Keeley Blacktop - Vintage Silicon Muscle Fuzz


Keeley Electronics

Fairchild’s Audacious 2N3565 – Vintage American Muscle

I’ve fallen in love with the vintage Fairchild Semiconductor’s 2N3565 transistor. Some call it a black glob transistor, a black dot, black top.  Whatever it’s called, it’s a piece of black epoxy that covers the top of the transistor.  I call it sexy.  The transistor has gold legs, a vintage grey body, and a sexy gloss black top.  I’ve got 1000 of them.  I have to make a Foxx Tone Machine Fuzz one day too. So, we have enough for a good couple hundred of the new Blacktop Fuzz.

They’ve Got Silicon Transistors Down in Texas! (and the Texas Motor Speedway!)

In comes the fast and furious world of the 1960s.  The silicon transistor consists of sand and a few fine wires.  Pioneered at Fairchild by Robert Noyce he said it would lead to cheap electronics.  NOICE! …NICE INDEED!  He also produced the first commercially available op-amp.  Ain’t no TS-9s without them Dr. Robert…NOOICE!!!  (Yeah I know Texas Instruments did it first in 1954, but I’ve always liked Fairchild trannies for audio mo’ betta.  It’s like Chevy and Ford.)

Again, what I really like about this transistor is the way it sounds of course.  I like the way Muscle Cars sound too.  I like the way things sound.  This little guy though…puts a smile on my face!  It’s an audio transistor that distorts very well, has just the right gain and is sensitive.  It speaks to me.  Sometimes germanium just doesn’t have enough push and modern silicon can have way too much gain.  These make the perfect fuzz sounds I think.  You know I could go on and on about sound right?  The sound a 0.800 huge lift cam makes, the sound ram horn exhaust manifolds make on a Corvette, the sound of of some Mickey Thomson’s on the Blacktop….

Back to muscle.  Back to the 1960s.  Why didn’t they keep making these glorious sounding transistors for us?  Well, Seymour Cray of supercomputer fame was pushing Fairchild for faster, not fuzzier. So what was perfect for gain, junction capacitance, and tone…was not paying the bills.  Thank goodness these gems pop up from time to time: the glorious 2N3565 glob top, drop dead sexy, Blacktop silicon beauty transistor.

Back to Black

Blacktop Fuzz – Vintage Silicon Muscle.  This Keeley machine is a relatively straight-ahead fuzz.  The magic is in the transistors.  Germanium sounds great if it’s got the perfect gain and is just freshly off-loaded from the freezer.  Again, no Texas Motor Speedway for those old NKT-275 guys.  I like my fuzz a little dark.  I like my fuzz thick and sticky.  Not quite Velcro, but getting there.  I like it sensitive and low noise!  I don’t like noise or hiss!  I want my dynamics to reign supreme.  Tell ya what, these transistors got it babe.

The circuit features one thing I really like, a battery sag switch.  Eric Johnson (a great Texan mind you) hit it right on the head.  The voltage sag makes a difference.  It makes it spongy, softer, more pleasant on the ear.  So we sag the heck out of the supply voltage and give you a nice Yin/Yang thang.  You chose, saggy or tight. Soft or bold.  For Fuzz fans, this is where Eric Johnson meets Joe Bonamassa. Tuned in-between the two.  You never have to worry about it going dead on you when it hits about 90 degrees.  Toss it in your gig bag and know that you have that sound, just right, any time.  That border between germanium and modern silicon, the Vintage Fairchild 2N3565.  The Keeley Blacktop Fuzz – Vintage Silicon Muscle.

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