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Old 3rd May 2012, 05:21 PM   #5061
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Quote:
Originally Posted by SY View Post
If he doesn't, I do (that's the scope I use).
Our's are under an order of "do not repair". ISO rules make us have them repaired by the manu. and there's something like a $3000 min. (has to do with that "analog" stuff).
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Old 3rd May 2012, 05:24 PM   #5062
dvv is offline dvv  Serbia
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Originally Posted by jacco vermeulen View Post
...

Aren't we all.
Actually, I don't think I'm obssessed. My life is far too varied and colorful to allow for any obssession regarding anything, not time to be obssessed.

Not infrequently, obssessed also means possessed ...

Kudos on the kitchen utensils, though. Also my weak spot, I avoid shops selling the stuff because I know that if I go in, I'll be spending money.
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Old 3rd May 2012, 05:27 PM   #5063
dvv is offline dvv  Serbia
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Originally Posted by nigel pearson View Post
D V V brought up magnetic amps .

I wanted to get one made for a project at work . The usually obliging transformer manufacturer ran a mile . Anyone ever heard one ?

http://www.aes.org/aeshc/pdf/how.the...ndamentals.pdf
That's true, I did. For a split second there, I forgot the old programming line in Basic:

If magnetic and Nigel,
then Hawksford.

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Old 3rd May 2012, 05:28 PM   #5064
bcarso is offline bcarso  United States
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Perhaps germane regarding advanced degrees: http://www.nature.com/nature/journal...l/485041b.html
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Old 3rd May 2012, 05:29 PM   #5065
bcarso is offline bcarso  United States
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Quote:
Originally Posted by VladimirK View Post
At present, I find it grounded by practice to use only RF transistors at the output stage.
Such an approach sounds as a nonsense for those who designs for manufacturing companies, but among DIYers we concluded, that NFB designs definitely benefit from RF transistors at output stage, their sound comes close to that from NoNFB designs, with additional pluses remaining at the bottom end.
What do you consider to be "RF"?
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Old 3rd May 2012, 05:30 PM   #5066
bcarso is offline bcarso  United States
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Quote:
Originally Posted by scott wurcer View Post
Our's are under an order of "do not repair". ISO rules make us have them repaired by the manu. and there's something like a $3000 min. (has to do with that "analog" stuff).
How old of scopes does Tek still support?
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Old 3rd May 2012, 05:43 PM   #5067
dvv is offline dvv  Serbia
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Originally Posted by VladimirK View Post
dvv, thanks for your active position in this discussion, but, at analogy with one saying, "chair" designers will never find common position with "practice" designers. I belong to the last group, since for me it became obvious quite a long time ago - models are still very far from reality in the field of audio. Designing audio is much more tricky and less grounded by "theory" than designing instrumentation and control equipment.
Open Loop Bandwidth and quality of parts used (especially capacitors) are of the major importance. Hope the efforts of John Curl will bring something new upon the table.
If finding of proper parts really matters to you, I could try to send you some laterals, we have them supplied mainly from Singapore (almost sure not fake).
Thank you for your kind offer, Владимир, if push comes to shove, I may have to ask you for that favor, but it's too early to tell.

You see, my inital idea was to develop the amp primarily for my own self, but at the same time, to make it with parts which are not a problem to find, so that when I post it locally, local DIY people don't have to go around wondering how to get hold of some, to us, exotic parts.

I'm already over that line, having used BF 720/721, which not available locally, but my redeeming value is that Farnell has them on stock at all times, AND the Siemens version, which is the best of them all. Since most local suppliers work with Farnell, local ordering is possible.

I wonder, could you give a few examples of what you consider RF transistors suitable for audio power output use? Or did I get something criss-crossed?
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Old 3rd May 2012, 05:48 PM   #5068
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Quote:
Originally Posted by dvv View Post
That's true, I did. For a split second there, I forgot the old programming line in Basic:

If magnetic and Nigel,
then Hawksford.

That's as near a Knighthood as I will ever get . Thanks .

Nige
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Old 3rd May 2012, 06:04 PM   #5069
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Default A/B Tests

I was told that if during A/B comparisons A followed by A as a control , people heard the repeat as brighter . It was suggested that the ear / brain learns then listens more carefully hearing extra information . Has anyone a link to that ? If true it is important . This wasn't to trick people . Just to know if A/B is truly a test of comparisons . It shows a weakness in null tests if so .
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Old 3rd May 2012, 06:14 PM   #5070
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Quote:
Originally Posted by dvv View Post
AND the Siemens version
Unfortunately, Siemens hasn't done semi's in a dozen years, and Infineon does not manufacture them.
NXP still has the Philips BF720/721 versions on active duty, afaig.
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