>Lets try a different approach.
>
>I´ve built two DAF amps. The third is on its way. I cant guarantee that the
measurements I´ve done are 100 percent
>sientific, but they all point in the same direction.
>
>* On air tests
>* Two tone measurements
>* Spectrum analyze of voicesample
>
>All showing good to excellent linearity and some of you have already seen
those plots. Am I wrong?
>I dont claim class C efficiency, rather about the same as AB2.
>
>I´ve not put any effort into selecting timeconstant in screen filtering, so my
guess is that it´s not especially critical.
>Anyhow, to describe exactly how the DAF circuit operate is quite complex. I
can´t do that, but I do know that it works,
>and works fine! In SM there are 4 or five more DAF amps active on the bands,
and in my opinion they all sound good and
>do not splatter. And I consider myself to be quite critical when it comes to
splatter and broad signals.
>
>Putting an equalsign between DAF and class C is definitely wrong!
>
>I´m not saying that DAF is so much better than everything else, maybe just as
good, and apart from that; a clever design.
>
>So if anyone, in a constructive matter, could bring a bit more light in how
the DAF ckt operates electrically when it comes to
>linear amplification, I´ll be very interested. If not, I guess we have reached
the far end on this subject!
>
>Now, I´ll go back to my #3 project. Have some work to do!
>
>73 de Lars/SM3BDZ
>
>
I have heard both SM3BDZ and SM2CEW (both using DAF with QBL-tubes) many
many times for more then a year now and both sounds excelent and have no
splatter so those two DAF-amps do work. I have also heard one or two
other G2DAFs that didn´t work (SM3DOT and SM3EXO i think it was), they
had a very big bandwith (splattering). So obviously there are ways
to get the design to perform correct.
I think it´s getting abouth time to try a DAF-amp myself, have a lot
of QBL tubes collecting dust in the basement.
73, Jim SM2EKM
Ps: How about 4-1000A in a G2DAF amp, would that tube work?
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