Low Voltage Boosters

[amz-fx]

New article at AMZ - Low Voltage Boosters

http://www.muzique.com/lab/main.htm

Build a 1.5v overdrive...

-Jack

[petemoore]

Well that certainly answered some questions  ! ! !
 I had to slow my reading, to truly enjoy the initial flavor of the article, and, will be back to see that again !!!
 I read on...forming a Jfet question as I proceeded...hah !!! there's the Jfet right there...and another !!! This is Too Cool !!!
 Have Battery Pack...Need Board.

[Dragonfly]

great stuff, as always !

thanks jack !

[Tim Escobedo]

Nice article, Jack. Another one that sounds really good at 3V, possibly down to 1.5V is the 74HCU04 CMOS chip. That one is naturally sweet sounding. I've gotten some to work at 1.5V, though I think they're only spec'd to 3V.

[R.G.]

I think you may want to add a 9V-to-1.5V down-regulator to these. An LM317 should do it, especially the TO-92 version.

In the real world, a guitarist (or the local bass player) will inevitably want to power them from a wall-powered source and plug 9V into them.

Depending on the parts chosen, this may or may not be fatal to parts inside.

For better or worse, guitar effects live in a 9V world, and someone will either try it themselves, or their "friends" will try it for them.

[petemoore]

Or Lithium Powered?
 I've get a 2n5089 powered up on 3.6v lithium...sounds really smooth too. Was easy to tape leads off it with electrical tape.
 I'd imagine it'd run a long time on the 'found' lithium. I think it was a power backup for a calculator or something.
 After including all the resistors, it biased right up EZ with 10k trim.
 Would the use of a 317 Voltage regulator allow decreased battery change frequency needs?
 One could include a 'starve' pot for a regulator for Q1...without misbiasing it too much or add mounted bias knob also...try running the first stage with wider swing into the Jfet at 1.4v-3v. ...for the very adventurous a dual gang 10k could probably be tapered to raise voltage AnD compensate for bias....that's like OT...lol.
 My L/V Booster Board needs the Jfet side populated... :wink:

[petemoore]

I'm really getting great new tones from this build.
 By having the voltage 'right 'there', limited onthe swing, quite a wide rrange of tonnes can easily be dialed in.
 The regulator is making even greater sense to me since building it. The Variable Voltage supply is like a master clipping. Each transistors bias adjusts ... adjustments to how hard each side +/- of the wave is clipped the the first inversion/clipping [Q1], stage, same adjustment can be made for the second stage which inverts it again [...check my reasoning].
 These clipping points are definable to the ear as the pots are set.
 With a voltage regulator, [master clipping adjuster]
 Trims for V+ to Q's 1 and 2, [stage clipping adjusters]
 Gain knob between stages
 Variable Input Voltage  :idea:  Stunning Tones.
 Very Impressive !!! Smooth Amp like Tones...my Amp is Loving It  :cry: .
 Ok..I tried a few things before it...even a buffer...
 The treble rolloff is part of the bargain here Sure sounds nice and is quite easy...up the input voltage for... :lol:

[davebungo]

A good article but I prefer the 9V option if only because I can nick all the spare batteries I need from my Mother-in-law's smoke alarms.

[R.G.]

Yep, like I said - I think a 9V to low voltage regulator is needed for this one.

It's a 9V world...

[lightningfingers]

I've got a disortion powered from 3V, Tim Escobedo's CMOS drive, using the 74HCUO4.

as for this:

A good article but I prefer the 9V option if only because I can nick all the spare batteries I need from my Mother-in-law's smoke alarms.

:lol:  :lol:  :lol:  :lol:  :lol:

I love it

[Tim Escobedo]

The regulator may be a good idea. Or you can use my Tytewadd at 1.5V. At less than 10uA drain, you could put a AA battery in there and never change it again. At least until it leaks.  :wink:

[amz-fx]

My LM317 online calculator (and schematic) can be put to use figuring out proper values for low voltage regulation -  http://www.muzique.com/schem/lm317.htm

LM317 resistors:

1.5v =  R1 at 330 and R2 at 68 ohms

3v = R1 at 240 and R2 at 360 ohms

This will allow external power to be applied to your low voltage booster pedal.

regards, Jack

[Alpha579]

great, jack, that looks incredibly cool! thanx!

[R.G.]

... 'course, I guess you could do the same thing with a resistor running into a diode and an LED to provide about 3V. Two or three silicons forward biased make a pretty nice 1.5 to 2V source. The impedance is pretty low, too if the current through the diodes is more than 10X the circuit current - which is OK for externall powered.

... hmmm... auto polarity protection, too...

[petemoore]

This little circuit opened up a whole new chapter in attack, tone, and sound dynamics I'd been wanting and missing for a long time.
 I pulled off a wonderful sounding Mr. Fantasy for the first time, and SMILED all the way through !!!
 Quite a different horse than I'm used to riding, glad like heck already that it's in the stable...took a minute or two to figure out how to jump on, and kick it...very interesting response to hard and soft picking, great voicing up and down the neck...WOW...
 Thanks to Jack Orman at AMZ !!! Very superb article, quite the usable little monster...
 I'm about to tie the wire over [I have a 120k in series with the 68k I can 'tie past' real easy for 3V operation] and see whappens at 3V.
 I'm increasing the input voltage and controlling it with a DynaComp, and also have a source to ground cap of 10uf ...
 I'm hearing lots of old songs tones I recognize coming out of my amp now.
 It's really very very nice, I'm about to box it up and build More 3V circuit