Bazz Fuss cutting off?

[ProductNumber01]

So I made my very own Bazz Fuss according to this:



It works great and all, but when I play higher notes on higher strings on my guitar, the sound dies out soon after the note is played.. I can't get more than a second's worth of sustain on any of the notes on my G, B, and E strings..
When I put my pickup switch to the middle (Gibson SG) the note is sustained just a hair longer than when I have either of the pickups being used.. Could anyone help me out? Any input is appreciated greatly.

[RandomGlitch]

It's the collector resistor value.

What I have found is that with 2N3904s and 2N2222 transistors is, having a 10k in there makes it behave like this, quite gated and you have to play high strings very hard to get a sound.

Try some higher values - 100k works for better decay with those transistors.

If you use a MPSA13 darlington transistor 10k works OK.  

For bass, I quite like the gated effect. So much so that I put it on a pot. For guitar I can see you'd probably want more sustain.

I found that the 2N2222 is more "gatey" than the 2N3904.

How "hot" your pickups are definitely has an effect on all this, as your own experience shows.

Hope this helps.

[LucifersTrip]

I was ready to hit "post" when RandomGlitch posted....+1 to that and here are details, anyway

should hit this first:



...but in this case, it's just a standard misbiasing because you used the wrong transistor or wrong resistor.



use 100K with a "normal"  bipolar junction transistor

use 10K with a darlington transistor

[midwayfair]

Raising the biasing resistor in my experience will not completely solve the spitty decay issue when using a lower gain transistor. I was still getting some gating going all the way up to 1M! A diode with a higher Fv was a much faster fix. I found something around .65v was better with an MPSA18; you might need to use a couple BATs in series or a MOSFET to get a good decay with a 2N3904. Of course, the spitty nature of the circuit when using those lower gain transistors is one reason to use the lower gain transistors in the first place, and a different diode is going to change what kind of "magic" happens. You might do better to pick up the darlingtons if you want it to be smoother.

[nascarbean_97]

You could also swap it out with a 2n5088. worked for me on the sustain at least.

[LucifersTrip]

an easy fix using what you have

[Toney]

 Yep just use an MPSA13 = crisis over

[CoolJohnny]

iv'e built dozens of varients of this thing over the years (actually working on one right now) and i can say without equivocation that you definitely need to be precise about that biasing. use a pot when you breadboard and measure it when you find the sweet spot. THAT is your resistor value, not what is on the schematic. secondly, a darlington is a must! fun thing is trying different combinations of transistors for different effects. i have had success with Si/Ge hybrid darlingtons in the past, but again, biasing is a bitch...most cases i leave a pot there instead of using a fixed resistor. right now i'm trying to figure out the best possible way to buffer this thing so i get better high-end and stability out of a Ge version.

[Canucker]

darlington transistor or forget about it for guitar is my feeling...and lower the output cap from 4.7 to 2.2 or close... Find something better and I'd love to hear about it.