MOSFET Boost + Mini-Booster build report

Started by bigjonny, July 07, 2005, 01:31:17 PM

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bigjonny

First off, my sympathies go out to those in London.  I don't really have any great words to say, but do have some family friends who live in St Alban's and commute on the Thameslink, and wish my best to those facing a difficut time.

Anyhow, to the business of the site...

So, I finally decided to build a booster, and I was torn between the AMZ MOSFET Boost and AMZ Mini-Booster, so figured I might as well pop both of them in one box, since I had a nice big 1590BB lying around, and I am pleased.  Included below are shots of the build and my layout.  Anyhow, I know these are both well documented builds, however, I've seen layouts for two MOSFETs in series and two Minis in series, but never a MOSFET into a Mini, so I figured, I best report about it, here.

The layout, I basically lifted from two of Torchy's stripboard layouts, placing one atop the other, and sliding some components around to fit things in nice and tight.  With two circuits in one box, I realize I could've probably saved on some of the power supply components, but it didn't seem to save much room, so I just wired everything "as is" from the schematics.

With two boosters in one box, I figure I have the advantage of 4 different states of boost, and the two stomps switches are close enough that I can stomp them together, if need be, yet far enough apart, it is no hassle to miss one while stomping the other.

I placed the MOSFET Boost ahead of the Mini-Booster, since the MOSFET Boost has such high impedance, and it certainly does make my tone much brighter to have that high impedance buffer in there.  If had a BOSS pedal as a buffer before, and I can say with all assuredness that the MOSFET buffer sounds MUCH better (brighter).  I'm always turning the treble to max on my amp, too, so the extra brightness is much appreciated.

I used Jack's mod for toggling the MOSFET Boost between "boosted gain" and "1:1 gain", so the MOSFET is always on, buffering my signal.  Works good!  The Mini-Booster sounds great, and when I tested it at band practice, definitely found myself stomping on it more often than the MOSFET, however, I can also dial in the double-boost for that over-the-top gain.  Works well -- nice and gritty.  

The use for each boost I ended up settling on was using the MOSFET Boost for a slight boost (like when going from strumming to picking), and the Mini-Booster for those nice sustaining leads.  Both on for those REALLY loud leads.  That Mini-Booster slight crunch is so sweet, but having built a BSIAB II, I guess I already knew that.

BTW, I used J201 for my trannies in the Mini, and BS170 for the MOSFET -- all purchased from Aron, along with my stripboard and stompswitches.  Thanks, Aron!

I am also pleased how I was able to cram all this into a 1590BB.  I was a bit concerned, as I had to be pretty accurate with my drilling, but (at least this time) everything worked out.  Not the neatest job; not the sloppiest.  I sheilded the input wire, since I had saved a bundle of this stuff from being thrown away once.  It's hard to see in the "guts" shot, but I used heat shrink on 2/3rds of the power plug terminals.  I cuts them long so the rubber pushes the batter away from the power terminal.  I also heat shrank the LED leads, too.  Wondeful thing, heat shrink.  So glad I bought that heat gun!

I commented on the finshing in another thread, but here's step-by-step overview:
    Drill, sand and prime metal; clean with mineral spirits
    Brush on paint onto the metal with Oil-based "Golden Delicious" Paint, from
Dixieline
Bake box @ 200 degrees
Buff dried box with fine steel wool
Wipe box clean
Write on box with a Sharpie
Lightly dust the box with Oil-based spray-on polyurethane, until Sharpie ink is sealed
One final, thicker coat of Polyurethane for good measure
Rejoice![/list:u]



gaussmarkov

Sweet, a really versatile boost  pedal.  I have the dual MOSFET booster on my short list of boxes to build.  I'm planning to A/B it with a friend's ZVex super duper.

It's fun trying to get everything to fit, isn't it?  Especially when you are as successful as you were.  :)  I also like your box--cool and functional.  Thanks for posting everything, including the layout.

bigjonny

Glad to!  Hope it helps.  Please do let me know if the layout is big enough.  I can easily make it larger if need be.