[[email protected]]

Please, could anybody explain the following:
The signal from the condenser mic (MBHO 622 stereo, 200 ohm, 5 mV/Pa)
is fed into the DAV Electronics' Broadhurst Gardens preamp (150 ohm
input, unknown output) with maximum gain - 59 dB. The cables are
balanced Mogami 2549 (low Z). From the preamp the signal goes to the M-
Audio Delta 1010 D/A (10 kohm input) through the balanced Mogami 2552
cable.
The question:
Why do I get louder signal with the Signal Level Switch on the Delta D/
A set to the -10 dBV level, and not +4 dBu?
Do I have something wrong with the pin connections in XLR? I am
surprised why the preamp has to be turned all the way up in order to
get -3 dBF - on recording of such loud sound source as piano, with the
mic just 7 feet away.

Thanks
Alex

[Scott Dorsey]

wrote:
Please, could anybody explain the following:
The signal from the condenser mic (MBHO 622 stereo, 200 ohm, 5 mV/Pa)
is fed into the DAV Electronics' Broadhurst Gardens preamp (150 ohm
input, unknown output) with maximum gain - 59 dB. The cables are
balanced Mogami 2549 (low Z). From the preamp the signal goes to the M-
Audio Delta 1010 D/A (10 kohm input) through the balanced Mogami 2552
cable.

Okay.

The question:
Why do I get louder signal with the Signal Level Switch on the Delta D/
A set to the -10 dBV level, and not +4 dBu?

Read the manual. That's the reference level. It says that when your
level is at -10dBV, you get full scale, or when your level is at +4 dBu,
your level is at full scale. So the lower reference level means you have
more gain on the converter.

Do I have something wrong with the pin connections in XLR? I am
surprised why the preamp has to be turned all the way up in order to
get -3 dBF - on recording of such loud sound source as piano, with the
mic just 7 feet away.

Maybe. Maybe you have a cabling issue, maybe you have a phantom power
issue, maybe it's something else. How does it do with a generic dynamic
mike like an SM-57?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Laurence Payne[_2_]]

On Wed, 2 Apr 2008 14:24:18 -0700 (PDT), wrote:

Why do I get louder signal with the Signal Level Switch on the Delta D/
A set to the -10 dBV level, and not +4 dBu?

Because the -10 setting has higher sensitivity than the +4. The
figure refers to the signal level it expects to receive, not to the
amount of gain applied.

[[email protected]]

On Apr 2, 2:28*pm, (Scott Dorsey) wrote:


Read the manual. *That's the reference level. *It says that when your
level is at -10dBV, you get full scale, or when your level is at +4 dBu,
your level is at full scale. *So the lower reference level means you have
more gain on the converter.

Do you mean that the -10 dBV point represents the 0 dBF, after which
the clipping occur? And, respectively +4 dBu?


Do I have something wrong with the pin connections in XLR? I am
surprised why the preamp has to be turned all the way up in order to
get -3 dBF - on recording of such loud sound source as piano, with the
mic just 7 feet away.

Maybe. *Maybe you have a cabling issue, maybe you have a phantom power
issue, maybe it's something else. *How does it do with a generic dynamic
mike like an SM-57?
--scott

Thanks for the idea. But it seems that the phantom power is not to
blame: the pair of SM-57 in exactly the same setup and placement
delivers -13 dBF. About 10 dB lower than the condenser.
Does this mean, the wiring in the cable is wrong? Notorious pin 3?


--
"C'est un Nagra. *C'est suisse, et tres, tres precis."

[Arny Krueger]

wrote in message


On Apr 2, 2:28 pm, (Scott Dorsey) wrote:

Read the manual. That's the reference level. It says
that when your level is at -10dBV, you get full scale,
or when your level is at +4 dBu, your level is at full
scale. So the lower reference level means you have more
gain on the converter.

Do you mean that the -10 dBV point represents the 0 dBF,
after which the clipping occur? And, respectively +4 dBu?

Could be, or it could be that there is a certain amount of headroom above
the reference level. I seem to recall that the 1010 has 6 dB or so headroom.
The headroom would be the same in both cases since it is very rare for
headroom to differ for the same audio interface, just because you changed
the sensitivity.

The point is the difference between -10 and +4, which is not BTW 14 dB. In
actuality it is more like 11 dB because the reference points for -10 and +4
are themselves different.

The one thing that we can say for sure is that given the same amount of
headroom, a -10 input is about 11 dB more sensitive than a +4 input. And
that is the answer to the question posted in the OP.

Also, how are you estimating the signal level in your DAW files? I find
that its easy to underestimate the peak levels with a lot of software. The
software I use has an analysis feature that gives precise numbers for peak
levels.

Do I have something wrong with the pin connections in
XLR? I am surprised why the preamp has to be turned all
the way up in order to get -3 dBF - on recording of
such loud sound source as piano, with the mic just 7 feet away.

Here are the relevant questions, some of which you answered in the OP:

How loud is the piano being played?

I have seen the same notes in the same song on the same piano played in the
same context with acostic intensities that vary by about 30 dB.

More specifically, I've worked with a number different pianists at church.
One Elizabeth, plays very loudly. I haven't worked with her for several
years, but she used to play about 10 dB louder than Jan. Another pianist
Jan, used to play pretty loudly but has problems with arthritis, and seems
to have recently signficantly dropped the level she plays at. Becky used to
play softer than Jan, but since Jan dropped the levels she plays at, she is
now about 10 dB louder than Jan. Bratford plays at about the same level as
Becky. Since the songs being played are on a rotation, I've probably
experienced the same songs played for worship with all of them. I basically
look at the technical script and see who is playing piano today, and set the
mic preamp gain accordingly.

What is the room like? I could see a significant difference in level for
distant micing depending on whether the room is reverberent or very dry.

What is the sensitivity of the microphone? Common microphones have
sensitivities that themselves vary over an approximate 30 dB range. The mic
you are using has -44 dB sensititivty which is intermediate. It is much
more sensitive than a SM 57,

Which preamp? Common microphone preamps have sensitivites that vary over an
approximate 20 dB range. Your mic preamp has up to 59 dB sensitivity, which
is intermediate.

Maybe. Maybe you have a cabling issue, maybe you have a
phantom power issue, maybe it's something else. How does
it do with a generic dynamic mike like an SM-57?

Thanks for the idea. But it seems that the phantom power
is not to blame: the pair of SM-57 in exactly the same
setup and placement delivers -13 dBF. About 10 dB lower
than the condenser.

That is about what I'd expect.

Does this mean, the wiring in the cable is wrong?

Notorious pin 3?

Unlike condensor mics, most dynamic mics won't work at all unless there is
continuity on both pin 1 and pin 3. If you've lost continuity on either
pin, the phantom voltage will be reduced and with most condensor mics you'll
lose 6 dB worth of gain.

[Mike Rivers]

On Apr 2, 11:05 pm, wrote:

Do you mean that the -10 dBV point represents the 0 dBF, after which
the clipping occur? And, respectively +4 dBu?

Assuming that the controls are available, you can establish any
relationship between analog levels (dBu and dBV) and digital level
(dBFS) that you want, within the performance limits of the equipment.
But you don't always have those controls.

For example, if your mixer puts out +4 dBu when its meter reads 0 VU,
it can probably put out at least +20 or maybe as high as +24 dBu
before distortion sets in and the level can go no higher. If your
sound card has a fixed input sensitivity (as many do), it will
probably be called "+4 dBu." This means that when your mixer's meters
are reading 0, the record level will be somewhere in the ballpark of
-20 to -12 dBFS. Where it falls is the designer's choice and there's
no right or wrong.

What's wrong is that the designer didn't provide a control where you
can set it wherever you want so that you can make the headroom in the
mixer and the recorder match. But controls cost money and the
customers have spoken - they want to save money and most would be
confused by such a control anyway.

So what you got is what you get, or you learn how to set things up so
that meter readings are meaningful to you.

[Scott Dorsey]

wrote:
On Apr 2, 2:28=A0pm, (Scott Dorsey) wrote:

Read the manual. =A0That's the reference level. =A0It says that when your
level is at -10dBV, you get full scale, or when your level is at +4 dBu,
your level is at full scale. =A0So the lower reference level means you hav=
e
more gain on the converter.

Do you mean that the -10 dBV point represents the 0 dBF, after which
the clipping occur? And, respectively +4 dBu?

It's probably about 6 dB lower than 0 dBFS, really.

Do I have something wrong with the pin connections in XLR? I am
surprised why the preamp has to be turned all the way up in order to
get -3 dBF - on recording of such loud sound source as piano, with the
mic just 7 feet away.

Maybe. =A0Maybe you have a cabling issue, maybe you have a phantom power
issue, maybe it's something else. =A0How does it do with a generic dynamic=

mike like an SM-57?

Thanks for the idea. But it seems that the phantom power is not to
blame: the pair of SM-57 in exactly the same setup and placement
delivers -13 dBF. About 10 dB lower than the condenser.
Does this mean, the wiring in the cable is wrong? Notorious pin 3?

No, but check it with an ohmmeter and see. More likely you have something
in software set incorrectly. If you plug a pair of headphones into the
output of the preamp you should hear plenty of signal, too.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

Thanks, guys. With your explanations things make much more sense.



Do you mean that the -10 dBV point represents the 0 dBF, after which
the clipping occur? And, respectively +4 dBu?

It's probably about 6 dB lower than 0 dBFS, really.


Which means that I get even lower levels than I thought before.



No, but check it with an ohmmeter and see. *More likely you have something
in software set incorrectly. *If you plug a pair of headphones into the
output of the preamp you should hear plenty of signal, too.
--scott

Unfortunately, this preamp does not have the headphones input.
How exactly do I have to use the ohmmeter to test the potential
miswiring in the balanced connection?

If your sound card has a fixed input sensitivity (as many do), it will
probably be called "+4 dBu."

Does this mean that -10 dBV is not fixed because it uses voltage for
reference? And that is why +4 dBu is preferred - since it provides at
least some fixed reference, that is detectable by trial and error?

[Scott Dorsey]

wrote:
ng
in software set incorrectly. =A0If you plug a pair of headphones into the
output of the preamp you should hear plenty of signal, too.

Unfortunately, this preamp does not have the headphones input.

Who cares? Plug the headphones into the TRS output. Do you hear signal
at a reasonable level? If not, you have a problem at or before the preamp.
If so, it's afterward.

How exactly do I have to use the ohmmeter to test the potential
miswiring in the balanced connection?

Pin 1 should go to pin 1. Pin 2 should go to pin 2. Pin 3 should go to
pin 3. No two pins on either side should be connected together.

If your sound card has a fixed input sensitivity (as many do), it will
probably be called "+4 dBu."

Does this mean that -10 dBV is not fixed because it uses voltage for
reference? And that is why +4 dBu is preferred - since it provides at
least some fixed reference, that is detectable by trial and error?

No, he means if the input is not adjustable, it's probably fixed at +4.

You almost certainly have a software issue, but the headphones and the
ohmmeter will tell you the truth.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

On Apr 4, 3:37 pm, (Scott Dorsey) wrote:

Unfortunately, this preamp does not have the headphones input.

Who cares? Plug the headphones into the TRS output. Do you hear signal
at a reasonable level?

Most +4 dBu outputs will drive headphones OK, but just a couple of
warnings in advance:

1. If the TRS output is differential-balanced, the two earphones will
get signals of opposite polarity.

2. If the TRS output is balanced with one side being a resistor
instead of a signal, then one earphone will be dead.

[[email protected]]

Unfortunately, this preamp does not have the headphones input.

Who cares? *Plug the headphones into the TRS output. *Do you hearsignal
at a reasonablelevel? *If not, you have a problem at or before the preamp.
If so, it's afterward.


With the preamp at its max gain, the pianist playing as loud as
possible, and the mic 6 feet away, the headphones gave pleasantly loud
volume - nothing close to distortion, even on accents - which I find
strange.

Later today I will go and get the ohmmeter from RadioShack.

Alex

[Scott Dorsey]

In article ,
wrote:
Unfortunately, this preamp does not have the headphones input.

Who cares? =A0Plug the headphones into the TRS output. =A0Do you hearsigna=
l
at a reasonablelevel? =A0If not, you have a problem at or before the pream=
p.
If so, it's afterward.


With the preamp at its max gain, the pianist playing as loud as
possible, and the mic 6 feet away, the headphones gave pleasantly loud
volume - nothing close to distortion, even on accents - which I find
strange.

Why is that strange? That's how it should be.

Later today I will go and get the ohmmeter from RadioShack.

A flashlight bulb and a battery will do in a pinch, but you should have
a DVM sitting around anyway.

Almost certainly you will find it's a software problem.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Richard Crowley]

wrote ...
With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.

Why do you "find it strange"? Sounds like "normal" to us.

[Don Pearce]

On Sat, 5 Apr 2008 23:44:46 -0700, "Richard Crowley"
wrote:

wrote ...
With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.

Why do you "find it strange"? Sounds like "normal" to us.

Really? With a loud source and everything wound to maximum I would
expect severe overload - unless there was something wrong with the
system of course.

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

[Laurence Payne[_2_]]

On Sun, 06 Apr 2008 11:10:29 GMT, (Don Pearce)
wrote:

With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.

Why do you "find it strange"? Sounds like "normal" to us.

Really? With a loud source and everything wound to maximum I would
expect severe overload - unless there was something wrong with the
system of course.

Yeah. But a LOUD source is that mic stuffed inside the piano, or a
vocalist sucking and shouting into it. 6' back from a piano ain't
loud.

[Don Pearce]

On Sun, 06 Apr 2008 13:28:25 +0100, Laurence Payne
wrote:

On Sun, 06 Apr 2008 11:10:29 GMT, (Don Pearce)
wrote:

With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.

Why do you "find it strange"? Sounds like "normal" to us.

Really? With a loud source and everything wound to maximum I would
expect severe overload - unless there was something wrong with the
system of course.

Yeah. But a LOUD source is that mic stuffed inside the piano, or a
vocalist sucking and shouting into it. 6' back from a piano ain't
loud.

It certainly is. If I have a mic six feet back, with every gain knob
maxed out, I expect to be on the limit with a softly strummed acoustic
guitar. That is an awful lot of gain, you know.

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

[Don Pearce]

On Sun, 06 Apr 2008 13:28:25 +0100, Laurence Payne
wrote:

On Sun, 06 Apr 2008 11:10:29 GMT, (Don Pearce)
wrote:

With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.

Why do you "find it strange"? Sounds like "normal" to us.

Really? With a loud source and everything wound to maximum I would
expect severe overload - unless there was something wrong with the
system of course.

Yeah. But a LOUD source is that mic stuffed inside the piano, or a
vocalist sucking and shouting into it. 6' back from a piano ain't
loud.

Ok, here's what happens when you max out the gain controls. And this
isn't a loud source, just me talking. Most of the noise is a PC fan.

http://81.174.169.10/odds/maxed.mp3


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

[Richard Crowley]

"Don Pearce" wrote ...
"Richard Crowley" wrote:
wrote ...
With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.

Why do you "find it strange"? Sounds like "normal" to us.

Really? With a loud source and everything wound to maximum I would
expect severe overload - unless there was something wrong with the
system of course.

There are dozens of other pertinent details that are not disclosed
here.The symptoms are well within the range of "normal" IME.

[Ian Thompson-Bell]

Don Pearce wrote:
On Sun, 06 Apr 2008 13:28:25 +0100, Laurence Payne
wrote:

On Sun, 06 Apr 2008 11:10:29 GMT, (Don Pearce)
wrote:

With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.
Why do you "find it strange"? Sounds like "normal" to us.
Really? With a loud source and everything wound to maximum I would
expect severe overload - unless there was something wrong with the
system of course.
Yeah. But a LOUD source is that mic stuffed inside the piano, or a
vocalist sucking and shouting into it. 6' back from a piano ain't
loud.

Ok, here's what happens when you max out the gain controls. And this
isn't a loud source, just me talking. Most of the noise is a PC fan.

http://81.174.169.10/odds/maxed.mp3



But your system isn't the same as the OP is it? ISTR he said his pre had
59dB of gain. With the M Audio set to +4dBu nominal input level, M Audio
devices typically set 0dBFs to be 10dB higher or +14dBu so the input
level to clip is -45dBu. I would not expect a piano miced from 6ft to
reach this level.

Cheers

ian

[Richard Crowley]

"Scott Dorsey" wrote ...
Almost certainly you will find it's a software problem.

Or possibly the microphone itself. The MBNM 622 E PZ
apears to be a small "stereo" PZM microphone with a tiny
half- "Jecklin disc". If the OP is trying to use this lying on
an absorptive surface such as rug or carpet (or in mid-air)
the microphone may not be applied in the manner it needs
to produce the desired output levels.
http://www.mbho.de/pdf/mbnm621epz_mbnm622epz.pdf

Note also that we have heard nothing about the pad switch
on the preamp (26dB). Does the OP even know it is there,
or what a pad is?
http://www.davelectronics.com/bg1.htm

[Paul Stamler]

"Don Pearce" wrote in message
...
On Sun, 06 Apr 2008 13:28:25 +0100, Laurence Payne
wrote:

Really? With a loud source and everything wound to maximum I would
expect severe overload - unless there was something wrong with the
system of course.

Yeah. But a LOUD source is that mic stuffed inside the piano, or a
vocalist sucking and shouting into it. 6' back from a piano ain't
loud.

It certainly is. If I have a mic six feet back, with every gain knob
maxed out, I expect to be on the limit with a softly strummed acoustic
guitar. That is an awful lot of gain, you know.

Do we know what preamp and mic the OP is using? Max on his preamp may not be
all that max, and if it's a dynamic mic or a ribbon then 6' back may be nice
and comfortable level.

Peace,
Paul

[[email protected]]

On Apr 5, 11:44*pm, "Richard Crowley" wrote:
wrote ...

With the preamp at its max gain, the pianist playing as loud
as possible, and the mic 6 feet away, the headphones gave
pleasantly loud volume - nothing close to distortion, even on
accents - which I find strange.

Why do you "find it strange"? *Sounds like "normal" to us.

Because I used the cheap Sony Walkman headphones (not to regret if
they cook because of some anomaly in wiring - as Mike warned) - most
likely about 60 ohm into the XLR output of Broadhurst Gardens (it does
not have TRS out) - whatever impedance it is, I never could find a
figure. I would expect a preamp fully maxed on banging piano give at
least distortion on the occasional accents - through the 5mV/Pa
condenser.

Meanwhile, I got the $40 digital multimeter, and, just as Scott
suggested, the cables are good. The ohmmeter surprisingly (I do not
have any experience with electronic measurement) fluctuated in its
readings: from 0.4 to 125, changing about 3 times per second. I
googled for few hours, but could not find any explanations to such
weird behavior. There is no any calibration button at any rate. So, I
could not really find out if the resistance is under 2 ohm or above -
as the electricians advice for defining the open circuit. But I rang
the cables with the continuity test (apparently, it works at about 200
ohm), which showed perfect continuity from pin to pin, nothing cross-
connected.

Out of curiosity I rang the XLR pins on in and outputs of the preamp.
Only one pin was connected: left on the input to the right on the
output. Interesting enough, both channels had this single pin
interconnected.

Alex