77A's are so rare that I've yet to see one in person(and the couple I've seen sold have gone
$4-6K). I have done a number of 77-B's & C's, though, and I have to say that I think they
sound much better than the 77D/DX to me, for usually about the same money. Kind of halfway
between the D/DX sound & the big fat sound of a 44BX. The 77A/B/C are, indeed, completely
different animals than the D/DX. They are double ribbon mics, with the top ribbon section
being bipolar/velocity & the bottom section omni/pressure. The two sections are summed to
produce the cardioid pattern, or, in the 77-C, a switch selects between omni, bipolar or
cardioid by selecting either or both ribbon sections. The RCA KU-2 "Skunk mic" is also a
double ribbon, and is basically a 77-B in a different body. This is the traditional idea of
double ribbon design, as distinguished from the Beyer M130/M160, which simply have two ribbons
sandwiched together to get usable output from a small magnet structure. The 77D/DX is a single
ribbon, with a shutter plate on the back to vary backwave exposure for pattern control. The
only difference between a D & a DX is a stronger AlnicoV magnet on the DX, producing 2dB higher
rated output.
--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"David Curtis" wrote in message
om...
Moose wrote in message . ..
What do you think a fair price would
be for a fully functional 77A with a new cable and the original desk
stand?
I don't know about 'fair' but eBay is useful for calibrating current
market value. If you do an advanced search for "RCA 77" and check the
'completed items' box, you'll see matching auctions that completed in
the last month or so. Note that 'completed' doesn't mean 'sold' (might
be no bid, or reserve not met). I just did so and found the following
that actually sold in June:
A dropped/dented 77DX for $761
A 77DX in seemingly good shape with case/cable for $1527
Another 77DX in seemingly good shape with case/cable for $1326
A banged-up 77D for $655
Sorry, no As, but I suspect that they would run a little less than the
DX, even though they are rarer. DX seems to be the most sought-after
model for reasons discussed in other posts in this thread. I've seen
mint (or expertly refurbished) DXs go for $2k, $3K, and higher.
--Da5id