Comments on: Davisson’s JFET Vulcan

By: Octavio

Octavio — Tue, 29 Nov 2011 17:32:57 +0000

Hola Gauss. Hace rato vengo siguiendo todos tus proyectos, y ya he hecho algunos. Me gustan muchos los diseños de PCBs, están muy bien ordenados y prolijos.
Te cuento que recientemente armé este pedal… Recién lo acabo de probar, y suena demasiado, tiene muchísima ganancia, yo diría que suena como Heavy Metal… cosa que no me gustó mucho. Yo había oído los clips mp3 de ejemplo y me había encantado como sonaba eso, pero esto nada que ver.

Es una buena distorsión, pero es demasiado pesada (muy Heavy).

Voy a ver de qué manera puedo modificar valores de componentes para aproximar el sonido a esto:
http://diystompboxes.com/pedals/sounds/JFETVulcan5-7-08.mp3

By: sgRED

sgRED — Sun, 13 Mar 2011 13:20:50 +0000

Can anyone tell me, can I try to build it on a VeroBoard?! Would it be right, considering the noise and the shape of the leads on Gauss’s PCB which is great!? Here in Bosnia, it is hard to build pedals because it is hard to order chassis and much of the other stuff that is needed for the build. I have J201′s, but everything else is a bit harder to find…. Thanx anyone for an answer!

By: Leo

Leo — Wed, 07 Apr 2010 19:35:35 +0000

Hi Gauss.
The circuit is excellent, the same the pcb, but has no tone control…What tone stack recommend?
Thanx

By: Flyingz

Flyingz — Fri, 06 Feb 2009 03:06:17 +0000

I rebiased, added BMP tone, removed R17, and changed R16 to 100K
It has some fun in it but nothing special

By: drushton2002

drushton2002 — Sat, 08 Nov 2008 23:28:13 +0000

hey man i can’t wait to try this. are there any tweaks or switches to anything like that? different caps for boosts tone changes etc. i love switches LOL. cool site man thanks for having this stuff

By: culturejam

culturejam — Fri, 31 Oct 2008 18:33:37 +0000

Jim: I built the Vulcan from the PCB layout here, and it sounds much heavier than the sound clip that you posted on your blog. Mine is in Big Muff territory, but not as compressed.

I went with 100k resistors, but then I swapped out JFETs till I got some that would bias properly.

By: Jim

Jim — Thu, 09 Oct 2008 23:00:34 +0000

That’s so weird that it automatically posted a weird link to my blog that I just did about this circuit…
Anyways; go here if you wanna check it out.
http://bandslink.com/wordpress/?p=33

Love your site man!

By: Jim’s Personal Blog » Blog Archive » JFET Vulcan

Jim’s Personal Blog » Blog Archive » JFET Vulcan — Thu, 09 Oct 2008 22:58:20 +0000

[...] I did a breadboard of the ‘JFET Vulcan‘ after reading about it on the Gaussmarkov site. Here lately I’ve been just whipping [...]

By: culturejam

culturejam — Tue, 23 Sep 2008 05:03:49 +0000

Verified!

It sounds awesome. I forgot to check the 100k resistor values and just soldered everything. The result was good, but a little mis-biased sounding. So then I swapped out JFETs, and the closest I could get to “proper” bias is 4.7v, 4.2v, and 3.9v, respectively. Oh man, it sounds so damn good. Like a hot-rodded Muff crossed with a SLO.

Great layout. Thanks!

By: gaussmarkov

gaussmarkov — Wed, 27 Aug 2008 15:35:53 +0000

nice!