"Dave Plowman (News)" wrote in message
...
In article ,
Keith G wrote:

I'm tempted (that is to say planning) to add a 'multi-pattern tube
mic'
to my collection and, until just now, was mystified as to how a mic
like
this one:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWA:IT&ih=005


...could provide the various patterns (with in-between settings, it
appears) simply by fiddling with the power supply?? Anyway, a bit of
Googling has cleared this up (to a point) with information like
this...

http://www.tvtechnology.com/pages/s.0071/t.433.html

http://www.tonmeister.ca/main/textbook/node469.html

If you plot out the x and y axis of both an omni and figure of eight
then
add them together you'll see where a cardiod comes from. Indeed one of
the
first basic such types was the STC 4033 (guiness bottle) which was an
'apple and biscuit' moving coil omni (STC 4021) combined with a ribbon
(STC 4038) - the latter being a production version of the BBC PGS.


Now the questions a Is there any downside? Are there any reasons
to
avoid these 'dual/variable capsule' arrangements? (Especially at the
the
lower price point of these cheerfully cheep chinky chappies, or is it
like everything else from the Land Of The Noodle - if the basic
principle is sound, one takes one's chances, sucks it and sees...??)

The alternative is to stick to a straightforward cardioid design like
this one:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWA:IT&ih=005


Suggestions/caveats welcome....

Do you actually need a cardiod? All else being equal it's easier to
make a
decent omni. They also give less problems in usage. Of course if you
need
the separation in a multi mic setup or want to reduce room acoustics a
cardiod could well be the only way.

The capsule(s) is really what makes a condenser mic - the electronics
should be no problem in this day and age.
Oh - I forgot you like valves. ;-)



Well that was all very interesting Plowie, but I'm not sure what the
point of it was - my questions were specifically in respect of a
'multi-pattern tube mic' (as above)...??

Anyway, FWIW, I have made a grab for this one:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWN:IT&ih=011

- as it seemed to offer the features I want to try out and was (believe
it or not) a more appealing shape than some of the others!! :-)

(Far too many cheap valve mics to choose from on eBay atm!!)

At the price it won't be too much of a disaster if it turms out to be
poop (which I suspect it won't) - my concern has been/was that the
switching on the power supply to invoke the various patterns might be
shoddy and could only introduce noise &c. into the foodchain. We shall
see - I can only say that I have been very pleased with the Chinese mics
so far, so here's hoping!

Looking forward to some comparisons now (Chinese, Russian, valve, FET,
ribbon, various patterns &c.) - I'd post the results if I thought there
was a single soul here who could GAS...