Digital amp update

[Andrew Pratt]

I was talking with Rotel the other day and inquired about the status of the digital amps. Apparently they're still tweaking them a bit but we should see them sometime in the middle of summer (Early July give or take a bit)

[aud19]

Are they planning on selling the solid-state amps alongside the new digitals or are they fasing the SS's out?

[Andrew Pratt]

Yes. I was told Rotel will continue to sell the regular amps for some time to come.

[Kens1]

I remember reading about this before, Andrew do you recall if they were planning on making one of those digital amps a 3 channel model?

[Fishy]

Well if Rotel (UK) want someone the try them out, just give them my mail address.

Fish

[Andrew Pratt]

I'm not sure...I know there's a 7 channel version, a 2 channel and a high power mono but there could well be others as well

[csuzor]

Could you explain what a digital amp is, how is it different, what advantages can we expect? Or point me to such info?
Thanks
Christophe

[mjb]

Digital amps (class D) is for audio what switch mode is for power supplies. The amp has only two states: full on and full off. By 'chopping' these states very fast (using 'pulse width modulation'), huge power vs. size/weight can be achieved with very little heat. The on/off transitions occur around 350,000 times per second, which makes the brain think its in-fact hearing continuous audio!

Class D amps are totally linear and very efficient. The downside is, thanks to all this switching, they produce lots of high (radio) frequency noise which must be filtered.

[nash]

I believe the 7 channel is 100W (7x100) - do we have specs yet on the 2 channel?

[Aussie Geoff]

Hi,

The on/off transitions occur around 350,000 times per second, which makes the brain think its in-fact hearing continuous audio!

Even better - hi fi quality digital amps filter the output signal to remove the digital transtions completely so that the actual signal you get out is analog and matches the imput signal (they have a roll off at between 20Kz and 100+Khz depending on the technology). Bottom line - the output from a good digital amp looks the same electicaly as that from a good analog amp (continuous wave forms in the 10Hz to 20+KHz range

Geoff

[csuzor]

huge power vs. size/weight can be achieved with very little heat.

OK, thanks for the info guys. Is this the only advantage, a smaller package and less heat for more power? Do you expect other benefits?
Thanks