Guitar amplifier AMT SH-100R
Quick start
A little bit of history
For AMT the quest to reproduce tube amp characteristics in a foot pedal began about 10 years ago. Our
engineers discovered a way to create a "tube" like sound using cascade modeling semiconductor devices
and the design of the first “Legend Amps” series began.
LA-1.
With the release in 2008 of the first Legend Amps pedals, guitarists got the opportunity to have
at their disposal compact pedals simulating preamplifier overloads which became legendary for guitar
players. Cascades with JFET transistors and Schottky diodes were the base for overloading and grid
limiting.
LA-2.
During the next several years, the AMT engineers were working on improvements of the first
series, taking in mind “non ideality” of the first series modeling, and a new series appeared in 2012.
The list of modeled amps was significantly expanded,a new and effective way of "triode" limiting was
applied,and the schematic of a cabinet simulation became more complicated.The additional drive output
was implemented, that gave the opportunity to plug the device directly to the input of an amplifier’s Clean
channel and use the LA-2 series device as a drive pedal.
However, despite the obvious successes, the quality of emulation in terms of full compliance with the
originals left much to be desired, primarily due to restrictions on the supply voltage (recall pedals are
powered by a voltage source + 9..12V). Increasing the voltage in the preamp SS-30 "Bulava" and the
amplifier StoneHead-50 helped in many ways to get rid of these limitations and improved the brightness
and dynamics of the sound.
The power amplifier “StoneHead” SH50-4 can be called the “crowning” of the emulation technology
applied in the LA-2 series. It is no coincidence it was warmly accepted by the guitar community and many
guitarists are happy to use this compact, lightweight, and functional power amplifier in rehearsals and on
tour..
But despite the restrictions due to low voltage, which makes the emulation of LA-2 not ideal, there is a
fact that LA-
2 emulates only tube limitations without taking in mind the “triodeness” of voltage-current
characteristics inherent to real tubes, which significantly impacts the overall sound
LA-3.
The development in 2013 of solid-state analogues of 12AX7 tubes has created the basis for the
emergence of solid-state preamps, virtually copying the behavior of tube prototypes and giving impetus to
the development in 2014 of micro-triodes (basic of LA-3 series), i.e., the devices with the voltage-current
characteristics which are miniature replicas of the characteristics of the vacuum triode. A lot of work had
been done during 2014 to make the micro-triodes have characteristics which have a complete vacuum
prototypes’ identity (including scale). In 2015 the company began to develop a new LA-3 line.
Some words about micro-triodes.
The new AMT analog modeling technology is based on the use of micro-triodes, which have reduced
copies of the electrical characteristics of real vacuum tubes. You can take an image of the anode
characteristics of a conventional "guitar" ESS83 (12AX7) and compare them with the following picture,
which shows the AMT micro-triode "anode" curves and make sure that the forms are almost identical and
differ only in scale.
