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Old 2nd March 2004, 11:27 PM   #621
jam is offline jam  United States
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Default Waiting on ZV7..............

The Sound of One Hand

The master of Kennin temple was Mokurai, Silent Thunder. He had a little protege named Toyo who was only twelve years old. Toyo saw the older disciples visit the master's room each morning and evening to receive instruction in sanzen or personal guidance in which they were given koans to stop mind-wandering.

Toyo wished to do sanzen also.

"Wait a while," said Mokurai. "You are too young."

But the child insisted, so the teacher finally consented.

In the evening little Toyo went at the proper time to the threshold of Mokurai's sanzen room. He struck the gong to announce his presence, bowed respectfully three times outside the door, and went to sit before the master in respectful silence.

"You can hear the sound of two hands when they clap together," said Mokurai. "Now show me the sound of one hand."

Toyo bowed and went to his room to consider this problem. From his window he could hear the music of the geishas. "Ah, I have it!" he proclaimed.

The next evening, when his teacher asked him to illustrate the sound of one hand, Toyo began to play the music of the geishas.

"No, no," said Mokurai. "That will never do. That is not the sound of one hand. You've not got it at all."

Thinking that such music might interrupt, Toyo moved his abode to a quiet place. He meditated again. "What can the sound of one hand be?" He happened to hear some water dripping. "I have it," imagined Toyo.

When he next appeared before his teacher, Toyo imitated dripping water.

"What is that?" asked Mokurai. "That is the sound of dripping water, but not the sound of one hand. Try again."

In vain Toyo meditated to hear the sound of one hand. He heard the sighing of the wind. But the sound was rejected.

He heard the cry of an owl. This also was refused.

The sound of one hand was not the locusts.

For more than ten times Toyo visited Mokurai with different sounds. All were wrong. For almost a year he pondered what the sound of one hand might be.

At last little Toyo entered true meditation and transcended all sounds. "I could collect no more," he explained later, "so I reached the soundless sound."

Toyo had realized the sound of one hand.
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Old 2nd March 2004, 11:50 PM   #622
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Chateau Petrus is a Pomerol, which is in turn part of Bordeaux. Pomerols traditionally use the merlot grape. However, the rest of Bordeaux (Graves, Medoc, St. Emillion, et. al.) use blends--typically a backbone of cabernet sauvignon with cabernet franc and merlot being the two most common blending grapes. There are laws governing which grapes can be used in a Bordeaux wine. Seems to me there are about fifteen or twenty grapes that can legally be used, but that may be high; it may be as low as a dozen. That said, the two cabernets and merlot make up the lion's share of an average Bordeaux.

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Old 3rd March 2004, 05:05 AM   #623
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Do you always define the wine by the kind of grapefruit it's made from? (merlot, cabernet...)

This is very uncommon in France, especially for Bordeaux. The only wines we define this way are the wines from Alsace (where I live ). But they are white wines (like Riesling, Gewurtztraminer, Tokay...)

All the other wines are defined by the place where they are made (like St Emilion, St Estephe, Chateauneuf du Pape...)
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Old 3rd March 2004, 09:36 PM   #624
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Originally posted by Nelson Pass
My friend David Berkley, famous wine guy, keeps trying to
talk me into putting away the good years for appropriate
aging. Alas, no bottle of wine lasts more than a couple of
days in my house, so I have to keep the cases at work.

Buidling amplifiers + drinking all your wine the same day might
be called DIY not DUI. /hehe

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Old 3rd March 2004, 09:45 PM   #625
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Originally posted by paulb
I'm hoping I can fit a ZV7 (or earlier Zen) in here. Amp is a Technics SE-A5. Nice unit, but broken and deserves better guts.
In ZV7 I have managed to get the efficiency up on an SOZ type
circuit to about 16%, which I'm sure you will agree is a big
improvement on the previous editions (about 3%), and still using
passive loading. ZV8 is intended to improve on that with
active loading, but it's not going to get a whole lot better.

But looking at the heat sinks on your amp, I don't think this
will be the project for it.
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Old 3rd March 2004, 09:50 PM   #626
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There are two answers to your question.
One is that the French laws are quite restrictive as to what can go into a given wine. The Italians do much the same thing, incidentally. However, it's not obvious from the label. A Bordeaux label will have the name of the wine, but rarely will it spell out what went into it--all that is in the hands of the chateau.
The other is that here in the US, they are just now beginning to get serious about delimiting areas in the legal sense--particularly in California, e.g. Napa, Sonoma, et. al. However, within those areas there's no real restriction on which grapes you can use. The closest we come to restrictions in that area are percentages. If your label says that it's a cabernet sauvignon, it's got to contain at least X% of that varietal. Otherwise, you can do what you want.
Since grapes tend to have distinctive flavors, many if not most American vintners tend to bottle wines that are one varietal (predominately). That's not to say that there are no blends. In fact, there is a growing category called "Meritage" that is a conscious effort to emulate the Bordeau practice of using cabernet sauvignon, etc.
Part of the reason for all this anything-goes attitude is that we are still discovering what grapes work best over here. Zinfandel, for instance, does a dynamite job in California. The Italians know it as Primativo; I'm not aware that there's much of it in France. But CA Zins (not to be confused with Zens...) don't taste like anything else. Kinda like what the Australians have done with the shiraz grape (aka syrah).
I imagine that the wine scene here in the US will look very different in 100 years. By then people will have a better idea what works where and may have settled into the practice of blending...or maybe not. We'll just have to wait and see.

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Old 3rd March 2004, 10:33 PM   #627
moe29 is offline moe29  United States
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Mr. Pass,

Had you always planned to come back to the SOZ, for refinements?

Also, in the SOZ is the Absolute DC offset at either pole (+ or -)
aways the VGS of it's FET? Is that measurement adjustable in the
SOZ, to approzch 0V? (Like the resistors suggested my Ian McMillan
in the Aleh X thread) Or with this topology the reading doesn't
really matter - since the speaker will only see the difference
between the + and - posts.

hope i was clear in that qustion!

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Old 3rd March 2004, 11:06 PM   #628
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As long as you're only using one stage, the SOZ topology will always have some absolute DC offset. You can make it less by using bipolars or perhaps lateral MOSFETs, but it will always be there.

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Old 4th March 2004, 01:04 PM   #629
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So, ive started putting a Zen V5 together, designed a board as i find it easier to locate my errors that way and also nicer to keep tweaking with. Using the verry good Arcol HS resistors for R1 and R2, stable, tight tc, and easy to keep cool.
There is no mentioning of fuses in the rails, if one of the pots should go open the energy in half a farad would escape through
the mosfets right? Using a good Bourns cermet makes this risk minimal but... should there be fuses? Im a trial and error believer
and often ventute into error territory, but my wife dislikes flames from boxes in the livingroom.
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File Type: jpg zv5board.jpg (53.5 KB, 637 views)
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Old 4th March 2004, 07:21 PM   #630
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Originally posted by moe29
Had you always planned to come back to the SOZ, for refinements?
Also, in the SOZ is the Absolute DC offset at either pole (+ or -)
aways the VGS of it's FET
Probably ZV7-9 will still address the differential pair topology
(SOZ) and ZV10 will not.

The absolute DC voltage on SOZ and its variants is of no
prectical interest to the loudspeaker, only the differential.
We adjust the absolute figure only to optimize the power
or distortion numbers.
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