x soz

Re: Aleph x

stefanobilliani said:
Hi Stefano! I have simply look at the aleph x work done by Grey and transpose some parts in a soz front end a little bit modified . Sorry i cannot send any schematic . Also i have not any kind of measure . I 've just feel free to experiment!

Very useful post indeed ! Thanks for the informations, and I will try ASAP to cook mine using your recipe

Thanks again
Nelson Pass and diy .

Thank you mister Nelson Pass.But I have to tell , that day enthusiast took me over! And perhaps i'd need a language translator. I'm talking abouut sonic improvements on Son of zen. I don't know if the topology i use really (- or completly ) takes advantagies from supersimmetry ; but the concepts are there.No operational amps , 2 inputs 2 outputs.Improved stability and output dc offset nearly independent from small variatons of the bias resistors . Maybe only feedback effects ? And sound ... Not find the courage to retourn back to the basic version .Topology is :a soz ( without 1ohm resistor across source pins ) N channel output stage , a differential pair like aleph x ( except drain resistors values ) input stage and feedback from output stage (100Kohm resistor ) + resistor versus ground . I listen to this amp and music are very good and i find that lack of compressions that make the listener play records ... and play ...So at the moment i'm happy .Other <technical> thing are here to say Hope true.Thank you again.
hi Mr. Pass

Hallo, I'm Stefano from Italy, I want to ask you if the BZLS & SOZ are or not quite "supersimmetrical". I'm dreaming to build a BZLS + volume + newest Zen in balanced mode without output caps to use it like an integrated. Tank you for your experience.
Pass DIY Apprentice
Joined 2001
Paid Member
Maybe my post is the boring one. I'm the "experimetal design" guy. The circuit I'm working on isn't really an X ZEN - its more of a "two stage class a mosfet circlotron that has potential to be an X circuit" Right now I'm working on the "no overall feedback" version. My thought was to get it working well without gobal feedback, then try to apply super-symmetry. I'm having trouble with it at the moment, so maybe I should abandon it in favor of working up an X ZEN. I was really attached to the idea of an "X-CIRCLOTRON" the name alone sounds cool.


XZen is

OK, so since nobody else is jumping into this:

Take an X1000 input stage
Beef up all FET's with the usual Zen types
Lower voltages significantly
Increase current to required level (speaker impedance/power required, voltage ...
Omit output stage ....

You may go to the X100 reverse engineering thread to see schematics you can lift.

The one and only
Joined 2001
Paid Member

A cool name is half the attraction.

The Roger Corman approach:

First you think of a killer name

Then you draw up a really amazing poster

Then you shop is around for distribution

If you get enough distribution, then you make the movie

Please note that Roger Corman made a couple hundred
movies and only lost money on the one featuring
William Shatner.
X-Zen is...

Originally posted by Petter
Take an X1000 input stage
Beef up all FET's with the usual Zen types
Lower voltages significantly
Increase current to required level (speaker impedance/power required, voltage ...
Omit output stage ....

Assuming you are referring to the folded cascode diff pair (as in the Pass patent) - I am having difficulty squaring this with Nelson's hint:

Originally posted by Nelson Pass
You could explore creation of an X circuit with
a pair of inverting "current feedback" type chips,
if such a thing exists. These would have say a
gate for the negative input and a source for the
positive input. More to the point, you would have
a power inverter on the output stage of each.

Note particularly the mention of power inverter on the output stage. I don't think the folded cascode counts as an inverter, and last time I played around with this idea I couldn't see how to make use of the phase inversion. I ended up using a follower output stage but with the 'Aleph' active current source.

I also tried the circuit without an output stage but found that the gain was excessively effected by the load impedance. Maybe another "trick" is involved. I'll have to get my thinking cap on...