Zen-XA

[kristijan-k]

Hello,

Well, here is one another way. 🙂

Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

 

[kristijan-k]

The picture is too big, so it is little fuzzy.

Here is the link to the full size :
http://web.vip.hr/pcb-design.vip/zen-xa.html

 

[jh6you]

I believe you have already built it and had the sound test.
How was it?

JH

 

[jam]

It looks like a Zen-Aleph. Where is the X ?

Jam

 

[grataku]

It looks like a Zen-Aleph. Where is the X ?

Jam

That would be the 100K in series with the 220uF cap.

 

[jh6you]

Where is the X ?

I can not see any X. I see the balanced only.
The 100k and 220uF look like just a feedback.

JH

 

[Coulomb]

How does this design differ from your previous Balanced PZ4 design?

Anthony

 

[Peter Daniel]

I can not see any X. I see the balanced only.
The 100k and 220uF look like just a feedback.

JH

It is feedback from positive output to negative input, so it must be an X.😉

 

[jh6you]

It is feedback from positive output to negative input, so it must be an X.😉

Hi PETER!!

You might need one more cup of coffee. 😉
I meant no "secret" communication bridge between MOSFETs of port and starboard sides.

JH

 

[jam]

To be or not to be?

All I see is two seperate amps (Zen's with Aleph current sources).
To be an X I think the sources of the IRF9610's should be attached through a divider.( Or the power gain devices of each channel attached to ground through a resistor and the junction of the resistor and gain devices of both channels attached through another resistor)

Jam

 

[Nelson Pass]

Ah yes, you need for the current from the Sources of the
two stages to feed each other, and yours are going off to
ground.

No matter. This is easily fixed, and besides, it's a pretty
swell looking circuit already!


pass/ - not every amplifier has to be X

 

[Peter Daniel]

The drive from positive input should go to positive output, and on the schematic it goes to negative output. That's why the X is not visible, I guess.😉

 

[jh6you]

Your guessing is aligned with my guessing.

JH

 

[Henrik]

You still need a diffrential inputstage, otherwise you only have the ordinary NFB.
http://www.diyaudio.com/forums/showthread.php?postid=107410#post107410

 

[nobody special]

I agree with Henrik... you have to have the differential pair coupling to acheive the X feedback... otherwise it is only NFB.
Also, what is the point of building the circuit out of the zen? You have to add all the coupling capacitors. Isn't it better to have the Aleph split rails?

 

[kristijan-k]

Hello,

Thanks for the response.

The Zen-XA, like it's name say, is a combination of an ZEN-4 and
an X-Aleph amplifiers.

The Zen-XA is not very true X design in the current configuration.
If we make an X design, than the circuit would have little common with
the ZEN-4, and we again will get some sort of regular Aleph or X-Aleph.
Also, as we already have an Aleph-X, there is no point to make another
one, and as Mr.Pass said - not every amplifier has to be X 🙂

I used no split rails because I already had the transformer with the
single 25 V seccondary at the hand.

I tested the circuit and it is working great with the Balanced Line Stage.
It is also very quiet, the speakers are dead quiet.
The driving a 4 Ohm load is easy.
It sounds really good, but I can't tell more as I builted only one channel.
It seems that the bass is little tighter than on regular Zen-4.
After warm up, the offset is stable and it is easily adjusted.



Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

 

[BrianGT]

The Zen-XA is not very true X design in the current configuration.

Why don't you call it Zen-A then?

--
Brian