Boss T-Bone Distortio/Octave/Trumpeter

[Mark Hammer]

As an aside, I was surprised to read in an interview recently that Metheny actually started out learning and playing trumpet, before switchng over to guitar.  That explains an awful lot.

[radio]

Ah  ,I  didn't  know  that!

I  of course didn't get his phrasing , needs probably more than

a simple circuit , like ... hours of practice.

[Nick C.]

I've been playing around with the BossTBone on my breadboard. Tweaked it to hell and back. It turns out I need a lot bigger pot for a sag control, a 500k. Maybe because I'm using a wall wort.

Anyway, I'm getting awesome trumpet tones from a dual humbucker guitar, ok tones from my strat and poor from my homebrew dual p90 guitar.

I imagine this maybe another impedance thing, pickup loading problem. Tried a pedal with a buffer in front, and a booster in front without good results. A meg resistor to ground at the input may have helped a little.

Anyone know how to make this circuit respond better to all guitars?

Nick

[pinkjimiphoton]

i think you'll have to adjust the sag control for each kind of input.

maybe find good spots on the pot for each guitar, measure the resistance and add a "preset" resistor at the proper values on a 3pdt switch?

[Nick C.]

Jimi, Definitely, my different guitars are requiring tweaking of the voltage sag, but it goes deeper.

My Guild M-80 sounds so sweet and brassy.

The Strat is much more splatty and harsher with more limitations to what string and fret position will yield a brassy note.

So I figure the differences are:

Higher output pickups, higher Z.

Different harmonic content from humbucks.

500k pots vs 250k

I'm thinking that the single coils are getting loaded much more, so the solution might be related to that. My goal is to be able to dial in a good brassy tone without having to switch guitars.

[pinkjimiphoton]

hi nick, then how about this approach?
change the impedance of the input?

like... get a 3pdt on/on/on switch, and use different input caps/ground references in for each kind of pickup?

i bet there's a sweet spot where you can find that you could wire up where you could effectively be able to just plug whatever guitar in without dicking around with the knobs...

i don't know enough to be able to help, other than breadbox and 10,000 monkeys approach, but i bet RG could sort it out!

[mrmeister]

Hi guys!
Built my T-Bone Version a few days ago. I seems to work but one thing worries me:
When the SAG control ist to 0 i get no sound. Then i dial in some sound and first a get some gated noise and later the fuzz appears. Increasing SAG the sound clears up a little and i get octaves...
I meassured 9.2 V with no SAG and no Sound. The Sound appears at about 4.8 V.

I had to combine resistors to get to the values but i'm within 1% tolerance. I checked my board but couldn't find any errors...

Maybe i've already made an error with my shematic!? i added some DC fitlering and a "Stupidly Wonderful Tone Control". The LED has some pop-filtering.

Someone an advice!?

P.S. The 560pF Cap is 56pF

[pinkjimiphoton]

i think it really depends on the transistors and their gains, you may have "mellowed it out" too much with the tone control?

[mrmeister]

I bought a Buch of 3904 and 3906 and they are all quite high gain. They are about 250 hfe. (But i don't really trust my Meter. For most of them i meassured 300 and more.) The tone controll works quite  softly, when i get fuzz so i don't think This is the reason. But without a sag-controll and with 9V iwould not get a sound. Do you think This could be because of The higher Gain transistors?

[pinkjimiphoton]

temporarily lift the node at r7 and c4, and try the output from the grounded side of c4 (unground it and use as a new output.

i think it's the tone control. and as i recall, very specific ranges of caps worked to get the tone.. often caps aren't even close to what they're marked.

all the higher gain transistors would do would be make it more brassy and edgy, more distortion and louder. can ya post a clip of what you're getting?
also, post voltages etc from each transistor.

hollah back bro

[Nick C.]

I'm using some very generic transistors, so I don't think that's the problem. This circuit is pretty touchy and sensitive to pickups and tone settings.

For trumpet use between 2 pups and tone all the way down, input cap of .1-.22uf, sensitivity 100% (even your 100R might be too much), and I need at least 250k for sag. I tried the same tone control, but didn't like it , so I added a .01uf bypass cap with a pot around the vol pot.

For straight fuzz, big caps at input or out can do strange things as can lifting the diodes. I also removed C2, C3 and reduced C4 to 220pf.

Your schematic looks ok, might just be a bad sag pot.

[Mark Hammer]

Somebody on another forum posted a Youtube link to a recent pedal from J Rockett, and I thought "Hey, wait a sec!  I know that sound!".

[Arcane Analog]

Sounds like Paul Trombetta's pedals as well.

Edit:

[Snufkinoob]

Bump!

I've been wanting to build one of these for some time, and now I'm starting to become more proficient at circuit building I might give it a try in the near future, but just wanted to double check a few things before doing so as I'm not up to speed on my knowledge of circuits.


I'm going by this layout, which I assume works fine and is error free?





I want to get as much brassy, greasy bosstone fuzz sounds out of it, and after reading through this thread, have come to the following alternate component values that seem to get those results going by what people are saying:

R1: 560k
R3: 560k
R4: 470r
R5: 15k
R6: 15k

Q1: 2n3565
Q2: 2n4125


Not sure on the following general bits:

C5: 0.68uF, 0.09uF, 1uF, or 10uF - more texture in the fuzz the higher the value?

Q1 should perhaps have a higher Hfe than Q2?

Use a 250k or 500k instead of 100k on the Bender pot for wider range in sweet spots for brassy tones?

Is the gain toggle switch worth it? Does it change the character of the fuzz tone much, and if I was to omit it, or have it set in one position or the other, what would I need to do/rearrange on the board?

I'd just be using a 9v battery snap, so would that connect +, to Bender 3 and -, to h1 ground (and/or daisy-chained with Attack 1, Volume 1?)

Any help much appreciated. 

[Snufkinoob]

Bump

[Snufkinoob]

So I've tried building it, and it's not working 

Have gone through a few stages of troubleshooting to no avail, and the results are always the same.

When the effect is engaged, there's not much happening. Just a slightly muffled clean tone. The volume pot is responsive, and turning the other pots has an effect on the background noise.

I made a typo above, with C5, putting 0.68uF instead of 0.068uf but I ordered the 1uf and 10uf caps too, and using them instead does nothing. I've tried all the alternate transistors too, with no results. The only thing different to the diagram is that I'm not using the gain switch, but can't see how that would create the results I'm getting.

Any ideas on what I'm doing wrong? I heat-sink everything so hopefully haven't fried anything, but other than a faulty component I can't think what the root of the problem is.

[allesz]

Hallo Snufkinoob, sorry about your troubles, you can post some pictures if you want some help debugging.
You can also build an audio probe and follow the audio trace of the effect to find out where is the problem.

If you want to start from scratch again I would suggest to don't waste components committing the effect directly on vero or perf. Get a breadboard, make the circuit work there, and then solder the same components on the vero/perf/pcb.

Are you also on tdrpi?

[thehallofshields]

It's too bad so many people have fallen short of getting the sounds from jimiphoton's demo. The commercial builds sound great, I wonder how they've gotten the sound consistent from unit to unit.

Can anyone give an explanation of why this circuit sounds the way it does?

I've ended up frustrated the few times I've tried to mis-bias silicon fuzzes. Somehow this NPN-PNP config motorboats mids and I just don't understand it. It does do the Brassy 'Trumpet' thing with the Clipping Diodes Lifted, doesn't it?

[Aryuserius]

Cheers all.  Came across this thread searching for a Sax sound.  Just ordered parts for the build but I'm putting into a hollowed out Wah Pedal.  The idea is to be able to maneuver some of the knobs with your foot ala Wah and have it be more of an expression pedal adding in the dist and "trumpet" effect to articulate. 

There goes my post virginity.

YL

[deadastronaut]

^ cool, now lay back and have a  cigarette...

welcome btw.