Let's talk about the Jordan Bosstone: Part II

[Plexi]

I reborn this old thread:
http://www.diystompboxes.com/smfforum/index.php?topic=78321.0
A lot of pics are down, and would be great to continue talking about this.



I was tweaking some schemes and testing some transistors and diodes in the sockets.
A good advise is to use diodes instead of 1n4148 for less compression and fuzz, more volume and bass.

Am I wrong, or this fuzz as is, without any change, sounds in someway like it have a crooked wah before?

[thermionix]

A good advise is to use diodes instead of 1n4148 for less compression and fuzz, more volume and bass.

Do you mean use LEDs?

[cab42]

The Bosstone was one of my first builds. I think I was Inspired by this thread:

http://www.diystompboxes.com/smfforum/index.php?topic=30813.

[Plexi]

A good advise is to use diodes instead of 1n4148 for less compression and fuzz, more volume and bass.

Do you mean use LEDs?

You're right... my bad.

I tried with a few transistors today, and found that it still sound without anything in Q2.
You'll get a nice low fuzz.
With the lowest hfe at Q2, it'll cleanest more, no oscillations.

The Bosstone was one of my first builds. I think I was Inspired by this thread:

http://www.diystompboxes.com/smfforum/index.php?topic=30813.

Great thread, thanks!
I'll try .1uf

My next step is to see what's the deal with Rocket WTF fuzz

[Kennt82]

I made a layout of the KMA Fuzzly Bear. It's  based on the  Bosstone with  much larger input cap,  4 clipping diodes for more headroom, and even a  voltage starve.  Try those 1st 2 changes if you're bread boarding one.  It sounds so good I also want to try the Rocket WTF as it has some similar mods.

http://i.imgur.com/3XrsbPL.jpg

[Plexi]

Great!
I'll try on protoboard some of your mods.

Now I'll leave a Germanium PNP at Q2: 2SB54.
A lot of fuzz, cleans great, and no oscillations at all.

I see that you used a big hfe at Q1; I have some BC109C (~600 hfe) and made the oscillation think worst.
Any of those troubles? Voodoo Lab uses MPS18 there 
Tried MPSA13 (I know: a beast darlington), and get a rare synth/octave sound..not bad.

How about the 500k gain pot? better results?
I'll add 5k/10k resistor in between lug 1 and ground.

[Kennt82]

Good idea on a resistor between Gain #1 and ground, otherwise it cuts the signal. I put a 1k on mine, but kept it like the original for that layout.

[duck_arse]

when I was doing bosstone on the BB, and feeding in sig gen clean signal, I could get it to oscillate - always at "a" frequency - quite easily by reducing the input level quickly. all different hFE transistors, both spots, nearly always would oscillate. but with a guitar input - never. I thought that odd. doesn't oscillate that I can hear now it's built, either.

[Plexi]

Today I've trying a few more transistors on Q2.
The difference is really notorious.
What I can resume:
- 2N3906: NASTY... huge mid/lows boost when you clean (croocked wah).
- 2SB54: sweet, the best one.
- Nothing: good od/fuzz.

I would like to have the 3 options: dpdt ON-OFF-ON, and switch between Emiters?

[suryabeep]

I would like to have the 3 options: dpdt ON-OFF-ON, and switch between Emiters?

I think you can get 3pdt toggles from Tayda at a reasonable price...I did a similar transistor switching mod on a meathead build

[sominka]

Hey Plexi

Why are you trying to squeeze one out in your avatar?

[Plexi]

I would like to have the 3 options: dpdt ON-OFF-ON, and switch between Emiters?

I think you can get 3pdt toggles from Tayda at a reasonable price...I did a similar transistor switching mod on a meathead build

Sure.. !
The main idea was to try to "set" bias on Q2... that's the difference in between: the hfe are 'as is'.
I see that they're almost free in the schematic, only 18k resistor from 9v...to Q2 and then to all the rest: I could tweak that resistor, but will mess the overall voltage.
And remembering that res is feeding Q2's emitter.

Maybe playing with some value from Collector to ground?
Leaving the 3906's high hfe, and place there (1k?) to tame a bit that response (like Ge transistor).

Just an idea..I'll take a chance later on protoboard.

[sergiomr706]

I have 180hfe on the npn and 150 hfe pnp and the in capacitor on a rotatory 6 position, from 22 to max 470nf and its one of my fave fuzzes, reading some more im about to try 1n cap there too. I tried to mimic that never gonna give you up almost trombone fuzz sound from the black keys cover. Really close on the biggie cap.