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Terry Pinnell
Guest
Tue Sep 20, 2011 9:29 am
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
--
Terry, East Grinstead, UK
John Tserkezis
Guest
Tue Sep 20, 2011 10:22 am
Terry Pinnell wrote:
Quote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
Short answer is it can't be done.
Longer answer: Firstly, you'll need a several microfarad capacitor in
series with the signal line to isolate it, otherwise the PC input
circuitry will try to feed it power. You might be able to get away
without it, but turns out that's the LEAST of your problems.
You'll serious amounts of gain. Your Dynamic mic outputs less signal
than a typical electret mic that would otherwise be used with a PC, so
even full blast, you'll *just* be able to hear it while yelling.
Certainly not viable, anyway.
Short of a pre-amplifier that's not going to happen, and since a
pre-amp isn't "Simplest" it can't be done to your requirements.
--
It's not the principle of the thing, it's the money
John Fields
Guest
Tue Sep 20, 2011 10:39 am
On Tue, 20 Sep 2011 10:29:05 +0100, Terry Pinnell
<terrypingm_at_DELETEgmail.com> wrote:
Quote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
---
Microphone transformer:
http://www.google.com/products/catalog?q=microphone+transformer&hl=en&prmd=imvns&bav=on.2,or.r_gc.r_pw.&biw=1280&bih=814&wrapid=tlif131651472395510&um=1&ie=UTF-8&tbm=shop&cid=8705588807110651835&sa=X&ei=qmt4TvyJJ6itsAKz-_StDQ&ved=0CJYBEPMCMAA#
--
JF
Phil Allison
Guest
Tue Sep 20, 2011 12:39 pm
"Globemaker"
The low impedance microphone needs a transformer to make it have high
impedance.
** Bad advice.
Mic inputs on PCs are not high impedance.
..... Phil
Globemaker
Guest
Tue Sep 20, 2011 2:14 pm
On Sep 20, 5:29 am, Terry Pinnell <terrypi...@DELETEgmail.com> wrote:
Quote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
--
Terry, East Grinstead, UK
The low impedance microphone needs a transformer to make it have high
impedance. Go to a guitar store and buy one for $20. It has 3 holes on
one end for XLR low Z and one the other end it has a 1/4 inch phone
jack like a guitar cord.
Terry Pinnell
Guest
Tue Sep 20, 2011 3:59 pm
Globemaker <alanfolmsbee_at_cabanova.com> wrote:
Quote:
On Sep 20, 5:29 am, Terry Pinnell <terrypi...@DELETEgmail.com> wrote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
--
Terry, East Grinstead, UK
The low impedance microphone needs a transformer to make it have high
impedance. Go to a guitar store and buy one for $20. It has 3 holes on
one end for XLR low Z and one the other end it has a 1/4 inch phone
jack like a guitar cord.
Thanks all. That inexpensive transformer looks ideal, but so far not found
a UK source.
I do have a few miscellaneous audio transformers, so in parallel with more
googling maybe I'll experiment. It'll get me away from the PC for a while
anyway ;-)
--
Terry, East Grinstead, UK
bw
Guest
Tue Sep 20, 2011 6:38 pm
"Terry Pinnell" <terrypingm_at_DELETEgmail.com> wrote in message
news:6tmg775oa5gsc39fhp6ar4t83l04akmfba_at_4ax.com...
Quote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
--
Terry, East Grinstead, UK
http://www.videotexsystems.com/product.php?productid=15798
bw
Guest
Tue Sep 20, 2011 7:00 pm
"Terry Pinnell" <terrypingm_at_DELETEgmail.com> wrote in message
news:6tmg775oa5gsc39fhp6ar4t83l04akmfba_at_4ax.com...
Quote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
Simple circuits for the casual audio electronics people
http://www.hobby-hour.com/electronics/computer_microphone.php
Terry Pinnell
Guest
Wed Sep 21, 2011 7:59 am
"bw" <bwegher_at_hotmail.com> wrote:
Quote:
"Terry Pinnell" <terrypingm_at_DELETEgmail.com> wrote in message
news:6tmg775oa5gsc39fhp6ar4t83l04akmfba_at_4ax.com...
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
Simple circuits for the casual audio electronics people
http://www.hobby-hour.com/electronics/computer_microphone.php
Thanks, useful article. May well get me back into my shed!
But as for
http://www.videotexsystems.com/product.php?productid=15798
at $100 (plus international delivery) I'll pass thanks ;-)
--
Terry, East Grinstead, UK
Tim Wescott
Guest
Wed Sep 21, 2011 4:56 pm
On Tue, 20 Sep 2011 10:29:05 +0100, Terry Pinnell wrote:
Quote:
In my shed I just came across a very old but apparently high quality
mic, a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It
proved useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
What _are_ the specs for a typical PC microphone input port? And are
there even specs, or does the circuit just happen to be what the
manufacturer felt like using at the time?
I gather that it's designed for electret microphones, then -- that makes
lots of sense. In theory that means that you could make a preamp that
would be powered by the PC, but that's only "simplest" if you have a well-
stocked junkbox, some knowledge, and some time.
--
www.wescottdesign.com
Terry Pinnell
Guest
Wed Sep 21, 2011 7:51 pm
Tim Wescott <tim_at_seemywebsite.com> wrote:
Quote:
On Tue, 20 Sep 2011 10:29:05 +0100, Terry Pinnell wrote:
In my shed I just came across a very old but apparently high quality
mic, a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It
proved useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
What _are_ the specs for a typical PC microphone input port? And are
there even specs, or does the circuit just happen to be what the
manufacturer felt like using at the time?
I gather that it's designed for electret microphones, then -- that makes
lots of sense. In theory that means that you could make a preamp that
would be powered by the PC, but that's only "simplest" if you have a well-
stocked junkbox, some knowledge, and some time.
Thanks Tim. I'm thinking about experimenting with that F-99B (seems a
shame to waste a fairly expensive mic) but it means cleaning up my shed
and workbench first - something I've been putting off for a couple of
years!
I have the first two of those requirements, but time is in short supply.
The circuits in the article referenced by bw up-thread are one starting
point, if I do make the initial effort.
http://www.hobby-hour.com/electronics/computer_microphone.php
I could even avoid the spring clean by doing some bread-boarding here at
my PC. ;-)
--
Terry, East Grinstead, UK
Rich Grise
Guest
Wed Sep 21, 2011 9:22 pm
Terry Pinnell wrote:
Quote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
I once had a mic like that so I slapped together a bog-basic common
emitter amplifier as a preamp.
http://www.electronics-tutorials.ws/amplifier/amp_2.html
(page 1 is all full of formulas and stuff - yech!)
Of course, for stereo you'd have to build two of them. ;-)
Have Fun!
Rich
Kaz Kylheku
Guest
Thu Sep 22, 2011 5:41 am
On 2011-09-20, Terry Pinnell <terrypingm_at_DELETEgmail.com> wrote:
Quote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
You have here a low impedance, dynamic mic, whose output is likely very
low. The mic socket expects a lot higher voltage signal, from a cheap,
high impedance microphone. The gain just isn't there.
Quote:
What's the simplest way of getting it to work on my PC please?
Get a (or, seeing what newsgroup this is, build yourself a) microphone
preamplifier. Because the impedance of the mic is low, you can get away
with a low input impedance, like 1000 ohms.
You can also boost the level passively with a transformer. A transformer
will also make the impedance of the mic input look lower to the mic. But
that's okay because the mic has low impedance, and is designed for a
low-ish impedance input.
This mic does not have balanced outputs. It is single-ended, and so it
will pick up noise. This limits the cable length you can use, even
though it is low impedance.
Kaz Kylheku
Guest
Thu Sep 22, 2011 5:42 am
On 2011-09-21, Rich Grise <richg_at_example.net.invalid> wrote:
Quote:
Terry Pinnell wrote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
What's the simplest way of getting it to work on my PC please?
I once had a mic like that so I slapped together a bog-basic common
emitter amplifier as a preamp.
For this you can do common base, too!
Terry Pinnell
Guest
Thu Sep 22, 2011 6:01 am
Kaz Kylheku <kaz_at_kylheku.com> wrote:
Quote:
On 2011-09-20, Terry Pinnell <terrypingm_at_DELETEgmail.com> wrote:
In my shed I just came across a very old but apparently high quality mic,
a Sony 'F-99B', 'One point stereo dynamic microphone IMP.LOW' It proved
useless when I tried it on my PC, in the usual mic socket.
My multimeter shows its left and right connections as about 170 ohms.
You have here a low impedance, dynamic mic, whose output is likely very
low. The mic socket expects a lot higher voltage signal, from a cheap,
high impedance microphone. The gain just isn't there.
What's the simplest way of getting it to work on my PC please?
Get a (or, seeing what newsgroup this is, build yourself a) microphone
preamplifier. Because the impedance of the mic is low, you can get away
with a low input impedance, like 1000 ohms.
You can also boost the level passively with a transformer. A transformer
will also make the impedance of the mic input look lower to the mic. But
that's okay because the mic has low impedance, and is designed for a
low-ish impedance input.
This mic does not have balanced outputs. It is single-ended, and so it
will pick up noise. This limits the cable length you can use, even
though it is low impedance.
Rich, Kaz: thanks both.
--
Terry, East Grinstead, UK
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