Groner Triple

[dadod]

Some time ago I noticed comments on D.Self book from Samuel Groner.
The part I would like to show now was about Triple output stage.

http://www.sg-acoustics.ch/analogue_...n_comments.pdf
It was this part of explanation that intrigued me to simulate an amp with this triple, but with bootstrapped CCS.

Depending on saturation characteristics of I2 and I3 this configuration
will yeld higher output swing compared to other triplr output stages.
For best efficiency these current sources could be replaced with bootstrapped
resistor loads, although this might result in somewhat reduced bias stability
with unregulated power supplies.

here is Groner triple as in his text.

[dadod]

Simulation result.

distortion 1kHz 0.000012%
distortion 10kHz 0.000086%
distortion 20kHz 0.000318%

I attached circuit diagram, FFT, OLG, CLG, square wave on 8ohm and 8ohm//2uF

I had to add C19 an C22. Without them square wave diagram had ringing and overshoots.
It did not influence Opel Loop Gain.
J3 and J4 are constant current sources.
dado

[lineup]

Originally Posted by dadod

Simulation result.

distortion 1kHz 0.000012%
distortion 10kHz 0.000086%
distortion 20kHz 0.000318%

How does this compare to for example one triple darlington output stage?
This is an output design I'd like to investigate.

[CBS240]

Looks like a double diamond buffer to me. A good circuit concept thats been around for quite a while. I like the bootstrap J-fet CCSs. J-fets make the best CCS don't you think?

[dadod]

Originally Posted by lineup

How does this compare to for example one triple darlington output stage?
This is an output design I'd like to investigate.

lineup,
It is very similar with triple EF. If you like to read more about this Groner triple follow the link I put in the first post.
What I did is just bootstrapp and FET CCS.
To know real difference soundwise it will be necessary to bild this amp.
dado

[dadod]

Originally Posted by CBS240

Looks like a double diamond buffer to me. A good circuit concept thats been around for quite a while. I like the bootstrap J-fet CCSs. J-fets make the best CCS don't you think?

In simulation I used 2N3819, but in real bild I would use Supertex DN3135 or DN2535 high voltage vertical deplation mode DMOS fets excellent for CCS. I could not find spice model(for LTspice) for this FET.
http://www.datasheetcatalog.org/data...x/DN3135NW.pdf
dado

[lineup]

Supertex has spice models for download:
Supertex - SPICE Models

[dimitri]

Phoenix Triple?

Rebirth of the Phoenix

[ostripper]

Yes , I am hours (or days) away from some sort of triple. Myself, B. Cordell, and many others discussed a similar type of circuit : Self type 3 EF (hybrid triple)... any pointers ??

I never got around to actually build it , but this now changes. I need a good sub amp . I have the PCB almost designed (below) and the cascoded luxman or blameless modules to hook to the triple. After seeing this groner/phoenix configuration , I feed "bold" with my couple square inches of PCB "real estate".
To have the required "overkill" , I will use ksa/c 1381/3503 , njw0281/0302 , njw21193-4 (pre/driver/main OP)
OS

[dimitri]

Awaiting your results