freestompboxes.org

Hello, this weekend I built a JFET boost based on my modifications to Analogguru's JFET boost schematic. It works great, so I am now presenting it to the community as the first DIY article on my new site!
Check it out:
https://solgrind.wordpress.com/2008/01/21/jfet-boost/
This is a step-by-step tutorial complete with layout and schematic for building on perf board. It also includes instructions on the perf board building technique, so I highly recommend this to anyone who hasn't built on perf before and especially to anyone just starting out.

Enjoy!

You can see the rest of my site here:
https://solgrind.wordpress.com
But there isn't much on up there yet. I hope to add new info and projects to it regularly.

Great site you have so far. Thanks. Your graphics are terrific.

Thanks! So far, I have been very impressed with WordPress' services and features.

Perhaps to complete the WEB site package you could link to a few sound clips?

drmathprog wrote:Perhaps to complete the WEB site package you could link to a few sound clips?

Maybe, but I will need to purchase additional space from WordPress to be able to do so. I don't want to have to link to files off-site.

I will keep the idea of sound clips in mind; I know alot of people are into those.

drmathprog wrote:Perhaps to complete the WEB site package you could link to a few sound clips?

I've never seen such a complete project: everything is there to make your own sound clips Soundclips of a booster will tell you more about the amp than the pedal, though...

modman wrote:Soundclips of a booster will tell you more about the amp than the pedal, though...

Very true! This booster - like every booster I've ever tried - can react very differently with different amps. It depends on how good the amp sounds with it's input being boosted. Some amps, like my big tube amp, sound absolutely beautiful with it; while other amps, like my tiny practice amp, sound like they're about to die.

Great write up. I need to get myself some more FETs, I've used all mine up now! I'll give it a build this weekend I think

Nice one,

One question.
Doesn't it pop? I'd expect a pulldown resistor in the input?

I dunno. I didn't bother to notice. Maybe, but not anything loud.
I guess you could add one if it's an issue. I figured that since the input is shorted to ground while bypassed, it wouldn't need a resistor to bleed it off, but since there is that split second while switching that it's left open, yeah there could be a little pop. When I build pedals for myself, I don't usually care about that stuff because I never hear it while performing. The only time I get picky about little things like that is when I build for others.

Martin what kind of 22uF caps are those? Electro or a tant.
I have a few TRW caps that look just like that. 60's military stuff is what I was told but I can't seem to find any other info.

RLBJR65 wrote:Martin what kind of 22uF caps are those? Electro or a tant.
I have a few TRW caps that look just like that. 60's military stuff is what I was told but I can't seem to find any other info.

Sorry, I missed this question.
The 22uF caps are Sprague 150D tantalums. They are an industrial/military grade part, but you can get them from places like Mouser and Allied no problem. I got a bunch of 'em in a grab bag years ago and they perform wonderfully! If I am not mistaken, they are one of the very few tantalum-type caps that pass mil-spec.

soulsonic wrote:The 22uF caps are Sprague 150D tantalums. They are an industrial/military grade part, but you can get them from places like Mouser and Allied no problem. I got a bunch of 'em in a grab bag years ago and they perform wonderfully! If I am not mistaken, they are one of the very few tantalum-type caps that pass mil-spec.

Here's a another tantalum line that I stumbled across the other day that are mil-spec:-
http://docs-asia.electrocomponents.com/ ... 718480.pdf

Greg_G wrote:Here's a another tantalum line that I stumbled across the other day that are mil-spec:-
http://docs-asia.electrocomponents.com/ ... 718480.pdf

Oh yes, they look like they are they same style as the Sprague. The CSR13 is what you want to look for; that's the type mentioned on both the Sprague and Kemet spec sheets. I wouldn't be surprised if there's some other brands that have it too. I guess it's something all the serious players have to offer if they want to be able to make any military sales.

Anyone here ever mess with wet tantalum types? I see them in catalogs, but they are totally sick expensive, so I haven't had the guts to spend that kind of money on a whim.
http://www.vishay.com/docs/40023/109d.pdf
$25+!!!
http://www.mouser.com/Search/ProductDet ... N5bA%3d%3d