John Curl's Blowtorch preamplifier part II - Page 1799 - diyAudio
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Old 16th November 2011, 06:07 PM   #17981
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I have seen some of the old Telefunken, etc. master recorders. They were beautiful in mechanical design and construction.
Now, imagine this: Take a modern Studer transport, put all discrete electronics in it, phase compensated, Class A. Use the same width tracks and tape speed as the Germans did in WW2, but with modern tape and perhaps 5 times higher bias frequency. What do you get?
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Old 16th November 2011, 06:08 PM   #17982
jlsem is offline jlsem  United States
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The tapes had probably deteriorated quite a bit by the time they were transferred. I'm under the impression that some of the tapes were steel ribbon. A lot of that stuff was stored after the war in an Army warehouse in Cincinnati. I friend of mine acquired a Magnetophon machine from that facility (as well as a rocket motor from an Me 263!) and he said it was pretty awesome.

John
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Old 16th November 2011, 06:12 PM   #17983
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Quote:
Originally Posted by ThorstenL View Post
The old magnetic wire recordings could be edited in the same essential way as tape based on what I heard
Oh yeah, wire recorders! I had forgotten about them. (ask SY who invented the wire recorder). I've seen them "spliced" with a simple knot in the wire. It works.
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Old 16th November 2011, 06:19 PM   #17984
SY is offline SY  United States
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Quote:
Originally Posted by john curl View Post
Take a modern Studer transport, put all discrete electronics in it, phase compensated, Class A. Use the same width tracks and tape speed as the Germans did in WW2, but with modern tape and perhaps 5 times higher bias frequency. What do you get?
Something which works almost as well as a $600 Fostex recorder that's not based on stone knives and bearskins.
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Old 16th November 2011, 06:21 PM   #17985
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Thanks SY, for your input.
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Old 16th November 2011, 07:34 PM   #17986
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Well,

I got my speaker bracket shipped out today! Three more and everything will be on schedule.

Just got in an RCA 70 C-1 transcription turntable with some spare parts and the original manual!

Have to sim and expand on the series amplifier noise modulation issues latter.
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Old 16th November 2011, 07:38 PM   #17987
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Dick Sequerra prefers the Korg.
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Old 16th November 2011, 08:31 PM   #17988
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John,

Here are similar circuits but with low and almost matching values.
Attached Images
File Type: jpg Op Amp Noise Low R.JPG (42.2 KB, 150 views)
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Old 16th November 2011, 08:33 PM   #17989
anatech is offline anatech  Canada
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Oh man!
Having serviced Studer, Revox, Otari, Tascam, Fostex (horrible crap!), Scully, Ampex and MCI - I'm wondering why the question was even brought up?? Much of the earlier Studer was discrete. Thank god they got into IC's so they could EQ the head bumps out! Doing that the old way would have consumed ridiculous amounts of power.

Anyway John, all pre-IC electronics were "class A" until you got to power output stages. I'm pretty sure the industry had a great understanding of how to squeeze the last bit of performance out of a discrete circuit.

I've always wondered how good a machine Nakamichi would have produced had they gone after the open reel market though. Those guys really understood low noise signal amplification, perhaps more than people are generally aware.

-Chris
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Old 16th November 2011, 08:40 PM   #17990
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Originally Posted by anatech View Post
I've always wondered how good a machine Nakamichi would have produced had they gone after the open reel market though. Those guys really understood low noise signal amplification, perhaps more than people are generally aware.
They used a very elegant approach to *eliminate* ground contamination caused by the (series) power supply regulators too. And lots of Toshiba FETs!

Thanks,
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