Dosent the transformer provide the gain function? Then it aint 600:600???
I have a couple LL7905 (4x150 Primaries) to be driven by a B1 type circuit. The output will be the two secondaries on a BA-2/F4 output stage. Gain should be 5.6 or something. These Xfrm'rs are not inexpensive. There is no garuntee I will get the bandwidth I need but... And no garuntee they will sound good but... I'm gonna play around. Might get good midrange performance.
Genreg has suggested some lesser expensive units that he liked. And Nelson has said he got good results with some units that you might not expect good results from.
You probably want to make sure the levels you need are capable with the mic transformer.
I have a couple LL7905 (4x150 Primaries) to be driven by a B1 type circuit. The output will be the two secondaries on a BA-2/F4 output stage. Gain should be 5.6 or something. These Xfrm'rs are not inexpensive. There is no garuntee I will get the bandwidth I need but... And no garuntee they will sound good but... I'm gonna play around. Might get good midrange performance.
Genreg has suggested some lesser expensive units that he liked. And Nelson has said he got good results with some units that you might not expect good results from.
You probably want to make sure the levels you need are capable with the mic transformer.
One of the charms about the transformer vs JLH/PLH phase splitter is that
it delivers pure symmetry in the same way a circlotron does - each like
polarity part is subjected to the same conditions, although in opposite
phase.
It is possible to do this with a phase splitter ala JLH/PLH, but if you look
carefully you will see that the bottom output device is run Common-Source
mode and the top device is Common-Drain. It is a rare circuit that will
deliver real symmetry under these conditions.
One of the charms about the transformer vs JLH/PLH phase splitter is that
it delivers pure symmetry in the same way a circlotron does - each like
polarity part is subjected to the same conditions, although in opposite
phase.
It is possible to do this with a phase splitter ala JLH/PLH, but if you look
carefully you will see that the bottom output device is run Common-Source
mode and the top device is Common-Drain. It is a rare circuit that will
deliver real symmetry under these conditions.
Yup. The question is whether a transformer can do better than swinging around the power supplies in the circlotron. My bet is that it can.
My understanding of the JLH, is the phase splitter provides gain to the common drain output (top) and no gain to the common source device (bottom) which provides it's own gain. So theoretically it should be possible to construct it so that the gain going to the source follower output is equal to the gain that the common source output provides by itself. Assuming that is what you wanted to achieve
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Very cool. Class in session. Apparently i am the only one surprised or impressed, post hoc, that is..One of the charms about the transformer vs JLH/PLH phase splitter is that
it delivers pure symmetry in the same way a circlotron does - each like
polarity part is subjected to the same conditions, although in opposite
phase.
It is possible to do this with a phase splitter ala JLH/PLH, but if you look
carefully you will see that the bottom output device is run Common-Source
mode and the top device is Common-Drain. It is a rare circuit that will
deliver real symmetry under these conditions.
A clarification by Mr. Pass is important. Are the signals acting in phase on the FETs or not? The old style technology of OTL was NOT,and the bjt semiconductors needed to be matched which will be guaranteed in F6. But suppose the answer is YES. ZEN MOD you began analyzing its operation [bolded],and may need to continue to explain it further for our benefit.Pa , please clarify .
I'm dumb ........ I can't see any meaning in driving both gates in phase , if that's meaning of "matched" ;
I certainly didn't look at first post pic thoroughly ......... and now I see that secondaries are really connected to drive gates in phase ........
if yes , then upper and lower modulation must be different in amplitude , intentionally ........
off course , there is always possibility that you're pullin' da leg of poor ZM
...it delivers pure symmetry in the same way a circlotron does - each like polarity part is subjected to the same conditions, although in opposite phase... ...It is a rare circuit that will deliver real symmetry under these conditions.
How exactly does that happen? I see that the secondaries are refrenced to the Source's. So the output transistors recieve the same signal but, we are taking a Drain output from common source and a source follower output and "summing" them. Those aren't the same conditions? There are a few peices missing?
My question concerns the effect of the output fets operation on the signal. Sy stated in his Impasse article that a phase splitter was symmetrical if presented with a symmetrical load, but if the two loads were different, then it affected the tru symmetrical nature of the phase splitter. I think you see an exampl of this in the PLH. IT is a phase splitter, but i it is not driving equal loads, as you have a common drain and common source outputs summing into the load. THe transformer presents symmetrical signals out of phase to the two output fets, but they still will react differently to that signal,,, I would think.