Gamut M250i User Manual - Page 5

Browse online or download pdf User Manual for Amplifier Gamut M250i. Gamut M250i 13 pages. Mono power amplifer

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Cleaning the cabinet

The front panel is made of aluminium. It can be cleaned by using normal mild solvents and clean

paper tissue or cloth. Do not use excessive amounts of solvents, and do not let any of the solvent

spill into the ampli er.

The ideas for the protection circuit comes from our professional ampli ers, where it has worked

well since 1982. Due to the rugged MOSFET, we can allow high peak currents , and we only need

to mute the input signal in case of longterm overload.

The protection detects DC errors, high level subsonic signals, long-term ultrasonic signals, high

temperature, and to low impedance loads or short circuits.

If needed, the protection will simply mute the input signal, and if necessary open the output relay.

The relay will normally open only after muting the input signal to avoid relay switching of strong

currents that could corrode the relay contacts.

So in case of i.e. a short circuit the input is muted for a second. Then a 1 millisecond long pulse is

sent out to test again. If the short circuit still is present, it waits a second and tries again, and so on.

One second after the user has removed the faulty cable, the system will quickly remove the muting.

The protection also detects too low impedance loads, and alerts the user by muting for a second.

So the user can be sure to hear only clean non-distorted audio. The normal current limiting and

momentary distortions of the music are avoided in the GamuT M250 power ampli er.

You may experience a second of silence while the music is playing loudly. This is the protection

acting to protect your tweeters. Any ampli er will start to clip the top of the music if you exceed

the maximum power level. Technically, clipping generates a lot of high frequency energy, which

can burn out the tweeters in your loudspeakers. The protection constantly checks the energy

above 20 kHz, which humans do not hear. The distortion is momentarily very high anyway,

because you have exceeded the maximum power, so just reduce the level a bit.

You can also provoke the subsonic protection by playing warped records without using a

subsonic lter. Please check your tonearm/cartridge resonance frequency, which should be about

8-12 Hz to reduce the e ect of warped records.