Jordan Bosstone Build Report (Pics Added 8/1/06)

[Paul Marossy]

I made a PCB for it and etched probably last year, and I wasn't that impressed with it - it just didn't sound good. I stumbled across it yesterday in "my boneyard" and revisited it. I found that it sounded bad because I used an NPN for Q2 instead of the PNP that it was supposed to be. Doh! Once I put the PNP in Q2 position, I found out that it really can rock.

Mine's slightly modified - I used a 100K output pot instead of a 10K pot and I can switch off the diode limiter on the output for more of a booster sound. It's really amazing how many sounds you can get out of the thing with two simple mods.

I took a look at the waveforms on my scope this afternoon. You can get everything from soft clipping to really hard asymmetrical hard clipping. It's a fun circuit. I'll post pictures of it in a day or two. I'm still working on the enclosure graphics and stuff. I'm thinking about using my airbrush to come up with something interesting... 

[jmusser]

I made mine on perf quite awhile ago, and it's still one of my top 10. It's off the schematic that Aron had sorted out from an original I believe. To me, it's a "must build"!

[markm]

I've had this one on my list for quite a while now.....maybe it's time 

[brett]

Hi Paul
I tried 3 diodes and liked it better than 2.  Also, to tame the gain just a bit, I put a 22 ohm resistor on the emitter of the NPN.  It's a great circuit for sure.
cheers

[Paul Marossy]

I tried 3 diodes and liked it better than 2.

You mean two in series and the other one? That would give you a little more asymmetrical clipping...

[Paul Marossy]

I just found out that the schematic I have appears to have an error on it: the 10K output pot is supposed to be a 100K pot. So, that means that mine is built "to spec" except for the diode limiter switch.

Here's Aron's schematic: http://www.diystompboxes.com/pedals/bosstone.gif
And here's the GEO schematic: http://www.geofex.com/FX_images/bosstone.gif

I assume Aron's is correct? Just thought I'd point out that discrepancy...

EDIT: Another thing that I just noticed... the GEO schematic appears to show all of the caps as a polarized type and Aron's schematic doesn't. 

[jmusser]

If you look in Aron's notes, he says that the output pot is 10K, and that's one of the mods. That's how I have mine, and it has huge output with it.

[brett]

Hi
given the low output impedance of the PNP transistor (ie it's an emitter-follower), it would make sense to keep the output pot somewhere down between 1k and 10k.  If I understand RG's comments in his Rangemaster article, low output Z assists grid conduction and overdrive tone in some valve amps.  That might explain some of the magic of Tubescreamers, the Rangemaster and this circuit (so long as it has a small output pot).  Maybe somebody could test it with some different pots?

And yes, the 3 diode idea is for 2 in series and 1 antiparallel with those.  IMO this arrangement gives delicious tone to this circuit, the Distortion+ and other diode clippers.  It also lifts the max output to a ridiculous amount (2V p-p).
cheers

[MartyMart]

I used this diode arrangement in mine too, it's a fantastic circuit with HUGE output !
( thanks for sorting that one out Aron )
MM,

[rbdl]

I breadboarded this but couldn't decide if it was worth boxing or not. I can't remember if I used a 10k or 100k pot, it was very noisy. Might have to give it another chance.

[Paul Marossy]

If you look in Aron's notes, he says that the output pot is 10K, and that's one of the mods. That's how I have mine, and it has huge output with it.

Oh, I missed that note. It's still not clear if the stock output pot is 10K or not. I assume that it is since RG is usually always right.

given the low output impedance of the PNP transistor (ie it's an emitter-follower), it would make sense to keep the output pot somewhere down between 1k and 10k.  If I understand RG's comments in his Rangemaster article, low output Z assists grid conduction and overdrive tone in some valve amps.

I was testing the circuit with headphones into a digital effects unit, so I'm sure that is different than going into a tube amp. Next, I'll try a tube amp. Anyhow, I like it with the 100K output pot - which, IMO, is still a relatively low output impedance (I mean it's not as high as it could be).

I breadboarded this but couldn't decide if it was worth boxing or not. I can't remember if I used a 10k or 100k pot, it was very noisy. Might have to give it another chance.

Mine is actually pretty quiet for using general purpose transistors. It really depends on the transistors that you use. I used a 2N2222 and a PNP transistor simply marked "420" and has a Hfe of about 320.

[AL]

Have you built Aron's Lava Rim yet? It's a combo Fuzz Face/Bosstone. Fantistic little circuit. I added a tone control on the front end of mine (Oskar Bruil/Joe Gagan) and put in a switch to lift the diodes out. Works great for bass.

AL

[Paul Marossy]

Have you built Aron's Lava Rim yet?

No, but I've heard a rockin' soundclip of it. 

[squidsquad]

Love/Hate relationship.  Had a couple of original units....(in the late 60's)...one had the mojo...cleaned up perfectly...sang for days.  The others sounded good...but no clean-up.  The good one was stolen...the others lost...I attempted (twice) to build...but kept getting a low octave creeping in....nothing like the *real* sound.
I may attempt again...but in the meantime...here's a chance to post my OLD clip again...HA! 
From over 30 years ago.....a stock original (not the *magic* one)...but a good sound!

http://www.freewebs.com/squidsquad/pretty%20scream.htm

PS...the same &^%$^ who got my Jordon also got a vintage blackface Super Reverb and a vintage Strat signed inside the pickgaurd by Mary Kay. Years later,  I learned who stole it...but dare not look for him...for when the smoke cleared...I'd be doin hard time in the Gray Bar Hotel.

[Paul Marossy]

I've read that that BossTone is in the same genre as the Tone Bender, except for the diode limiter on the output. With the diodes switched off, you can get some nice overdrive sounds, and even get it to be a booster. It's a pretty versatile circuit, and it's very responsive to picking dynamics. I like this simple little circuit!

I'll post pictures of my airbrushed, recycled enclosure tonight. 

[Paul Marossy]

OK, here are a few pics. The enclosure had some kind of electronics in it, but it was gutted before it was given to me. I designed the PCB. I decided to try airbrushing an enclosure for kicks - this is what I came up with on a whim...

[markm]

Oh my GOD!!
(I won't get in trouble for that right??)
The paint scheme is very cool 
I like it!

[Phorhas]

Looks awsome!

I remember discovering the BossTone my self, a while back. Fell inlove with it on the first note!
I'm a siclion fuzz whore

[aron]

Awesome Job!

[cab42]

I've read that that BossTone is in the same genre as the Tone Bender, except for the diode limiter on the output.  I like this simple little circuit!

My Bosstone is very much comparable to RDV's Tonebender NPN Si, but with the Bosstone having much more output (appr. 2 hours on the volume pot  )

I have build mine into a plastic enclosure, and to my surprise I have no significant noise problems

I like this simple little circuit!

Me too! You really don't need a status LED - you are never in doubt when it's on.

I'm a siclion fuzz whore

Then try RDV's TP NPN Si!


Regards

Carsten