The Amptweaker TightMetal ST is a high-gain metal distortion pedal that takes the original TightMetal circuit and adds Amptweaker's SideTrak loop, a second effects loop that works only while the pedal is switched off1. It is built by Amptweaker, the company of amp engineer James Brown, and the original TightMetal was designed with Mark Kloeppel, guitarist of the deathgrind band Misery Index12. The pedal combines three functions in one box: distortion, a looper and a noise gate1.
RockBoard's PedalPedia describes the circuit's approach in amp terms: "In the same way high gain tube amps are designed by cascading extra tube stages, the TightMetal was created by adding additional stages," resulting in what RockBoard's PedalPedia calls thicker and much heavier distortion1.
What it does and how it is controlled
The TightMetal ST carries over the TightMetal's over-the-top metal and hardcore crunch tones and adds the SideTrak loop1. The core of the sound shaping is the Tight Attack control, which the manual sums up as letting "YOU dial in the chunk"2. Around it sit a set of switches:
| Control | What it does |
|---|---|
| Tight Attack knob | Sets the attack character of the distortion, from loose to chunky2 |
| Mid switch | Enables the Thrash EQ setting3 |
| Gate switch | Activates chomp mode on the noise gate3 |
| Internal Fat switch | Warmer rhythm and/or boost tone3 |
| Recessed EFX loop switch | Sets the main effects loop to pre or post3 |
| Battery switch | Disconnects the battery when using a mains adapter3 |
| Bypass footswitch | Switches the pedal on and off3 |
The main series effects loop can be set for Pre or Post positioning in the effects chain, a feature Amptweaker carried across its distortion line; Premier Guitar noted the same arrangement on the original TightMetal4. Input impedance is 100K Ohm and output impedance 1K Ohm with the effect on2.
The SideTrak loop
The SideTrak loop is the feature that separates the ST from the standard TightMetal. It is a secondary loop that only works when the TightMetal ST is OFF12. In practice, you patch a second effect into it, a clean boost, an EQ or anything else you want in your clean sound, and that effect is active while the pedal is bypassed. Stomp the TightMetal ST on and the SideTrak loop drops out along with whatever is connected to it, leaving only the distortion.
Amptweaker has since expanded the idea: the current Tight Metal Pro II carries three effect loops, labeled Global, Boost and Side Track5.
Power: 9V to 18V, and what the voltage changes
The pedal runs on a 9V to 18V DC adapter with a 5.5mm x 2.1mm barrel, center negative, or on a 9V battery123. Current draw depends on how you power it: 14mA with a 9V battery, 20mA with a 9V adapter, and 45mA with an 18V adapter, the extra draw coming from the knob LEDs the adapter powers2.
The manual is specific about what the higher voltage does to the tone: "9V sounds like a 50W amp tone while 18V is a cleaner, louder 100W tone. Like a variac!"2
The 18V setting draws 45mA because the adapter also lights the knob LEDs, roughly triple the battery figure. If you run the pedal on a shared or daisy-chain supply, budget for the adapter current draw, not the battery number2.
A version of the original TightMetal
The TightMetal ST is a variant of the TightMetal, a high gain metal distortion originally designed with Mark Kloeppel, guitarist of the deathgrind band Misery Index1. Reviewing the original, Premier Guitar described it as tending "toward the thrashier side of the sound rainbow"4.
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Questions
Is the Amptweaker TightMetal ST true bypass?
Yes. The manual specifies True Bypass switching, buffered when the pedal is ON. That means the signal passes straight through when the pedal is off, and a buffer is engaged in the active signal path while you are playing through it.
What is the SideTrak loop on Amptweaker pedals?
SideTrak is a second effects loop that only works when the pedal is OFF. You can plug another effect into it, for example a clean boost or EQ, and that effect is heard only in your clean sound. When you stomp the TightMetal ST on, the SideTrak loop is bypassed along with whatever is connected to it.
Does the TightMetal ST work when the pedal is off?
The distortion itself does not, since the pedal is true bypass when off. But the SideTrak loop does: it is a secondary loop that only works when the TightMetal ST is OFF, so effects patched into it stay active in your clean signal while the pedal is disengaged.
How much does the TightMetal ST weigh?
The Amptweaker manual lists the weight as 2 pounds, with dimensions of 3.75 inches wide by 5 inches deep by 2 inches high. The housing is 14 gauge galvanized steel, and each pedal is handmade in the USA.
Sources (5)
- Tight Metal ST by Amptweaker, RockBoard (rockboard.de), 2026
- TightMetal ST web Manual.pages, Amptweaker, LLC, 2018
- Amptweaker TightMetal ST Pedal, iMuso
- Amptweaker TightMetal Pedal Review, Premier Guitar, 2011-09-20
- Tight Metal Pro II, amptweaker.com, 2026-04-16
