Clean Boost

[Kipper4]

I'm looking for a simple beginners clean boost project.
I found this and was wondering if anyone has built it?
http://www.muzique.com/schem/muff3.gif


I also found this that has a good reputation from what i've read but it looks a little more demanding and that scares me a bit.
Anyone done this one?

http://www.muzique.com/schem/mosfet.htm

i know nothing about the Bs170 and the though of zener diodes is scary too.
I'm gonna go google the BS170
that didnt help i've only just got a handle on npn and pnp bipolar transistors.
I know nothing about mosfet . time to do some resaerch. I'm rambling now.
Anyway which do you think i should do?

[Gus]

Have you looked at the beginner project here?

[Mark Hammer]

The MosFet booster is a decent unit.  Very similar in many ways to the ZVex SHO, though still slightly different.  Very good for preserving top end, due to the high input impedance.

The BS170 is slightly static sensitive, so I wouldn't walk around a shag rug in phentex/nylon slippers and a bulky wool sweater, dragging your feet and holding a BS170.  BUt apart from that, you should be safe. 

The zener is easy to get a hold of.  NOte that your choices for zener are more varied than might appear at first glance.  9.1V zeners will come in various wattage ratings, and virtually any of them will be fine.  I mention this because if you ask for one at your local distributor or on an on-line site, there may be others of a different number that will sub perfectly well. In the world of resistors, 1/8w, 1/4w, 1/2w, 1w, 2w, 5w, etc., all have the same number.  They are this or that many ohms.  When it comes to zeners, a zener of a higher or lower wattage will have a different part number.  Just enter "9.1V zener" into Google and you'll see what I mean.

The bottom line is to keep a list of relevant zener part numbers when trying to get one, just so you don't overlook a suitable unit.

The circuit will work just fine with ANY pot taper for the gain pot, but you'll probably be most satisfied with a "C" or "reverse-log" taper, since it will spread out the usable gain changes more evenly rather than squish them into the last 25 degrees of rotation.

[davent]

As mentioned by Mark, both the AMZ Mosfet Booster and the SHO are cool simple circuits. The AMZ, to my ear lends more body to the boosted signal while the SHO gives you some sparkle, each offers a different flavour to my various amp/guitar combos.

Simple and low parts counts so perfect to quickly breadboard up and audition with your specific toys. Both are good for hitting the first stage of your tube amp with a strong clean signal and getting it to break up.

dave

[chi_boy]

Would this be your first build, or do you have a few under your belt already?

[Kipper4]

This would be my second build the first was a kit deacy amp.
This would be the first from scratch from a schematic.
The reason zeners frighten me is because theyre supposidly heat sensative too. and i still might be a little heavy handed with the iron.
I'm gonna be using it with a fender pro jnr.
I'll go on ebay and see how little i can get the zeners and mosfet for thanks for the help guys and i'll  take a look at the beginners projects too thanks for the tip
Rich

[petey twofinger]

built both , the beginner and the amz . still use both , depending . i believe the amz has more boost .

good move getting that proper diode . i used a layout with a different diode listed and after a month the mosfet failed . replaced the diode and the active and everything has been fine . i have a few stereo amz units built into some mini amps . in pedal type designs i have used the beginer npn boost , but . they are both so small i can bread board em pretty quick .

[Kipper4]

i've ordered the mosfets (5) and some zener diodes too
gonna try both booseters i think

[bluebunny]

+1 on the AMZ Mosfet booster, particularly if you're after "clean".  My tame guitarist loves the one I built and won't give it back.  SHO is certainly dirtier, but fun too.

Get yourself a set of heatsink tweezers if you're concerned about frying your diodes (and transistors) when you solder.  A mini croc clip will do.  Mark is quite right to warn about skating across a nylon carpet with the BS170, but otherwise I've found them to be quite robust.  Just leave them inside their anti-static packaging until you need them, and earth yourself before you work (on a radiator, f'rinstance).

[Kipper4]

i bought these Zener diodes will they be ok?

http://www.ebay.co.uk/itm/280864429216?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

[davent]

Those will be fine.

[Kipper4]

thank you kindly sir