HEAVY DARLING

Dragonfly · January 27, 2008, 03:43:29 PM

My entry for this months FX-X contest...

The Heavy Darling is a SIMPLE fuzztone that cleans up great, has old school character, and good sustain...pretty much ANYONE who can solder should be able to build this one. It uses a MPSA13 Darlington transistor in the 1st stage that pushes the 2N3904 into full saturation. The 220k resistor limits the amount of saturation, and you could certainly experiment with values here. A pot could also be used to give some variable gain, and you could even set up the pot in a similar manner to the Orpheum, Fuzzrite, and Shin-Ei style fuzzes.

ENJOY !

SOUND SAMPLE #1... Clean amp first, then the same riff with fuzz on !

CLICK HERE FOR SOUND CLIP #2 ...Full on fuzz, some single note soloing, then with the volume of the guitar rolled back !

mnordbye · January 27, 2008, 03:51:54 PM

That's a great contender, indeed! Just dig the sound of your newest creation, Andrew.

Magnus N

bigjim · January 27, 2008, 03:58:54 PM

Sweat

$uperpuma · January 27, 2008, 04:44:20 PM

I LOVE how this sounds with chords.

earthtonesaudio · January 27, 2008, 05:11:11 PM

I like the tone for chords as well. Nice work.

Dragonfly · January 27, 2008, 05:42:05 PM

Thanks guys. It was something I threw together in about 10 minutes on the breadboard..I love it when that happens ! I'll be developing it further, but I figured I'd post a "basic version" for you guys to build / play with !

Marcos - Munky · January 27, 2008, 10:19:23 PM

Nice, Andy. Another effect on my "to build" list

.

John Lyons · January 27, 2008, 11:35:42 PM

Sounds great andy!
I was just looking at your site and noticed the schematic there, then saw it here with clips...
The site looks nice, just a start I'm sure.

John

Barcode80 · January 28, 2008, 12:59:46 AM

Andy, permission to post a rough pcb layout i just did?

Dragonfly · January 28, 2008, 06:27:19 AM

Quote from: Barcode80 on January 28, 2008, 12:59:46 AM
Andy, permission to post a rough pcb layout i just did?

Sure ... Post away !

Thanks for asking!

GravityRobert · January 28, 2008, 07:34:59 AM

Sounds great, I'd like to make this one

Dragonfly · January 28, 2008, 12:04:08 PM

Quote from: GravityRobert on January 28, 2008, 07:34:59 AM
Sounds great, I'd like to make this one

Its easy to build sounds great, and none of the resistor values are "critical"...so if you don't have the "exact" value, thats ok...build it anyway !

GravityRobert · January 28, 2008, 12:23:01 PM

Do you have a pic of your pcb? I'd like to etch one in my first batch. This fuzz sounds good

PurpleStrat · January 28, 2008, 12:31:30 PM

Everything else aside, you have always made some great Fuzz!

km-r · January 29, 2008, 02:43:31 AM

uh... noob question.

the first tranny is a darlington which should be biased at 1.4 to start conducting. your reading says 3.77V... why is that?
or is the rule "just bias at least 1.4v on the base"

?

earthtonesaudio · January 29, 2008, 08:24:42 PM

Quote from: km-r on January 29, 2008, 02:43:31 AM
uh... noob question.

the first tranny is a darlington which should be biased at 1.4 to start conducting. your reading says 3.77V... why is that?
or is the rule "just bias at least 1.4v on the base"?

I don't really know what rule you're referring to, so this may or may not answer your question.
A silicon transistor will cause a voltage drop of 0.7V from collector to emitter, and a Darlington is basically 2 silicon transistors... (0.7 + 0.7 = 1.4V)
Others feel free to correct me if I'm wrong (I'm still a bit of a noob myself).

But in regards to "rules" in general, stompboxes are a niche of electronics, so many of the rules you read in textbooks don't apply to stompboxes. We're unconventional.

Barcode80 · January 30, 2008, 12:44:00 AM

Bear in mind that though the layout shows one leg of Q2 unconnected, it is actually connected by traces they just somehow didn't end up showing in the graphic.

I guessed at tranny pinout given the usual orientation of PNP silicons because i was just whipping it together, so if it is wrong you may need to do some twisting

GravityRobert · February 11, 2008, 08:34:18 PM

Ca anybody verify this pcb?

Dragonfly · February 11, 2008, 08:48:27 PM

Quote from: GravityRobert on February 11, 2008, 08:34:18 PM
Ca anybody verify this pcb?

It looks like it has errors...

Q1 is 180 degrees from where it needs to be

Q2 has no connection for the collector

I didnt go through the rest

brett · February 11, 2008, 09:22:06 PM

Hi

Quotethe first tranny is a darlington which should be biased at 1.4 to start conducting. your reading says 3.77V... why is that?
or is the rule "just bias at least 1.4v on the base"?

The rule is that a conducting, NPN silicon transistor has a base voltage about 0.7 V DC above the emitter voltage. For Ge the voltage is 0.3 V.

This Darlington consists of two transistors connected emitter-to-base, so the voltage drop is 1.4V (when conducting). I suspect that the 3.77 V refers to base voltage wrt ground. If so, the voltage across the emitter resistor is about 2.37 V.
cheers

PS For more fun, you can also work out the emitter current from V=IR. Once you know Ie, you can calculate the voltage (using V=IR) across the collector resistor because Ic is almost equal (99.8%) of Ie. That lets you calculate the collector voltage, which is handy to know, because for many circuits it should be about half way between the power supply and ground (0 V) (usually 4 or 5 volts).

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HEAVY DARLING