My DIY stompbox

Dr. Zoidberg · 19th March 2008, 12:52 PM

Hello everyone! Recently I have finished work on a very cool distortion pedal and now I'm glad to introduce it.

The scheme is attached below. It is taken from here:
http://forum.gtlab.net/cgi-bin/yabb2...=1180818602/90

The stompbox is built on russian JFETs KP303A or 2P303A, which could be replaced with J201. I think that russian transistors are very good because of their low noise, metal body protecting them from outer electircal interference, and extra durability. Try to get them, guys. And no goddamn fitting by U and Id parameters!

All capacitors except C9 and C10 are film caps.

Nothing difficult I think. Few words about the sound: it is powerful and grinding. It is True and Evil hi-gain overdrive! In my opinion it sounds better than most of overdrive/distortion pedals you may find at musical store.

Photos and sound samples will come soon, I guess not later than next week.

Andronico · 20th March 2008, 10:46 AM

Hi, is your overdrive based on the Brown Sound In A Box I pedal ?

Dr. Zoidberg · 21st March 2008, 07:40 AM

Hello, Andronico. I guess it is a kind of modification of the device you've mentioned. Here's the story of mods (in russian unfortunately):
http://gtlab.net/gtlab2/readarticle.php?article_id=33

I can't say more, sorry. I just took scheme, necessary parts and combined them in a small box.

Andronico · 21st March 2008, 11:59 AM

Thank you Dr, I visit your page (using google to translate from russian to english) and understood some of the modifications.
I made a BSIAB II two years ago and love how it sounds. How is yours compared with BSIAB II ? Is the same type of sound ?

Dr. Zoidberg · 21st March 2008, 02:06 PM

Actually, I'm not the author of all those mods, heh!

The answer is "Yes!", it sounds similar to BSIAB 2, but more angry or something like that. Anyway the difference is not too big. May be there is a rational point in comparing the sound by samples? I mean that this Sunday I'm gonna record how it sounds and place it here. I'll use microphone, tube amplifier etc. Don't you want to join the experiment?

P.S.: Main advantage of the scheme I attached above is that you don't have to fit transistors by cut-off voltage and drain current. I don't think it influenced the sound much.

scotty1978 · 9th December 2010, 01:32 PM

Anybody know where I could buy KP303A or 2P303A to ship to the United States?

firechief · 17th December 2010, 02:59 PM

DrZoidburg What is the value of C6? Surley it cant be 2200 Ufd ! Also what fets are used?

Nigel Goodwin · 17th December 2010, 08:17 PM

Quote:

Originally Posted by firechief

DrZoidburg What is the value of C6? Surley it cant be 2200 Ufd ! Also what fets are used?

It's clearly marked as 2200(pF) - the FET's are labelled as well, some strange Russian numbers presumably

try substituting some you can get.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Stompbox problem	lukeareid	Instruments and Amps	0	16th December 2008 02:56 PM
help in changing cap values for a disto stompbox	pinkanarchy	Parts	3	22nd June 2008 03:26 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

20th March 2008, 10:46 AM	#2
Andronico diyAudio Member Join Date: Jun 2004 Location: Santos Lugares	Hi, is your overdrive based on the Brown Sound In A Box I pedal ?

21st March 2008, 07:40 AM	#3
Dr. Zoidberg diyAudio Member Join Date: Mar 2008	Hello, Andronico. I guess it is a kind of modification of the device you've mentioned. Here's the story of mods (in russian unfortunately): http://gtlab.net/gtlab2/readarticle.php?article_id=33 I can't say more, sorry. I just took scheme, necessary parts and combined them in a small box.

21st March 2008, 11:59 AM	#4
Andronico diyAudio Member Join Date: Jun 2004 Location: Santos Lugares	Thank you Dr, I visit your page (using google to translate from russian to english) and understood some of the modifications. I made a BSIAB II two years ago and love how it sounds. How is yours compared with BSIAB II ? Is the same type of sound ?

21st March 2008, 02:06 PM	#5
Dr. Zoidberg diyAudio Member Join Date: Mar 2008	Actually, I'm not the author of all those mods, heh! The answer is "Yes!", it sounds similar to BSIAB 2, but more angry or something like that. Anyway the difference is not too big. May be there is a rational point in comparing the sound by samples? I mean that this Sunday I'm gonna record how it sounds and place it here. I'll use microphone, tube amplifier etc. Don't you want to join the experiment? P.S.: Main advantage of the scheme I attached above is that you don't have to fit transistors by cut-off voltage and drain current. I don't think it influenced the sound much.

9th December 2010, 01:32 PM	#6
scotty1978 diyAudio Member Join Date: May 2008	Anybody know where I could buy KP303A or 2P303A to ship to the United States?

17th December 2010, 02:59 PM	#7
firechief diyAudio Member Join Date: Sep 2008 Location: Near Seattle Wa	DrZoidburg What is the value of C6? Surley it cant be 2200 Ufd ! Also what fets are used?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)