Hi Jaap, yes, you could certainly try it, though whether you need it very much will depend on the type of output valve.
But with all closed-loop systems, please take care to see that frequency compensation is correctly applied.
I imagine that you are using a high-performance, wide-bandwidth transformer - it will be needed!
Place the compensation cap in parallel with the output resistor. Take care that ferrite-beads are present on all the susceptible nodes (anode, PNP base & collector), and that they are lower-frequency types - losses in the 500kHz-10MHz range are needed for these.
screen the feedback wire, and keep all of the circuit small.
But with all closed-loop systems, please take care to see that frequency compensation is correctly applied.
I imagine that you are using a high-performance, wide-bandwidth transformer - it will be needed!
Place the compensation cap in parallel with the output resistor. Take care that ferrite-beads are present on all the susceptible nodes (anode, PNP base & collector), and that they are lower-frequency types - losses in the 500kHz-10MHz range are needed for these.
screen the feedback wire, and keep all of the circuit small.
Reviving an all thread after doing further experiments with this great driver:
6?5? Shunt Cascode Driver | Bartola Valves
Hope you find this useful
Cheers
Ale
6?5? Shunt Cascode Driver | Bartola Valves
Hope you find this useful
Cheers
Ale
Indeed. Well, I've been experimenting with different drivers as you know. Not needed for a 4P1L stage, but if you look at 300B, 814, 813, GM-70 and other transmitting valves, is key to get it right.
This is a long inactive thread, I think you can draw all of the conclusions needed from the fact that the last post was > 4 years ago.
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After ten years absense while doing other fun activities not involving electronics, I stumbled upon this thread and had to give it a go. This concept seems to work OK in the simmed world with parallelled 3A5 as driver, Had to spend half an evening brushing up LTSpice commandos.
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Hi Andy,
Just a small try to see if I still had some knowledge left. Went through the neglected electronic workshop, to sort out things as we a have bought a new house and found this stereo 6B4G PP chassis with wired cathode circuits and a handfull of 3A5´s, but without drivers. Next sim will be a PP version.
Just a small try to see if I still had some knowledge left. Went through the neglected electronic workshop, to sort out things as we a have bought a new house and found this stereo 6B4G PP chassis with wired cathode circuits and a handfull of 3A5´s, but without drivers. Next sim will be a PP version.
Thanks pl802!
Hadn´t given safety a thought
.
Can absolutely be built, but I would go for 6B4G with its lower heater current. Probaly needs some tweaking.
Senstivity is on the low side with just over 2V for 2W out.
Anyway, I pulled the 3A5 and got 105mA, 101V, 10,3W over the output tube, so it should cope. Also shorted the driver anode to ground and got 36mA, 350V, 12,5W.
https://shop.ehx.com/catalog/tubes-specs/6b4g-sovtek.pdf
https://soderquist.se/3A52A3choke.asc
Hadn´t given safety a thought
.Can absolutely be built, but I would go for 6B4G with its lower heater current. Probaly needs some tweaking.
Senstivity is on the low side with just over 2V for 2W out.
Anyway, I pulled the 3A5 and got 105mA, 101V, 10,3W over the output tube, so it should cope. Also shorted the driver anode to ground and got 36mA, 350V, 12,5W.
https://shop.ehx.com/catalog/tubes-specs/6b4g-sovtek.pdf
https://soderquist.se/3A52A3choke.asc
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Bad format, I can't open it either.My chromebook won't let me open that asc file
BTW, @revintage why not use DRD?
