super symmetry seeking ideas

[hpt]

Hello all,

By means of an introduction, I should like to create an informative thread. I am an Electronics Engineering undergraduate studying with an emphasis towards audio electronics. I have chosen to do a final year design project involving ways in which to modify, vary or improve Nelson Pass' super-symmetry topology. The project will involve theory/mathematics, simulation and development. I still have a long journey ahead down the Audio path, as this field is certainly underrepresented within the electronics school at my (and other) universities. Please, if anybody would care to contribute ideas nudging me in possible directions of inquiry, I would be greatly appreciative. Whether this be suggesting shortcomings, room for improvement, or simply what is done great, I don't mind. Perhaps even a comment from Mr. Pass himself would be very encouraging!

At this point I am free to undertake anything I want, with any gain devices, providing it is relating to Mr Pass' original SUSY topology. I have been re-reading all of the Zen articles at this point also, and am interested in further exploring the potential of the SOX (zen variation 6). I will ask some more directed questions once I have more ideas and have had more time to ruminate over the Pass material. Perhaps a little high sensitivity speaker project will manifest from this also...

Regards,

Hayden

[Melon Head]

I would use the new SiC power jfets from semisouth. I bet you could ramble on for a couple of pages about those devices.
You could throw them into Aleph type circuit and convert it to an X circuit.
However I think it would be more interesting to build a circlotron circuit. I am not sure if you can apply the X factor to a circlotron, but I am sure other people will comment about that.

If you want to improve on the X circuit, I am not sure people will be willing to share that information freely. That is where you will have to do your own hard work. There is plenty of info here but it will take a while to get through it all.

Also look at this one
http://www.passdiy.com/pdf/zen-v7.pdf

[Nelson Pass]

If you haven't seen it, you might look at the GC supersymmetry
thread on this forum.

[hpt]

Thank you both for your advice. I will do some more reading up now.

Originally Posted by thanh1973

If you want to improve on the X circuit, I am not sure people will be willing to share that information freely. That is where you will have to do your own hard work. There is plenty of info here but it will take a while to get through it all.

That is agreeable; I wouldn't much enjoy the project without a lot of hard work ;-) I am merely trying to get an idea on the scope of what could be done and as I said, possible directions to begin looking into - I can't pretend that I am very competent at the design apects of amplifiers, but I am going head on into the learning.

hpt

[hpt]

Addendum: I meant no disrespect in assuming the possibility of improving upon the x-circuit. Now that I have done more thorough research, I realise the slim likelihood of this happening. Naturally, my project will involve attempting to apply the 'x-factor' in my own creative way.

At this point I am questioning the application of the symmetry topology to use with valves. Being suitable for single Class A stages, this seems reasonable, of course by nature of the symmetry circuit, none of the 2nd harmonic coloration of valves should be evident in the sound. So then there is no advantage in that regard. Keep in mind I haven't played with valves before so if there are any other technical reasons why it would not be suitable, then I do not know. I hope I have not offended anybodies solid-state sensibilities!

[hpt]

Silly me, of course it is the single-ended topology that promotes even harmonics, not the nature of the valves themselves... none-the-less, should be no coloration with this SUSY topology, therefore I see no reason to think about valves here except for nostalgia.

Would I be correct in assuming FETs are the device of choice for these high-power (ex. X1000) class A stages because of no bias current through the Gates? Or just because they are more robust?

...And how on earth do you edit your posts on this forum?

[Melon Head]

I think you have about 15 minutes to edit a post. Once the 15minutes has passed the edit option disappears.
Go buy yourself some power jfets.

[qusp]

I too would be keen on trying some semisouth power Jfets in a X'd circlotron, yes it can be done. search for Patrick's 2 stage power JFET circlotron. its a very novel type circuit, though not pass designed, its very pass like IMO, the X'd circlotron is not all that far removed from the X'd F5

[Nelson Pass]

I have one which is a JFET circlotron follower driven by
an X voltage stage which has a separate supply set.

Works great.

[Zen Mod]

Originally Posted by Nelson Pass

I have one which is a JFET circlotron follower driven by
an X voltage stage which has a separate supply set.

Works great.

surprisingly good also for sitting on it ?