Showing posts with label 2N5172. Show all posts
Showing posts with label 2N5172. Show all posts

Thursday, 7 August 2025

A High-Gain fOXX Tone Machine Clone?



Doom on a Dime_ Temu Fuzz Pedal Review



 Alright, let’s crack this thing open and see what kind of sorcery is packed inside this new version.




What we’ve got here is a surface-mount layout—SMD components all the way. 

But the real surprise? 

This circuit looks eerily familiar… it’s based on the legendary fOXX Tone Machine.

fOXX Tone Machine Schematic

Originally released in 1971, the Tone Machine was a fuzz monster—thick, aggressive, and with a gnarly octave-up mode. It was discontinued in the late '70s.

No frills, no fancy enclosure, just raw fuzz power.

 For under 10€, this is kind of insane.

You won’t find vintage carbon comp resistors or big old caps here—it’s all modern SMD with 4 2N5172 transistors. But if it nails the tone, who cares? 

Not only does this pedal mimic the fOXX Tone Machine’s layout, but it goes further—packing four 2N5172 transistors. That’s more gain, more bite, and potentially more fuzz. It’s like a Tone Machine on steroids.

About the 2N5172

  • Silicon NPN transistor, known for low noise and high gain

  • Common in vintage fuzz circuits like the Big Muff.

  • Adds tight response and aggressive clipping—perfect for doom and sludge.

Gain Comparison: 2N3565 vs 2N5172

TransistorTypical Gain (hFE)Noise LevelTone CharacterCommon Use
2N3565~200–300LowSmooth,
vintage fuzz
Harmonic Percolator,
DIY fuzzes
2N5172~400–500Very LowHigh-gain,
aggressive fuzz
Big Muff clones,
modern fuzz builds

What This Means for Fuzz

  • 2N3565: Medium gain, great for vintage-style fuzz with a bit of texture. Can produce slight octave effects in older units.

  • 2N5172: Higher gain, tighter response, and more saturation. Ideal for doom, sludge, and stacked fuzz tones.

Let’s plug it in and see if it roars.