The AMT SS-20 is a two-channel tube guitar preamp from AMT Electronics, built around a single 12AX7 tube and aimed at players who want amp-style clean and overdriven sounds in a floor unit. AMT positions it as a brother to the SS-11 preamp, but voiced for what the maker calls "tighter, crunchier, more aggressive styles of guitar playing"1. It is an analog preamp with Clean, low-gain and high-gain modes, and it is currently listed as available1.
What the SS-20 does
The SS-20 is a preamp, not a distortion pedal: it is meant to shape your core tone the way an amp's front end does, feeding either a power amp or a recording device. AMT says the unit uses special cascades capable of reaching 250V amplitude with nonlinearity similar to a 12AX7 triode, which eliminates signal-limiting op-amps in the preliminary amplification stages1. The 12AX7 itself runs at a DC 290V anode voltage, a real amp-level operating point rather than the low starved-plate voltages common in tube-branded pedals1.
The maker's demo material shows the SS-20 driving a Laney Lionheart power amp with a Les Paul, which is the classic preamp-plus-power-amp setup this kind of unit is designed for2.
Channels, modes and footswitches
The SS-20 has two channels, CLEAN and DRIVE, with the Drive channel operating in two basic modes1:
| Channel or switch | What it does |
|---|---|
| CLEAN | Clean channel |
| DRIVE, CRUNCH mode | Drive channel at moderate sensitivity |
| DRIVE, LEAD mode | Drive channel at high sensitivity |
| Left F Switch | Turns the DRIVE effect on and off |
| Right F Switch | Turns the DISTORTION effect on and off |
In LEAD mode, with the Gain LEAD control set higher than 7, AMT states that a semi-conductor part participates in the sound limitation, so the top end of the gain range blends solid-state clipping with the tube stage1.
Beyond the channels, the SS-20 carries a global Noise Gate, a Power Amp section with 9 types, a Parametric Pre/Post EQ, and an IR cabsim with one IR shared by both L/R channels per preset234.
Power and connections
The SS-20 runs on an external adaptor with an AC 120V to 240V input delivering 12V DC at 1.25A1. There is no battery option.
The 1.25A current draw at 12V is well beyond what a typical shared pedalboard daisy chain provides, so the SS-20 needs its own adaptor rather than sharing a supply with other pedals.
On the connection side, the unit has an Input, an Amplifier Output carrying the direct, unaltered signal for amp heads, combos and speaker cabinets, and a speaker-compensated Mixer Output for mixing consoles, computers and other recording devices1. That second output is what lets the SS-20 work as a direct recording and live-di solution without a guitar amp in the chain.
The SS-20 and the SS-11
AMT describes the SS-20 as a brother to the SS-11 preamp, with the SS-20 designed around tighter, crunchier, more aggressive playing styles1. Both are analog preamps offering Clean, low-gain and high-gain operation25, so the practical difference is voicing and gain character rather than architecture. AMT's media center also carries a Dennis V. Epov improvisation video on the SS-11 showing the sibling preamp in a medium funky context, a useful contrast with the SS-20's harder-edged demos51.
What reviewers and players said
Published third-party reviews of the SS-20 are thin, and what exists comes mostly from AMT's own media center. The maker's page lists a complete review video dated 17 July 2015 and a demo titled "SS-20 Les Paul direct," and its product page carries a "THIS PRODUCT USED BY MUSICIANS" section, though without named players13. A further maker demo shows the SS-20 with an Agile Intrepid 830 eight-string in a metal context, consistent with the unit's aggressive positioning4.
Videos
Brett Kingman
Brett Kingman
Brutal Gain
Questions
Does the AMT SS-20 have a real tube?
Yes. The SS-20 uses one 12AX7 tube, run at a 290V DC anode voltage, which is a real tube stage rather than a marketing badge. AMT also states that its preliminary amplification uses special cascades capable of reaching 250V amplitude with nonlinearity similar to a 12AX7 triode, so the tube is working at high voltage.
Can the AMT SS-20 go straight into a mixer or audio interface?
Yes. The SS-20 has two outputs: an Amplifier Output that passes a direct, unaltered signal for amp heads, combos and speaker cabinets, and a speaker-cabinet-compensated Mixer Output for mixing consoles, computers and other recording devices. That means you can record or run front-of-house without a guitar amp.
What is the difference between the AMT SS-20 and SS-11?
AMT describes the SS-20 as a brother to the SS-11 preamp, but designed around tighter, crunchier, more aggressive styles of guitar playing. Both are analog preamps with Clean, low-gain and high-gain modes, but the SS-20 is voiced for harder-edged material.
Does the AMT SS-20 run on batteries?
No. The SS-20 is powered by an external adaptor, AC 120V to 240V input delivering 12V DC at 1.25A. There is no battery option, so you need the supplied power supply or a compatible 12V source.
Sources (5)
- AMT SS-20 (Studio Series preamp), AMT Electronics, 2026
- AMT SS-20 Guitar Preamp: To Laney Lionheart power amp, Media center of AMT Electronics
- AMT SS-20, AMT Electronics media center, 2016-05-06
- Agile Intrepid 830 + AMT SS20, Media center of AMT Electronics
- Dennis V. Epov, Media center of AMT Electronics
