I'm bringing 24 microphone lines to a Bantam patchbay, then out to 24
preamps. The studio getting this built wanted the system Full
Normalled.



I'm just wondering what to do with the shields at the patchbay. Should
they be carried through?

"nmm" wrote in message
oups.com...
I'm bringing 24 microphone lines to a Bantam patchbay, then out to 24
preamps. The studio getting this built wanted the system Full
Normalled.



I'm just wondering what to do with the shields at the patchbay. Should
they be carried through?

Yes, to maintain both shield and safety path
First, you must connect screen nearest to each preamp or mixer chnl i/p.
Good practice. Each screened cable takes its earth (ground) ref, assuming
the preamp hardware is itself permanently earthed to a good earth system,
from there...
for lowest noise, hum, cross-talk, and maximum human safety.

If contemplating using some pro capacitor mics, the common -ve or 0V from a
48V phantom power supply must merge at each preamp i/p jacksocket sleeve,
ie, normalled or eventually overpatched to any XLRs' pin1. Overpatching will
however double the screen source and 0V routes, unless you use patchcords of
the type where screen-is-terminated-only-one-end.
Make sure PSU is off when patching as damage to mics is alleged to occur,
besides generating 'orrible loud noises on speakers if faders are still open
So, note, if a mic route from stage box or studio wall box to its normalled
preamp is dissed by "overpatching", its screen will
still be earthed for safety.
Ensure 4th pole, the outer metal tab, on wandering mic female XLRs is also
linked to screen - as well as terminating pin1.
Make sure Bantam jacksockets are modern, ie having leaves plated with
palladium, not silver.
And of dire importance, what normalling pattern are you likely to use?
Inners to inners is best for mic default routes to avoid double- loading of
mics.

Jim

In article .com writes:

I'm bringing 24 microphone lines to a Bantam patchbay, then out to 24
preamps. The studio getting this built wanted the system Full
Normalled.

That's sensible, to avoid paralleling two preamp inputs on to a mic
when patching it to an alternate preamp. I'd caution them to turn
phantom power off when moving patch cables, however. Some mic preamp
inputs don't like to be "hot patched" and you can blow an input stage
that isn't properly protected.

I'm just wondering what to do with the shields at the patchbay. Should
they be carried through?

Yes, of course. You need shield continuity in order to carry phantom
power.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

Mike Rivers wrote:

In article .com writes:

I'm bringing 24 microphone lines to a Bantam patchbay, then out to 24
preamps. The studio getting this built wanted the system Full
Normalled.

That's sensible, to avoid paralleling two preamp inputs on to a mic
when patching it to an alternate preamp. I'd caution them to turn
phantom power off when moving patch cables, however. Some mic preamp
inputs don't like to be "hot patched" and you can blow an input stage
that isn't properly protected.

I'm just wondering what to do with the shields at the patchbay. Should
they be carried through?

Yes, of course. You need shield continuity in order to carry phantom
power.

I thought it was generally considered bad practice to have a mic
level patchbay. Shorting phantom power supplies, problems with
high resistance patch jacks and sockets as they age and so on.

--Dale

Dale Farmer wrote:

I thought it was generally considered bad practice to have a mic
level patchbay. Shorting phantom power supplies, problems with
high resistance patch jacks and sockets as they age and so on.

Using TTs or 1/4" bays for mike signals gives me the willies, for just
those reasons. But I know folks who do it... mostly folks with transformer
isolation on their console so the worst of the phantom issues aren't quite
so bad. I also notice that those folks are always having trouble with it,
too.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

In article writes:

I thought it was generally considered bad practice to have a mic
level patchbay. Shorting phantom power supplies, problems with
high resistance patch jacks and sockets as they age and so on.

Their mind is obviously made up - they're going to have a mic
patchbay. They might as well do it the best way they can. They have a
good start with the decision to use a patchbay with bantam (long
frame) jacks which are better for long term reliability. But it's one
more point of failure and one more thing that needs to be maintained.

It's not all that uncommon for large, multi-room facilities to have
tie lines between rooms that terminate in patchbays, and sometimes
they patch mics through those to record in a different studio than the
one normally attached to the control room. All it takes is doing the
job right and keeping the patchbay in good shape and it'll be OK.

But I wouldn't recommend using a $29 prewired 1/4" patchbay for mics
in a hobbyist studio. Better to build a panel of XLRs.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

"Scott Dorsey" wrote in message
...
Dale Farmer wrote:

I thought it was generally considered bad practice to have a mic
level patchbay. Shorting phantom power supplies, problems with
high resistance patch jacks and sockets as they age and so on.

You can't short Phantom PSUs as each +ve leg going to the mic interface
(programme pair) has a 6k8 series resistor which will current-limit the 48V,
should any short cct to 0V be made beyond it. But best to kill Phantom PSU
briefly when altering source away to another destin or vice-versa. In my
experience, jackfields plod on reliably for verily longer than the lives of
crap equipment housed alongside them!
or

Using TTs or 1/4" bays for mike signals gives me the willies, for just
those reasons. But I know folks who do it... mostly folks with
transformer
isolation on their console so the worst of the phantom issues aren't quite
so bad. I also notice that those folks are always having trouble with it,
too.
--scott

Flexibility, adaptability and modularity are the must-haves, fruits and
bonuses of pre-planning when it comes to running all default audio ins and
outs (at whatever point, Z or level) via normalled (&/or occasionally
patched) jackfields. The most perfectly designed mating connector pairs
shouldn't ever mate, in theory, because for example every XLR plug and XLR
socket have no tapered "wipe" characteristic, ie, every pin and its
receptacle are concentric or parallel but with the minute airgap of
clearance and sometimes oxidation!

And having as many audio-carrying holes as gear dictates is so much easier
and juser-friendly for cct testing or for substituting sources &/or destins.
Never skimp on size of your patchcord army! including specials to various
popular interfaces, pair-inverting and screen-tied-to-one-end types.

Don't worry, folks, about any good-quality normalled jacks and matching
gauge cords, that's their raison d'etre and their job!
Broadcasters who patch in real time would be at their wits' ends without the
forethought of flexible jackfields.

Jim

Mike Rivers wrote:
In article writes:

I thought it was generally considered bad practice to have a
mic
level patchbay. Shorting phantom power supplies, problems with
high resistance patch jacks and sockets as they age and so on.

Their mind is obviously made up - they're going to have a mic
patchbay. They might as well do it the best way they can. They have a
good start with the decision to use a patchbay with bantam (long
frame) jacks which are better for long term reliability. But it's one
more point of failure and one more thing that needs to be maintained.

It's not all that uncommon for large, multi-room facilities to have
tie lines between rooms that terminate in patchbays, and sometimes
they patch mics through those to record in a different studio than
the
one normally attached to the control room. All it takes is doing the
job right and keeping the patchbay in good shape and it'll be OK.

But I wouldn't recommend using a $29 prewired 1/4" patchbay for mics
in a hobbyist studio. Better to build a panel of XLRs.




Thanks for all the help, everyone.

I realised that the phantom power had to be carried through, but was
thinking with "Listen Point" patching as in the line level set up I'm
bringing both shields to the "A side" of the jackfields, I had no idea
what to do with the "Full Normal set up. They didn't want to run a Buss
wire and ground across everything, neither did I.

What i ended up doing was bringing each shield to it's respective jack,
and then running a short wire from the A to the B jack.

The set up is wiring straight to the back of the jacks; I'm used to
either having X-Mass Trees, or Punch Down/ Solder on Blocks. We are
using high quality bantam jackfields from Switchcraft.

"nmm" wrote in message
oups.com...

Mike Rivers wrote:
In article writes:

I thought it was generally considered bad practice to have a
mic
level patchbay. Shorting phantom power supplies, problems with
high resistance patch jacks and sockets as they age and so on.

Their mind is obviously made up - they're going to have a mic
patchbay. They might as well do it the best way they can. They have a
good start with the decision to use a patchbay with bantam (long
frame) jacks which are better for long term reliability. But it's one
more point of failure and one more thing that needs to be maintained.

It's not all that uncommon for large, multi-room facilities to have
tie lines between rooms that terminate in patchbays, and sometimes
they patch mics through those to record in a different studio than
the
one normally attached to the control room. All it takes is doing the
job right and keeping the patchbay in good shape and it'll be OK.

But I wouldn't recommend using a $29 prewired 1/4" patchbay for mics
in a hobbyist studio. Better to build a panel of XLRs.




Thanks for all the help, everyone.

I realised that the phantom power had to be carried through, but was
thinking with "Listen Point" patching as in the line level set up I'm
bringing both shields to the "A side" of the jackfields, I had no idea
what to do with the "Full Normal set up. They didn't want to run a Buss
wire and ground across everything, neither did I.

What i ended up doing was bringing each shield to it's respective jack,
and then running a short wire from the A to the B jack.

The set up is wiring straight to the back of the jacks; I'm used to
either having X-Mass Trees, or Punch Down/ Solder on Blocks. We are
using high quality bantam jackfields from Switchcraft.

Agreed, never buss the screens towards the mic source paths. As you are
familiar with IDC racks, use this super mode of distribution for permanent
wiring at line/domestic levels with your jack rows, both inners and outers
to blocks. Then you can drape default routes wherever u want.
But at mic level (can be around -60dBU), you must stick to local simple
normalling a-a and b-b links within the jackfield.

Hope u read my contrib two msgs back!
If you hard-wire sleeves A to sleeves B in a row, when u patch, say, i/p 3
from mic path 7, the latter will get the screen and Phantom PSU 0V from i/p3
as well as the screen and PSU 0V from i/p7. Could cause hum /noise in one of
those chnls if using different mic cable types and lengths to remainder.
Do u follow?
To avoid this, u should use the type of patchcord which has its screen
terminated at only one sleeve (3-pole wired to 2-pole at far end) and notice
and identify which end is earthed (grounded). If this type is not available,
modify a few standard 3-p to 3-p by lifting screen to sleeve connection at
one end.
Do not hesitate to ask me 4 more info.
Jim

Mike Rivers wrote:

Better to build a panel of XLRs.



On a metal panel? Would plastic work better?

Peter

In article . com writes:

Better to build a panel of XLRs.

On a metal panel? Would plastic work better?

It shouldn't make any differnce. Most panel mount XLR connectors don't
have pin 1 connected to the shell unless you put a jumber in the place
provided (if it's provided).

I suppose if you wanted to be fussy, a steel box (with steel panel)
would provide the best shielding.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

"Mike Rivers" wrote in message
news:znr1108255063k@trad...

In article . com
writes:

Better to build a panel of XLRs.

On a metal panel? Would plastic work better?

It shouldn't make any differnce. Most panel mount XLR connectors don't
have pin 1 connected to the shell unless you put a jumber in the place
provided (if it's provided).

I suppose if you wanted to be fussy, a steel box (with steel panel)
would provide the best shielding.

--
I'm really Mike Rivers )

Yes, plastic, steel, or ali case - but bond metal housing and its skt Shell
tabs (if using plastic panel) to a good earth (ground) nearby only for
reasons of SAFETY.
Listen he Do NOT connect metal panel skt Shell tab to Screen pin1, except
you should do at the cable skt at microphone end..
Apart from traditional metal mouldings, quite a few Neutrik XLR panel mounts
are made from plastic and some even have a shell "wiper" conn.
Jim

Mike Rivers wrote:

In article . com writes:

Better to build a panel of XLRs.

On a metal panel? Would plastic work better?

It shouldn't make any differnce. Most panel mount XLR connectors don't
have pin 1 connected to the shell unless you put a jumber in the place
provided (if it's provided).

I suppose if you wanted to be fussy, a steel box (with steel panel)
would provide the best shielding.

This is the best way. But, don't forget, you won't be able to normal it.
This means you will have to have 24 XLR patch cables in place.

Rob R.

Rob Reedijk wrote:
Mike Rivers wrote:


In article . com writes:


Better to build a panel of XLRs.


On a metal panel? Would plastic work better?


It shouldn't make any differnce. Most panel mount XLR connectors don't
have pin 1 connected to the shell unless you put a jumber in the place
provided (if it's provided).


I suppose if you wanted to be fussy, a steel box (with steel panel)
would provide the best shielding.


This is the best way. But, don't forget, you won't be able to normal it.
This means you will have to have 24 XLR patch cables in place.


Or include DPST normalling switches.

I suppose if you wanted to be fussy, a steel box (with steel panel)
would provide the best shielding.


This is the best way. But, don't forget, you won't be able to normal it.
This means you will have to have 24 XLR patch cables in place.


Or include DPST normalling switches.

Those switches would only cater for normalling each complementary pair of
male and female XLRs.
What if you need to divert chnl to another Source or mic to another Destin?
Just use coloured XLR jumpercords whose cord is 10% longer than distance of
the two XLRs furthest from one another, giving complete juggling flexibility
and obvious visual of your mic-to-chnl routeing, just like an old phone
switchboard. As I've said before, connect Shell to pin 1 screen only at the
roving, female mic end.
Jim

In article writes:

This is the best way. But, don't forget, you won't be able to normal it.
This means you will have to have 24 XLR patch cables in place.

Tough toenails.

Life is so complicated now that we have a choice of mic preamps. Used
to be that a snake going from the console's mic inputs to the studio
was all you needed. You can still do that with a rack full of preamps.
It just means that you may need more channels of snake than you'll
ever use in any one session. But you almost always have more paths on
a patchbay than you'll use in any situation.

Compare the price of an extra 16 channels of snake and stage box with
the cost of a high quality patch bay and you might find that simpler
is worth while.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo