Author Topic: "Buckaroo"-mod: "-De-Floater"  (Read 3605 times)

puretube

"Buckaroo"-mod: "-De-Floater"
« on: July 16, 2007, 12:13:05 PM »
So I had last FX-X entry (Modzky)`s prototype breadboard still lying there,
which actually had come forth from trying to de-crackle a certain (in-)famous boostortion, now abandoned,
when I thought: hey, before tearing it apart, let`s look what`s up with that other (MarkM`s "Buckaroo")  entry,
which could easily be breadboarded out of half of that modulation circuit,
although I don`t like building other people`s circuits...

Ripped out half of the circuit, swapped the BC550 (BJT) for a BF245 (FET) I had on hand,
replaced the fixed collector-resistor with a pot, and hooked up scope and amp again.

Nice ~10 x boost (@ 1M load), after the (crackling) appropriate "bias" (drain voltage) was found.

Wait: what happened when I accidentally touched the grid and another wire:
the sound went away, and didn`t come back.
It did come back slowly however, when I touched the grid again, while also touching the strings
with the other hand...
(it could also be brought back by several times rotating the pot, while it was more difficult now
to find the sweet spot).
hmmm: what`s that? floating volume control?
yes: when touching positive voltage and grid the drain voltage went one way,
when touching grid and ground, it went the other way.
Would stop moving, when letting loose.

What does the schoolbook have to say to this phenomenon? Nothing.
But it was evident, that this grid was sensitive to "static" charges.
Looking further in the book,it seemed that Fig.10 was close enough to try for a cigar:
and: yes, out came "The -DE-FLOATER":



in form of an extra resistor between grid and ground.
No more runaway of the drainvoltage due to environmental influences...
(4M7 can be used for that extra resistor and the pulldown one, to stay on the high input impedance side...).

Thanks for the inspiration!  :icon_smile:

markm

Re: "Buckaroo"-mod: "-De-Floater"
« Reply #1 on: July 16, 2007, 12:29:06 PM »
Holy Smokes!
Very Cool!!  8)
Ya know Puretube, I am honored that you'd even LOOK at one of my measily little circuits let alone use it!
That's a great idea for sure and I'll have to give it a try.
Thanks for sharing and having a look at the Buckaroo.......not that it's anything Real Special, it's pretty darn basic really but, it does sound good dont' you think?!
Again, thanks for the mention and the info, Much Appreciated!

puretube

Re: "Buckaroo"-mod: "-De-Floater"
« Reply #2 on: July 16, 2007, 12:46:14 PM »
Welcome,
I do even read posts ( :icon_wink:):
you mentioned to draw more attention to The GALLERY  :icon_smile:
(http://aronnelson.com/gallery/)

Attention for the FX-X monthly contest
(Contest Archives)
isn`t bad, either...
 :icon_cool:

Dragonfly

Re: "Buckaroo"-mod: "-De-Floater"
« Reply #3 on: July 16, 2007, 12:50:13 PM »
Welcome,
I do even read posts ( :icon_wink:):
you mentioned to draw more attention to The GALLERY  :icon_smile:
(http://aronnelson.com/gallery/)

Attention for the FX-X monthly contest
(Contest Archives)
isn`t bad, either...
 :icon_cool:

CIRCUIT TRAMP !  :D

puretube

Re: "Buckaroo"-mod: "-De-Floater"
« Reply #4 on: July 16, 2007, 04:06:13 PM »
Welcome,
I do even read posts ( :icon_wink:):
you mentioned to draw more attention to The GALLERY  :icon_smile:
(http://aronnelson.com/gallery/)

Attention for the FX-X monthly contest
(Contest Archives)
isn`t bad, either...
 :icon_cool:

CIRCUIT TRAMP !  :D

WHAT you call me?
TRAMP?
OK - I don`t wear continental clothes or stetson hats,
but it makes me feel good to know one thing:
y` know: I`m a LOVER!


 :icon_biggrin:


(inspired by Carla & Otis...)

Ben N

  • Awesome!
  • ****
  • Posts: 4621
  • Total likes: 638
  • Ben N. - really! Now Israel, once Baltimore
Re: "Buckaroo"-mod: "-De-Floater"
« Reply #5 on: July 16, 2007, 04:17:40 PM »
I feel a country song coming on...

puretube

Re: "Buckaroo"-mod: "-De-Floater"
« Reply #6 on: July 16, 2007, 04:25:26 PM »
...ya straight from the Georgia woods.
That`s good!



(still inspired...)

Dragonfly

Re: "Buckaroo"-mod: "-De-Floater"
« Reply #7 on: July 16, 2007, 10:08:16 PM »
Welcome,
I do even read posts ( :icon_wink:):
you mentioned to draw more attention to The GALLERY  :icon_smile:
(http://aronnelson.com/gallery/)

Attention for the FX-X monthly contest
(Contest Archives)
isn`t bad, either...
 :icon_cool:

CIRCUIT TRAMP !  :D

WHAT you call me?
TRAMP?
OK - I don`t wear continental clothes or stetson hats,
but it makes me feel good to know one thing:
y` know: I`m a LOVER!


 :icon_biggrin:


(inspired by Carla & Otis...)


 ;D