audio-talk

Well we both know they seem to sound better on breadboards anyway. Not sure when the putting in boxes crept in.

I dont agree with Sowter when you wind a power transformer you choose the core size by the power only half the centre tapped winding is working at a time. So the current through half the winding is taken into account. The core and A which is the core suface area is measured for that duty. Which is ...

So from the link Max gave

FULL WAVE: Iac = Idc

BRIDGE: Iac = Idc x 1.61

So from that I would say that the rating of a transformer rated for full wave should be de-rated by 62% (1 / 1.61 = 0.62 )

Yes the TT supply. Generally 3886 are better. They are very reliable as long as you drive them with care. I found TDA types would literally go bang.

Well I can imagine a amp getting upset driving the output tx. It will look like a short at DC and transients could cause back emf problems. I would advise against it. I drive a transformer secondary with a 3886 and had to learn a few tricks to stop it blowing up.

Its most likely going to be the TDA, but just make sure that the voltage lines had got above the min voltage those chip amps need. Its caught me out before that if they have too low a supply rail they do odd things like output a DC offset.

Just one thing to consider from your post Max. *sn7 is not that far from a 5687 (lower transconductance, but not that big a deal in this case), so I would consider using that to drive that interstage as well. *bx7 is closer to a 5687, but don't rule the sn7 out. Especially in conditions where ...

That interstage should be ideal. But as I said, no DC with mumetal/nickle, so the parafeed shape would work nicely.

Just one thing to consider from your post Max. *sn7 is not that far from a 5687 (lower transconductance, but not that big a deal in this case), so I would consider using that to drive ...

I dont thing China was at the conversations in Kioto.

I think you would probably be thinging wrong. China is doing more than many to reduce its CO2 impact.

https://en.wikipedia.org/wiki/Climate_change_in_China

"China is currently a member of the United Nations Framework Convention on Climate ...

Couple of 1000v depletion mosfets in series will do just fine. Again, they only need to be close to ideal because of the balanced nature. I used a couple of
IXCP10M45's in the preamp. They are good for 450v.

Remember I am talking about driving a interstage here, not a power output stage.

But hey ...

I would imagine the CCSs supply the current for the signal alternatively.

But where does the current go? The total of both anode currents is constant as the individual anode currents are constant, they have CCS's in series with the, And the anode currents are summed by the cathode resistor, so ...

Parafeed removes DC. But using a CCS load becomes interesting when you try and consider where the current comes from to create the dI/dt in the primary.

Interesting doc. Also have you tried any of the phase change insulating pads (like Hi-Flow 625), I have found they are better than SP400 types.

TBH, no idea whats going on there with the "cascode". All I can say, is that for the parafeed output, the CCS's connect to the anode of the valves, the other side of each primary windings.

The balanced parafeed output has been removed from the Ravel Mk-2, but the schematic is still on Sowters site. Just a shame Sowter don't want to wind the original transformers. But any interstage with two separate primaries would work. For that matter with a single primary, but the balance won't be ...