On Tue, 28 Aug 2007 19:38:08 +0100, "Keith G"
wrote:


"Keith G" wrote in message
.. .

"Laurence Payne" NOSPAMlpayne1ATdsl.pipex.com wrote


Is there a test recording somewhere that you two are keeping to
yourselves?



Nothing worth going *public* with!! ;-)

I'll post some music comparisons when I get it a bit better sorted...


Here's a couple of quick snatches which Swim *volunteered* while I had
the
mics set up as per:

http://www.apah69.dsl.pipex.com/show/Two%20Mics.JPG


- *not*, I hasten to add, anything like a proper setup for recording!

http://www.apah69.dsl.pipex.com/show...0&%20Valve.mp3

http://www.apah69.dsl.pipex.com/show...0&%20Valve.mp3


The left channel is the ribbon, the right channel is the valve mic -
each one conspires to make the other sound ****e...!!

:-)


Even on the clarinet they are chalk and cheese. I have to say the
ribbon wins it by a mile, though.

d

--
Pearce Consulting
http://www.pearce.uk.com

"Don Pearce" wrote in message
...
On Tue, 28 Aug 2007 19:38:08 +0100, "Keith G"
wrote:


The left channel is the ribbon, the right channel is the valve mic -
each one conspires to make the other sound ****e...!!

:-)


Even on the clarinet they are chalk and cheese. I have to say the
ribbon wins it by a mile, though.



They certainly seem to be opposite extremes! My feeling is that, at the
price, the valve mic is a worthwhile 'project' if not a truly
satisfactory 'finished item' - especially with all the accessories,
cables, flight case, shockmount, PS &c.

It will be an interesting challenge to see if it can be tidied up
nicely....

On Tue, 28 Aug 2007 20:07:18 +0100, "Keith G"
wrote:


"Don Pearce" wrote in message
...
On Tue, 28 Aug 2007 19:38:08 +0100, "Keith G"
wrote:


The left channel is the ribbon, the right channel is the valve mic -
each one conspires to make the other sound ****e...!!

:-)


Even on the clarinet they are chalk and cheese. I have to say the
ribbon wins it by a mile, though.



They certainly seem to be opposite extremes! My feeling is that, at the
price, the valve mic is a worthwhile 'project' if not a truly
satisfactory 'finished item' - especially with all the accessories,
cables, flight case, shockmount, PS &c.

It will be an interesting challenge to see if it can be tidied up
nicely....




Try this

http://81.174.169.10/odds/rib_valve_corr.mp3

Just a quick eq - pretty extreme, mind

d

--
Pearce Consulting
http://www.pearce.uk.com

It's now twenty years that I haven't been to China, so I don't know if the
culture against seperate inspection is still a factor, but since then I've
been sceptical of Chinese Quality Control ever since. There was a programme
on TV some weeks ago about a UK manufacturers that have factories in China,
and maintaining Quality seemed to recur as a problem. With modern automatic
pick&place machines and SMT, there is less scope for quality issues than
with hand soldered electronics, but nevertheless, if the culture doesn't
accept outside criticism, it doesn't bode well for quality.

S.



That "loss of face" issue is what caused a Korean airliner to be shot
down by the Russians some years ago;!...

--
Tony Sayer

In article ,
Don Pearce wrote:
It can be important when there is a wiring fault in the mic,
particularly with a ribbon mic, where it is possible to put phantom
across the ribbon and blast it out of the gap. If everything is OK,
though, there is never a problem putting phantom on a mic that doesn't
need it.

How do you get DC past its transformer?

With a ribbon the inrush current in the transformer is enough to do
the job. I've heard of permanently bent ribbons that way, although I
haven't seen it for myself.

The inrush current will surely be tiny given the correct standoff
resistors for phantom and the resistance of the primary winding? And the
ratio of the transformer would reduce it even more?

But maybe on shaky ground - if the transformer is balanced to ground
surely any inrush current would cancel anyway?

BBC TV used 4038s for audience reaction mics on permanently powered mic
inputs. For many a year. They may still do.

--
*I get enough exercise just pushing my luck.

Dave Plowman London SW
To e-mail, change noise into sound.

"Don Pearce" wrote


Try this

http://81.174.169.10/odds/rib_valve_corr.mp3

Just a quick eq - pretty extreme, mind


Much nicer! :-)

"Serge Auckland" wrote


It's now twenty years that I haven't been to China, so I don't know if
the culture against seperate inspection is still a factor, but since
then I've been sceptical of Chinese Quality Control ever since. There
was a programme on TV some weeks ago about a UK manufacturers that
have factories in China, and maintaining Quality seemed to recur as a
problem. With modern automatic pick&place machines and SMT, there is
less scope for quality issues than with hand soldered electronics, but
nevertheless, if the culture doesn't accept outside criticism, it
doesn't bode well for quality.


Serge, if we ignore 'audio' for a moment and think *computer*, I'd say
the Chinese were capable of some pretty fine PCB work. I remember
studying a network adaptor card (I think it was) a while back and being
blown away at the amount of tiny-sized components on it - and all for
about 7 quid! Whatever it was, it had a sticker on it: 'Designed in the
US, assembled in China' or summat very like it!

"Keith the Gormless Git "


** The Chinese do - wherever a via is really needed

12 year olds with bare feet, standing on a dirt floor in a big
galvanised
iron shed with a diesel gene droning on outside copying sample PCBs.

True enough - I suspect the 12 year olds are the ones approaching
retirement age, though.


I haven't been to China and I haven't seen for myself, but I
suspect/hope the views expressed above are not true or, if they are, I'm
pretty certain they won't last for long.


** He says - arguing foolishly from a position of self admitted
ignorance.


It's foolish to admit ignorance?


** Only utter fools ARGUE from a position of ignorance - their lack of
knowlege allowing them to hold any convenient opinion.



Wise up and ask someone who has really been there and seen the conditions
first hand - as I did.

Performing light assembly by hand in dirt floor sheds is nice work under
nice conditions, for rural China.


( snip drivel that backs ME up )



For the opposite - check out the Chinese factories making tubes for
compact fluorescent lamps, the ones we are now told are so efficient &
planet friendly we HAVE to use them, like it or not.

There is liquid mercury and its toxic compounds lying all over the
floors.


Don't make the mistake of thinking that sort of thing is exclusive to
China ..


** Don't make the mistake of thinking YOU are other that a

total F U C K W I T !!



....... Phil

"Phil Allison"

Wise up and ask someone who has really been there and seen the conditions
first hand - as I did.


** Before anyone asks me about my trip to China - the above should be read
as me speaking with someone who had done several " troubleshooting " trips
to rural ( galvanised shed ) factories.




...... Phil

On Tue, 28 Aug 2007 23:07:52 +0100, "Dave Plowman (News)"
wrote:

In article ,
Don Pearce wrote:
It can be important when there is a wiring fault in the mic,
particularly with a ribbon mic, where it is possible to put phantom
across the ribbon and blast it out of the gap. If everything is OK,
though, there is never a problem putting phantom on a mic that doesn't
need it.

How do you get DC past its transformer?

With a ribbon the inrush current in the transformer is enough to do
the job. I've heard of permanently bent ribbons that way, although I
haven't seen it for myself.

The inrush current will surely be tiny given the correct standoff
resistors for phantom and the resistance of the primary winding? And the
ratio of the transformer would reduce it even more?


The turns ratio of the transformer in a ribbon mic is extreme.
Apparently you can get enough current out to do the job. The
transformer increases the current (and reduces the voltage) towards
the ribbon.

But maybe on shaky ground - if the transformer is balanced to ground
surely any inrush current would cancel anyway?


Remember it is only when you have a wiring fault that this can happen.
That would be one side shorted to ground.

BBC TV used 4038s for audience reaction mics on permanently powered mic
inputs. For many a year. They may still do.

Very probably. The convenience would far outweigh the very slight
risk.

d

--
Pearce Consulting
http://www.pearce.uk.com