Re: Battery bias directly to grid



Andre Jute wrote:

> I've posted a circuit for discussion at:
>
> http://members.lycos.co.uk/fiultra/Discussion%20Circuits.htm
>
> What are the implications of this circuit?
>
> What, theoretically, makes it better than the standard battery bias
> application in the cathode circuit?
>
> Will the batteries charge as efficiently in this position as in the
> cathode circuit; what are the effects of the resistors topping and
> tailing the battery set?
>
> What are this circuit's dangers?
>
> Are there alternatives that work better or are safer?
>
> Andre Jute

Unfortunately the images won't appear in the page in either Netscape
or IE.

I have to say I have yet to use a battery in a tube amp for biasing,
but they can work well and unlike even large value electrolytic caps
used for bypassing an Rk the battery remains a low impedance as F falls.

So the battery acts to render the amp a fixed bias amp, with possibly
better bass extension.
But for me the use of batteries isn't warranted since i can easily
achieve a bandwidth down to 5Hz without much phase shift
so any improvement due to batteries might be an illusion.
And the idea of a battery leaking junk liquid all over the internals
isn't nice...

If I could see more of the details I might be able to comment
more appropriately.

Patrick Turner.

.

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