The Metal Master with gain dialed up produces a heavy metal guitar tone typical of Led Zepplin, Deep Purple and Black Sabbath.
Despite the name, this mini amp can produce a warm clean sound when set to lower gain levels and the tone can be varied widely with its effective EQ. When desired it will blare out 1980s style screaming metal with the gain turned up. Overall it makes a great head for practice amp or recording DI or as an effect unit in a pedal chain. The
Metal Master is the same form factor as the other
Hughes & Kettner "Sound Machine" low power amps. It is equipped with two 12AX7 (ECC83) valves in the pre-amp, 3 EQ bands and a 4.5W solid-state power amp, which drives speakers through the speaker output. As can be seen in the photo at the right, it is has a wide range of output jacks. These include: tube amp out, instrument out, mix out, cabinetular out (similar in function to a H & K RedBox) and speaker out. It even contains a switchable headphone jack, which makes the unit ideal as a fully featured amp for for quiet practice. Certainly better than those "toy like" practice amps currently available.
4.5W solid-state output transformer
120V AC and 240V / 220V versions
Guitar amp input Instrument
Power amp Line
Tape machine Line
Mixing desk Line or instrument
Stereo system Line
16. Mix Out
20. Headphone On / Off Switch
The controls, switches, jacks etc. of the Metal Shredder (U.S. name)/Metal Master (European name) are nearly identical to those of the Cream Machine and Blues Master/Crunch Master. The instructions for using the Metal Shredder/Metal Master are therefore the same, with the following exceptions:
As with the Cream Machine and the Blues Master/Crunch Master, the BYPASS output signal will function with or without the Cabinet Simulator circuitry, or switched off. Internal switches are used to set the BYPASS functions between Off or On with no Simulator filtering or ON with Simulator filtering.
To set the desired BYPASS function to one of the operating three modes, follow the switch setting diagrams below:
The internal Bypass switches can be seen in the photo below. They are the two red switches with black slides. They are set as per the instructions above.
Below can be seen the two 12AX7 valves used in the preamp section. Note the cooling vents under the tubes. It is important not to block the bottom airflow to the vents.
To the right of the valves is the output transformer. The three large cylinders are high-quality electrolytic capacitors. The upright black and blue jacketed cylinders are smaller electrolytic capacitors.
The BD237 (NPN) and BD238 (PNP) are a pair of "sink cooled" medium power transistors. The black potentiometer in between those two components is for setting the bias. The part to the right of the potentiometer is a TL081 JFET op amp, which I am guessing is used to produce distortion.