F5 Turbo Circuit Boards

[AudioSan]

Originally Posted by a.wayne

@ AudioSan ..

Spare me , my last Class-a amp drew 1400 watts from the wall at idle ... I have walked this Forrest before ....

without fans? or watercooling?

[a.wayne]

Originally Posted by lhquam

If the mono-blocks were square, then you could stack them with one rotated 90 degrees relative to to other and not have the heatsink air-flow compromised for the mono-block on top.

should look lovely ....

Originally Posted by labjr

Well, I can't imagine why else anyone wouldn't want boards which will benefit more people since it seems impractical to have a board with 8 outputs on it running high bias class A. Will run too hot. Only make sense to me that many will be discouraged from building something so complex in one chassis. Obviously, it isn't gonna be a project for frugal builders. So the easier it is to build, the more interest it will attract.

AGAIN !!!! ...

I'm not against any of this, I was address Mr San's redonculous statement that it would be cheaper, it is not, i don't care if toe made a PCB for each output , personally i would prefer 14 outputs /ch , yeah , maybe i will push for that , this way we could choose 2/4/8/12/14 ...


Being serious as JV, i could use more outputs , what say you .....

[a.wayne]

Originally Posted by AudioSan

without fans? or watercooling?

No fans , Krell KSA200 ........

[AudioSan]

Originally Posted by a.wayne

No fans , Krell KSA200 ........

Krell KSA-200S
Krell's new KSA-200S is a large stereo chassis, conservatively rated at 200Wpc into 8 ohms (23dBW). The rating continues to double down to a 1 ohm loading, where a 1600Wpc output is specified. Krell's proprietary output-stage bias system delivers dynamic class-A operation up to the maximum 8 ohm power rating, with an increasing proportion of class-AB operation with the higher current associated with lower load impedances. This "Sustained Plateau" biasing scheme is said to offer the sonic benefits of pure class-A without the massive energy inefficiency and correspondingly huge, hot heatsinks. The energy-conscious KSA-200S idles at 120W. If it ran in pure class-A, it would have to idle at around 1kW—over eight times as much wasted energy drawn from the wall.

funny that the 200S only idles at 120W?

[AudioSan]

and so big sinks

[a.wayne]

No, not that one , the one before , the real 200 watt class-a . that one is not full a full class-a 200watter , it has "plateau Bias"....

This one ...

[tehrkn]

Please include me for 4 amp and 8 PS boards.

Thanks a lot.

[AudioSan]

that was some monster heatsinks to.
need to be 0.017C/W total.
guess it is 600-700mm deep?

[jacco vermeulen]

0.325A bias per Motorola, 77Vdc rails, makes 25W.
Six on each heatsink, 36 total, makes 900W dissipation.

The heatsinks Krell used on the 200B are 0.30C/W, so they ran stupidly hot.
Why they broke down so often.

Now back to our regular scheduled program.

[AudioSan]

Originally Posted by jacco vermeulen

0.325A bias per Motorola, 77Vdc rails, makes 25W.
Six on each heatsink, 36 total, makes 900W dissipation.

The heatsinks Krell used on the 200B are 0.30C/W, so they ran stupidly hot.
Why they broke down so often.

Now back to our regular scheduled program.

that tells it all i wonder. had that happend with monoblocks at 2/3 the hight and same sink type and depht? no.