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yoke 19th December 2008 05:11 PM

Powering F series amplifiers from sime power supply
Is it possible to power series of F alike amplifiers from the sime power supply in 3 way active speakerís configuration?
I have notice that F5, F4 and F3 have sime +/-18V requirements on primers so I was thinking maybe to use one power supply to feed all of them in parallel.
For my point of view it would be just like connecting a lot of consumers on sime power line, like when you connect TV, HiFi on the sime 220V, but in this case I would connect F5,F4,F3 on sime +/-18V ?
Iím not EE so sorry if this is stupid question ;-)
Could someone please explain if it's possible.If it is, is there any disadvantage of this setup instead of 3 separate power supply and if it's not possible short explanation why not.


Nelson Pass 19th December 2008 06:39 PM

Of course you can use a single supply for a bunch of these channels, just
make sure the supply has enough current and filtering.


yoke 19th December 2008 06:58 PM

Big Thanks for answer Mr. Pass :D

yoke 21st December 2008 07:53 AM

Just couple more question to clear some things on my mind.

Since we are talking about A class amplifiers (F2, F3, F5...) they all draw the constant amount of current all the time from power source.
From my point of view it doesn't really meter if we talking about bass amp or amp for tweeters.
It doesn't really meter if we, during music reproduction, need more punch for the bass driver or not (the power consumption is constant)
If we would have class AB or B then at the some point bass amplifier would need more or less current from power supply and that oscillation would interfere with other amplifiers in parallel (amp for tweeter) and that would be bad thing.

Now since this is class A and all the amplifiers draw constant current from supply, no meter if it's doing nothing or not, there is no interference be twin those, the work of one amp will not affect other? (power supply constantly supply maximal current needed, we do not have up's and down's ?)

Is this correct?
Is there any other type of interference that could come out? maybe like cross channeling?


Nelson Pass 21st December 2008 06:31 PM

Class A amplifiers (the "pure" kind) all draw an average constant
current from the supply, but this is not necessarily the case at any
given instant.

Your typical PP Class A will draw AC current from the supply, but the
average is a constant.

Your typical single-ended Class A will draw a constant value at all
times from the rail if it is biased with a constant current source -
See the first Zen amp as the example.

Balanced single-ended and push pull designs tend to draw constant
current, Son of Zen being a simple example.


yoke 22nd December 2008 06:23 AM

Thank you very much

I think I get it now, not 100%, but I think I'm on right way to get it ;-)...will have to read once more some articles about those amps ;-).

Thanks once again

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