Bride of ZEN zener diodes - diyAudio
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Old 28th May 2001, 01:39 AM   #1
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Does anybody know what wattage zener diodes are required for this circuit. I would suspect they are 1 watt items but I'm not sure.

Cheers

Dan
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Old 28th May 2001, 01:42 AM   #2
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Default Zen Zeners

Think it's 500mW. 1 watt wouldn't hurt.
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Old 28th May 2001, 03:06 AM   #3
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Vince,

is that for both the 10V regulator zeners and the 20V gate protection zeners?

Dan
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Old 28th May 2001, 04:04 AM   #4
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Dan,
1/2W (500mW) will do fine in both places. There's plenty of leeway. The Zeners in the regulator are only running at about 5mA or so.

Grey
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Old 29th May 2001, 01:27 AM   #5
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Yes, that for both 10v & 20v zeners.
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Old 29th May 2001, 03:14 AM   #6
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1/2 Watters it is then. One more question.
What VA transformer is required for 2 channels? Nelson does not specify in his article. Sorry for all the simple questions, they'll finish soon, I promise.

Dan
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Old 29th May 2001, 04:10 AM   #7
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Dan,
The Avel-Lindberg part that Nelson specifies is a 30VA transformer--30+30V @ .5A--fairly small.

Grey
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Old 27th November 2001, 02:55 AM   #8
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Default BOZ Transformer

The sound stage of BOZ is greatly enhanced, as are all the other good qualitys of the preamp, if you use an oversized transformer.
It draws a constant 40 ma. per channel or so, so it shouldn't make a difference if you use a 500 ma. or a 3 amp transformer, but it surely does in mine.
I tried it both ways, and the difference is NOT SUBTLE.
It makes a wonderfull improvement going from a 30va to a 180-230 va Avel Lindburgh transformer.
Fast/soft recovery diodes seem to help also when used in place of the specified rectifiers in the p.s. section.
mg16
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Old 27th November 2001, 03:04 AM   #9
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mg16,

I am using a 300VA 25-0-25 trannie at the moment and I must agree the sound excellent. My next project is the BSOZ as it has been mentioned on this forum time and again that it is supperior to the BOZ. I intend to use an oversized transformer on this one as well. I have not used fast diodes but they must be worth a try since they are only a few cents more than ordianry diodes.

Dan
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Old 27th November 2001, 03:39 AM   #10
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Dan,
We...and by we, I mean a lot of people from 'round these parts...never came to a conclusive, all-encompassing, definitive conclusion on audibility of fast vs. slow diodes. Never even managed to draw battle lines and take sides, for that matter. Go look for a thread about it about two or three months back. Got a good running start, tilted at the windmill...and decided not to decide.
All of which to be construed as a long-winded way of saying that no one really was able to say for sure whether fast/soft/slow/whatever diodes actually sound better.
I've used them on some projects & not on others. But, and here's the rub, I've never built a circuit, listened, then pulled out diode X and put in diode Y, then listened again. Nor had anyone else, at least as of the time of the thread. I believe Geoff had swapped diodes in a circuit, then later swapped them back, but ended up confused as to whether he had actually heard an improvement either way. There are theoretical arguments both pro & con, but little in the way of actual listening to lend creedence to either school of thought.
If you've got time, and an extra dollar, please do try both and report back. I, for one, would be interested in the results.

Grey
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