"flipper" <flipper@[EMAIL PROTECTED]
> wrote in message
news:rj3p24pftvlhtc0rq52fs49e4te0e5aibv@[EMAIL PROTECTED]
> I've been toying with the idea of building a tube phono preamp and
> using DC heaters but, as you all probably noticed from my last few
> projects, I want to power the thing with a wallwart. That presented
> the regulator drop out problem so I whipped up a '0V dropout'
> regulator.
>
> Thought I remembered seeing others discuss that same issue (like
> converting an existing amp with 12.6V transformer) so I posted the
> schematic to my website in case anyone is interested.
>
> http://flipperhome.dyndns.org
>
> Not fancy and it doesn't have soft start but that could be easily
> added.
>
> I haven't built it yet but spice says the sucker should regulate to
> better than 100uV ripple, which should be ridiculously good for a
> heater.
This will work just fine although, as you said on your webpage, you may
need
to do a little compensation if there's any tendency towards instability.
I've built many of these in the past, except that my particular versions
use
a bipolar transistor and a TL431 in place of your zener and opamp.
Best Regards : Doug Bannard
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