21 Dec
2011
21 Dec
'11
1:21 p.m.
On Tue, Dec 20, 2011 at 10:51:59PM -0500, gene heskett wrote:
Its been yonks, as in decades, and not in stereo, but
a locked oscillator,
and yes, even then I was surprised at the quality.
It's quite easy to do in SW these days. All you need is one of those
japanese boxes that were mentioned on this list (IIRC) a few days
ago. They provide downconverted I,Q. Input via you soundcard, add
a PLL, a few multiplies and some filters.
I'd consult with Bob Pease at National Semi., but
his penchant for driving
an old VW bug eventually wrote his obit about a year back.
I didn't know he died... He has certainly been a source of
inspiration for an entire generation of analog designers.
I still keep the old NS databooks he wrote...
One other instance comes to mind, one of my employees
had built an audio
board for the tv station, using 'raysistors' for the switching elements
ostensibly because the switching they could do was silent, unlike the
relays & switches of the day (1984). But at nominally +4dbm through them,
the intermod was pretty obvious. I pleaded for & bought a 12 + 4x a
channel input multiplier (48 in, 12 of them mics) board from Logitech that
used lamps & cds cells, much quieter intermod specs. But it was loaded
with enough 5532's that a cop of coffee sitting on it was nothing but 1/4"
of mud in the bottom in 2 hours. That heat killed the cds cells by the
grocery bag full. A couple 5" rotrons to suck out the hot air cut that
down to 1 or 2 a year, and some clip-on heat sinks helped the 5532's last
for years.
Hehe. For me one of the main advantages of digital audio gear is that
signals don't pass through zillions of switches, pots, etc. as it would
in e.g. an analog mixer. That alone makes a very big difference.
Ciao,
--
FA
Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl.