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Topic: "Zaratustra II" to drive Macondo’s bass?

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Posted by Romy the Cat on 03-16-2007

I was yesterday drawing plans for the Zaratustra II’s chassis and was wondering how I might use it. The Zaratustra II turned out to be a little Monster, efforts-wise and expanses-wise. I hope it will demonstrate some results that will rectify the efforts and the expanses.

Anyhow, among any other thing that Zaratustra II will be testing there is a major quest that I have from this amp: will Zaratustra II be able to compete with Super Melquiades LF channel. This is very interesting to learn as I think it will be methodologically a relatively “frank” experiment.  Melquiades and Zaratustra in a way are similar amps: well, as closed as two-stages tube and two-stages hybrid could be….

In the Melquiades DSET the dedicated LF transformer that runs full power down to 7.5Hz, the low impedance of the 6C33C, a large reserve in the Melquiade’s LF power supply and the most important - the single-ended operation in A1 is the key that make bass so differently … different.

However, the Zaratustra II has own tricks in the sleeves:  up to 200W on class A1, it has good total current capacity (up to 60A stably and up to 90A in picks), it does not differentiates if it is 8R or 4R load – according to Dima’s tests – there was no measurable difference. Dima drove with Zaratustra II a load of 0.8Ohm and he claim that it was insultingly stable – the amp lost juts 20% of output but according to Dima nothing else changed in it. The Zaratustra II can drive 0.5R with no problems.  Furthermore, according to Dima nothing changed in the Zaratustra II when he drove with these amps a 8uF capacitor…  (BTW, did I mentions the Zaratustra II will be smaller then Lamm 1.1?)

So, would Zaratustra II be able to compete with Melquiades DSET driving the LF arrays of my Macondo? A DSET vs. high currant amp. SET dynamic vs. unlimited (for my room) power. Make your bets….

My bet is on Melquiades DSET – I do not think that it would be possible to over-perform a single ended amp if the amp has no transformer limitations. Yes, in my bet I am wiling to disregard the tremendous dumping capacity of Zaratustra II.  The only thing that I afraid off is that if Zaratustra II will perform more interesting then the Milq’s LF channel then… it might motivate me to go for 20H/.5A amorphous core for LF channel… At this point I do not want to think about it…

Posted by be on 03-16-2007
Hey!

Will you show some diagrams?
Could be interesting even if it turns out you dont like it.
20H/.5A amorphous? Who makes that?

Regards
be

Posted by Romy the Cat on 03-16-2007
 be wrote:
Will you show some diagrams?
Could be interesting even if it turns out you dont like it.
It is not my call. Zaratustra II’s circuit and some innovations that are being used in there are purely Dima’s creation and it is up to him how to use them.
 be wrote:
20H/.5A amorphous? Who makes that?
It is exactly what I would like DO NOT learn. To wind this transformer is not a big deal (it is juts LF) but to find this size core will cost fortune.

Posted by Paul S on 03-16-2007
If LF are sealed, I would suspect that the strong SS/hybrid would be better able to keep the drivers "off the air cushion".  When the drivers get to that point I hear something I would describe like this:  Take your fingernail and scratch the surface of the LF driver in question.  This sound, amplified, is what I hear as sealed drivers "load the air" in the sealed cabinet.  Not that other bass "solutions" do not have their own problems...

OTOH, SET seems to stay correct in terms of "vibrations", harmonics, and even impact, as far as it goes.  But it would take one hell of a transformer to overcome the SET "topological restrictions", even taking only extension into consideration.

Is Zarathustra Class A or A2 or A/B?  Or D...

Best regards,
Paul S

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