!
http://www.youtube.com/watch?v=NcU59u18f44

[aron]

Very close to the Shaka HV but I've been modding it for myself for years. I have two of them. One has stacked ICs and mostly filtering changes. The other has variable bias of the FET.