[sdiy] Urei 1176 old version single ended output - how does it work?

[René Schmitz]

Hi Jürgen and List,

JH. wrote:
> Thanks Rene, I wasn't aware there might be other benefits (than DC
> compensation)
> for such a configuration. Looking at the Quad schemos what you say makes
> perfect sense: So the Urei  is most probably a typical single ended
> configuration with air gap transformer.

If you keep the magnetisation well below the maximum the core can handle 
(1.2-1.6 Tesla depending on the material), you might get away without an 
air gap.

> This still makes me think about a circuit where one winding is bypassed
> by a large electrolytic, in order to provide DC compensation. I don't
> know if there would be any benefit over simple AC coupling (with a
> similarly sized electrolytic), though.

If you bypass one winding with a cap, you essentially short it and thats 
not a good idea. The winding would dissipate a lot of your energy.
What you could do instead, is to run a DC current from a current source 
through a second winding. This is more or less a push pull amp where 
only one side is driven by audio. (But then it would be easy to turn it 
into a real PP amp.)

Parafeed (AC coupling) is another way, but you need to raise Ub two 
times, to get the same power output than before.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159