I checked it out.
It's difficult to find information on that amp here in the US.
Like everybody's said, you wont blow up.
When you use 6 ohm instead of 8, the amp has to work a little bit harder to make things work. If you were to use <4ohm speakers and crank the volume all the way up, all the time, for extended periods of time...then the amp will start to have problems. If I remember correctly, the amp will get hot, it'll start cutting in and out, and possibly even turn itself off to prevent from being damaged.
# Ohms Impedance
Speakers and amplifiers normally have a rated impedance. (Most speakers are around 6-8 Ohms) The lower impedance the more current is used from the amplifier making it more troublesome for an amplifier that is not designed to cope with a lower impedance to drive. A higher impedance is easier for the amplifier to drive and so is less of a worry. Some amplifiers have an impedance selector switch to match the speakers better Ohms: A measurement of resistance. Speakers use ohms to measure their impedance The lower impedance (or amount in ohms) the harder the speakers are to drive. -www.digitaldirectuk.com
I hope this helps a little more.
Reorx