David Gravereaux wrote: > Ian bell wrote: > >>David Gravereaux wrote: >> >>>That's a push-pull arrangement. As the ripple is identical and both tubes >>>have >>>matched gain, the ripple noise cancels in the transformer. >>> >> >> >>Are you sure about that? > > > Yes. > > >>Each valve conducts for only half a cycle. > > > Not true. You forgot about the class-A range of overlap. 30% overlap isn't > uncommon. It's only at low output level where PSU ripple is a concern. >
Debatable on all counts. Unless it is pure class A, there will be parts of each cycle where only one valve is conducting. Unless the PSU is fully regulated ripple will increase with increasing signal. Ripple to signal ratio is likely to be similar at all signal levels. > >>It >>is like summing two single ended amps fed with anti-phase inputs. Each >>is still affected by ripple. > > > Yes, and they cancel in the transformer. > I don't see how they can. I'll need to go simulate it to check it out. > Is this topic done yet? I'm done with it. > I'm not. It's interesting. Ian
