Page 1 of 2

Gaspedals - carb

Posted: 09 Oct 2007, 15:39
by polarbearfx
feels and seems like a rangemaster??? what do you say???

http://www.gaspedals.net/carburetor.html

(admin: added link. please at least post a link for people who never heard about this pedal)[/color]

Posted: 09 Oct 2007, 16:27
by bacaruda
I bought one of the "indroductory" models (like $150?) when they first came out. I wasn't into pedal building too much at the time so I didn't try removing the goop (which seemed really solid).

Plus, I had no desire to reverse engineer it, because it sounded like CRAP with every single guitar/amp combo I tried. I even tried it through a friend's vintage AC-30 (where the carb is supposed to sound its best). Just dull, lifeless, and aritificial-sounding. I kept it for a few months, and took it out every so often to see if my ears had changed. Nope, still CRAP.

I'm not very much help here, but one thing I do remember is that the gain knob crackled like an RM/SHO/COT.

EDIT: Didn't Clay Jones trace this? I thought the Carb was included in his Christmas day rant on TGP last year.

Posted: 09 Nov 2007, 04:42
by Mykkus
Bonamassa has one on his board at the moment.

seems very similar to many pedals...

Posted: 18 Nov 2007, 08:26
by burningwater
Edit: out of respect for builders in general I am deleting any posts which discussed circuits.

Re: Gaspedals - carb

Posted: 02 Sep 2010, 20:52
by plesur
This is my first degoop.
Gaspedals Carb Top 1.jpg
Gaspedals Carb Top 2.jpg
Gaspedals Carb Top 3.jpg
Gaspedals Carb Bottom 1.jpg
Gaspedals Carb Bottom 2.jpg
Gaspedals Carb Board Top Gooped.jpg
Gaspedals Carb Board Bottom Gooped.jpg
Gaspedals Carb Board Top Degooped 1.jpg
Gaspedals Carb Board Top Degooped 2.jpg
Gaspedals Carb Board Bottom Degooped.jpg
Gaspedals Carb Pots.jpg
Gaspedals Carb Germanium Diode.jpg
Gaspedals Carb Transistor.jpg
As far as I can tell the components are (from left to right) for the Top Degooped 1 picture
  • ? 16V electrolytic capacitor (I stripped the casing when degooping and can't read the value)
    3k3 1% metal film resistor
    2N5089 transistor
    8k2 1% metal film resistor (for LED supply)
    3k3 1% metal film resistor
    2M2 1% metal film resistor
    1M 1% metal film resistor
    47n 50V Tracon capacitor
    0.1µ 50V Tracon capacitor
    1N4148 diode
    1N4148 diode
    Unknown germanium diode, forward voltage 0.235V
Pots are 50K linear for volume and 1K linear for gain.

Switch changes between the germanium and 1N4148 diodes.

Re: Gaspedals - carb

Posted: 02 Sep 2010, 22:33
by Steven_M
Is it an Electra Distortion variant?

Re: Gaspedals - carb

Posted: 03 Sep 2010, 00:08
by culturejam
Steven_M wrote:Is it an Electra Distortion variant?
The parts value lists would seem to suggest that it is likely similar.

I can tell for sure without more of the goop removed.

Re: Gaspedals - carb

Posted: 03 Sep 2010, 00:26
by Greg
Pretty messy build there..

I'd say it's an Electra/COT derivative with non symmetrical clipping = 1n4148 vs Germanium + 1n4148.

Re: Gaspedals - carb

Posted: 03 Sep 2010, 00:37
by freq67
225 for that?...................He must of went to school at RU High.

Re: Gaspedals - carb

Posted: 03 Sep 2010, 01:00
by Greg
freq67 wrote:225 for that?...................He must of went to school at RU High.
Sparkly finish on pretty pictures.. and a little hype, and you have a ready made market at TGP.
Add some goop for mystery and you can't go wrong.

Re: Gaspedals - carb

Posted: 03 Sep 2010, 08:27
by aquataur
The goop was not put there to enshroud the crafty innards, but to disguise the amateur PCB :P
Selling such a device is a shame. Not that those units are particularly cheap.

-helmut

Re: Gaspedals - carb

Posted: 03 Sep 2010, 09:04
by plesur
This is what I have so far for the schematic, I don't have the value for the stripped capacitor yet.

Anyone got any idea what type of diode the germanium is?
Gaspedals Carb Schematic.pdf
(20.53 KiB) Downloaded 260 times

Re: Gaspedals - carb

Posted: 03 Sep 2010, 09:37
by Greg
plesur wrote:This is what I have so far for the schematic, I don't have the value for the stripped capacitor yet.

Anyone got any idea what type of diode the germanium is?
The attachment Gaspedals Carb Schematic.pdf is no longer available
I doubt the exact Germanium is important, as long as the Vf is close.

Have a look at this.. it's almost exactly a COT50 with a volume pot added at the end:

Re: Gaspedals - carb

Posted: 03 Sep 2010, 10:19
by plesur
Greg_G wrote:Have a look at this.. it's almost exactly a COT50 with a volume pot added at the end:
Yes, I noticed that :wink:

Re: Gaspedals - carb

Posted: 04 Sep 2010, 11:15
by aquataur
Folks,

in a sleepless night you think about this and that and it dawned on me:

What is depicted is not a professional pedal at all. Either the buyer fell for a bootleg or we all fell for an april joke.
The case is a standard aluminium case for prototypes, the wiring is done well.
To tell from the gutshots, if a DIY´er made such a pedal, :applause: , nicely done.

But to sell a circuit on a protoboard on a professional basis, is sheer cheekiness IMHO.

I believe that if this really stems from the abovementioned company, they emerged from a garage company run by a single guy.

have fun,

-helmut

Re: Gaspedals - carb

Posted: 04 Sep 2010, 19:36
by modman
Nice work! As is our custom, Plesur is promoted to Degoop Doctor for freely wrecking a stompbox just to draw up a schematic for mankind... :mrgreen:
This entails little less than eternal fame on freestompboxes.org. :wink:

Re: Gaspedals - carb

Posted: 05 Sep 2010, 03:14
by atreidesheir
Brilliant posts Plesur.
I look forward to your input here. [smilie=a_goodjob.gif]

Gaspedals Carb

Posted: 16 Nov 2010, 14:32
by masco
Any schems or layouts for this one?

Re: Gaspedals Carb

Posted: 16 Nov 2010, 15:04
by mcaviel
the search option is great you should try it.
viewtopic.php?f=7&t=737&p=113160&hilit= ... ls#p113160

Re: Gaspedals Carb

Posted: 17 Nov 2010, 15:10
by masco
mcaviel wrote:the search option is great you should try it.
viewtopic.php?f=7&t=737&p=113160&hilit= ... ls#p113160
Not so great. Searched "gaspedal" came up w/ nada.

Great site. Give a newbee a break...