The JTM 68 MKIII borrows its features and design from the 50 watt Plexi Marshall with diode rectification from 1968. It comes with a classic ECC83 preamp and as is standard on all Gladius amps, the unique Variac power reduction which allows the user to scale smoothly from 0.1 watts up to 50 watts (continuously variable). Of course, it is hand-wired and equipped only with the best components. The Rhythm & Lead circuits can be switched by a foot pedal which, in rhythm mode keeps even the fattest Les Paul clean and generates in lead mode the original singing heavy rock tone. By switching from lead to rhythm (hence the foot switch connection) the amplification is reduced to such an extent that the amp turns 'clean' without the slightest loss of volume or even definition. Using the rhythm circuit, you can play the amp real tight, without getting the usual sludgy sound when playing a Humbucker-guitar, (an often criticized aspect of vintage amps). In combination with the Gladius cabinets, the amp can be played clean even at a level of 0.1 watts without loss of tone.
An indispensable extra feature is the channel-patch that internally combines both channels (bright and normal) without having to use a conventional external patch cable. Plugging into either the Hi or Lo inputs patches your signal to both the bright and normal channels which can then be controlled via their respective volume knobs. With an AB switch however, all inputs can be applied separately.
With the rhythm-lead function (clearly visible through different colors on the pilot light) as well as with the two different inputs, you get 4 completely different sounds!
As the name already suggests, in this setting the complete vintage sound up to 1968 is covered. It is extremely fat, round and smacky in response with heavy distortion as used by Billy Gibbons, Jimmy Hendrix and Jeff Beck.
With this setting you will get a clean and very stable tone similar to a Plexi 100, open however, without the vintage character. This cicuit is explosively quick in response, without sounding harsh; fat and round but mercilessly defined, like with Eddie van Halen, or Joe Bonamassa, Slash and many others.
The JTM68 MKIII has a couple of basic settings:
Vintage setting (all controls in the middle position): With this setting the full vintage sound of 1968 comes alive. Extremely bold, round and dynamic, with lots of dirt, just like Billy Gibbons, Jimi Hendrix, or Jeff Beck.
Classic setting (bass to 0, all other controls fully on): With this setting you get a tighter open sound, with less vintage character. Its explosive attack is always well defined without getting harsh or overly aggressive. Examples: Eddie Van Halen, Joe Bonamassa or Slash.
The Gladius JTM models are classic tube amplifiers featuring different design details like output transformers and power tubes. The amplifiers are hand wired and have an aluminium chassis with aluminium end-blocks.
- Type: class AB
- Output power: < 0.1 W - 50 W (controlled by Variac)
- Power amp: 2 x EL34
- Preamp: 3 x ECC83
- Rectifier: solid-state
- Output transformer: 784-139
- Inputs: Hi & Lo (each with internal gain patch to both channels)
- Input controls: Presence, Bass, Middle, Treble, Volume
- Speaker connectors: 2
- Speaker impedance: 4/8/16 ohms switchable
- Output power control: continuously variable
- Color: black
- Mains voltage: 117 V~ / 230 V~ 45-60 Hz
- Power consumption: 175 VA max.
- Weight: 15 kg
- Dimensions: 21" x 8" x 9" (53cm x 21cm x 23cm)
- Special features: integrated channel bridge, Gladius output power control, rhythm & lead circuit with foot switch connector on the back panel
- Option: connector for effect devices on the back panel