开云体育

I upploaded som photos of mics I've built. The most convinient place
for this was the "Photo"-section. Could we post all photos here?

iloccom wrote:

It would be nice if someone provided a design that uses the Panasonic WM-60AY correctly utilizing balanced XLR.

This requires some kind of differential amplifier or transformer.
ADI differential drivers are known to be quite good (SSM2142 for
example, www.analog.com).

Indrek

--
Indrek Rebane | Borthwick-Pignon
Electronics Engineer | Tartu Science Park
Phone: (+372) 7 302 641 | Riia 185, 51014 Tartu
Fax: (+372) 7 383 041 | Estonia
indrek@... | www.bps.co.ee

Rich Peet wrote:

Anybody know of any downside to having a seperation between the capsule and the electronics?

EMI shielding effect in capsule for noisy environments? FET inputs
are extremely sensitive.

Indrek

--
Indrek Rebane | Borthwick-Pignon
Electronics Engineer | Tartu Science Park
Phone: (+372) 7 302 641 | Riia 185, 51014 Tartu
Fax: (+372) 7 383 041 | Estonia
indrek@... | www.bps.co.ee

I recently ran across a microphone capsule that appears to keep its
fet a few inches outside of the capsule.

If there is no downside to that design I could see modifications of
the inexpensive capsules to have higher output and maybe less noise
with trial and error.

Also my RF condenser mics have all the electronics away from the
capsule as well, but that would be more expected.

Anybody know of any downside to having a seperation between the
capsule and the electronics?

Rich Peet

Mac suggests that I shouldn't even bother with posting from the
original group and making a mirror of those messages here.
It would save me time if we did make a clean break. Let me know if
anyone has strong feelings on that.

Any ideas as to how to move an archive to the files section or even
to copy all the messages would be good to know as well.

Rich Peet

--- In micbuilders@..., "Rich Peet" <richpeet@c...> wrote:

I have volunteered to moderate this new group.
It is a transition from

which was wounded by large quantities of spam.

I will hold an open period of "open membership"
This will close after a period of time and new members will be
reviewed.

I will post the daily digest of this group as often as I can which I
will expect to be at least 5 days per week. The daily digest will be
edited for spam. If anyone wishes to beat me to the daily digest
mirror post from this site that would be nice.

My intent is not to be a moderator of content or opionion as I am

not

saying or representing to be the most all knowing on this group. I

am

also as prone as anyone to an occational post that is not

appropriate.

If this new site takes off that is great. If it does not then we

will

decide after a period if this serves a function.

We will continue to search for a way to bring the archives and files
from the old group over to this one after "edit of spam" and will

look

into the way to do that.

Unless feedback is counter to my feelings I will not be reverse
posting new posts from this group to the old one.

This is a choice for all of you and you may decide which you prefer
to live and which to die.

I will start the mirror of daily digest tommorrow.

Rich Peet

Haven't been posting, but I have been keeping up with the group. Got a
couple projects in the works and I'll be sharing them soon.

i aagree we need the new group. so here i am

umashankar

i aagree we need the new group. so here i am

umashankar

I have volunteered to moderate this new group.
It is a transition from

which was wounded by large quantities of spam.

I will hold an open period of "open membership"
This will close after a period of time and new members will be
reviewed.

I will post the daily digest of this group as often as I can which I
will expect to be at least 5 days per week. The daily digest will be
edited for spam. If anyone wishes to beat me to the daily digest
mirror post from this site that would be nice.

My intent is not to be a moderator of content or opionion as I am not
saying or representing to be the most all knowing on this group. I am
also as prone as anyone to an occational post that is not appropriate.

If this new site takes off that is great. If it does not then we will
decide after a period if this serves a function.

We will continue to search for a way to bring the archives and files
from the old group over to this one after "edit of spam" and will look
into the way to do that.

Unless feedback is counter to my feelings I will not be reverse
posting new posts from this group to the old one.

This is a choice for all of you and you may decide which you prefer
to live and which to die.

I will start the mirror of daily digest tommorrow.

Rich Peet

Sanaka:

Why, though, is a 50V cap used? It seems the worst case you measured
was ~200mV. Couldn't the cap be a much smaller voltage rating?

No.

There was "~200mV" AC at this point without the capacitor.

You must differentiate between AC and DC conditions.

The DC voltage over this capacitor is 33.4 V DC in the original Schoeps
circuit when fed 48 V DC phantom voltage exactly.

This is very close to a nominally rated 35 volt capacitor and since one
cannot count with having all phantom voltage at exactly +48V, I have
seen from +24 to + 58 V over the years being called 48 volt phantom, so
some margin is needed to avoid shorting the capacitor as 35 volt is much
to close for comfort.

So at least 40 V makes sense as the electrolytic as specified in the
original Schoeps schematics is told to be 47F/40V.

Now depending on capacitor source maker we will either find a 40V or
more likely today 50V to what is available from many capacitor
manufacturers.

--
Best,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: mastering@...

Learn from the mistakes of others, you can never live long enough to
make them all yourself. - John Luther

Richard Lee:

What I meant was I doubt if the adjustment was for distortion.
It was simply to get DC conditions about right on different FETs.

Sorry no.

I have never ever seen any CMC 5 body not perfectly adjusted for minimum
K2, by adjusting P1, for minimum distortion.

BTW, passing by Schoeps home in Karlsruhe, Germany early March 1977
after having been to the AES 56th convention in Paris, France, to buy a
Schoeps CMC301 intensity stereo mic I was told directly by Jurg Wuttke
that P1 is to be adjusted for minimum distortion.

Sitting in his office I asked him about the sensitivity to humidity of
the capsules.

He then pushed a switch and increased the gain on a volume control and
it was possible to hear the outside traffic.

He then pointed to outside the window where a Schoeps CMC 5 body with
MK4 capsule was sitting out in the open and commented:

"It seems to be working still after 3 years out there."

--
Best,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: mastering@...

Learn from the mistakes of others, you can never live long enough to
make them all yourself. - John Luther