I had a gig recording the Chicago Youth Symphony Orchestra last night.
This is Chicago's high-school and junior-high age orchestra, basically
training camp for the real deal.

I was going to bring an ADAT, a mixer, and a bunch of mics out to the
gig, but a pal of mine offered to loan me a portableTascam DA-P1 DAT
recorder with built in mic pres, so I said what the heck, let's see how
it goes with the mini-rig.

So I simply brought the Tascam, two mics, headphones, a mic stand and
cables. It all fit in a milk crate. Nice easy load in!

During the rehearsal, I tweaked mic placement, and then noticed that
the built-in limiter on the Tascam was switched on. I didn't want to
color the sound in any way (I was already leary of what the Tascam mic
pres might be doing to my sound), so I switched it off and reset my
level.

Through the rest of the rehearsal, I noticed that no matter how loud
the music got, the peak level never went above -3dB.

Watching the meters carefully, it certainly LOOKED like there was still
compression or limiting happening.

I dialed the input level all the way down to about "2" (yeah, pretty
arbitrary, I know, but hey, I didn't design the thing), and still
noticed that in the loudest passages, the unit still seemed to be
limiting at a threshold of -3dB.

Listening in my phones, I couldn't really hear the limiting effect, due
to my proximity to the real orchestra playing, and my phones not being
abe to reject enough of the outside sound.

Throughout the entire gig, the "margin" display never read above -3dB
(the margin tells you at what level your peaks are at).

Dumping the DAT into Digi Performer today, I could ABSOLUTELY see and
hear severe limiting on the recording. This was with the Limiter OFF.
I quadruple checked it - the limiter was definitely off. I can only
guess how brutally limited my dynamic range would have been with the
limiter on...?

Anyone have experience with this model of Tascam DA-P1 DAT recorder and
this extreme limiting at a threshold of -3dB with the Limiter off?

The parents of the students (the only people who will get the CD to be
presses from this recording) might not notice anything wrong with the
sound, but for future recordings, this unit is unacceptible. This is
really annoying - the recorder is more or less worthless.



JT

Did you have the pad switched on.... also you may want to use the pads in
your microphones. This unit is apparently designed for lower than normal
output microphones. If it's yours you may want to have a look at the
schematic and consider changing the gain of the mic pre.... I have a Sony
TCD-D10PII which suffers a similar problem.... in it the pad actually
changes a feedback resistor.... I changed mine to
-37db from the factory -20.... now works much better...

Rgds:
Eric
www.webermusic.com

"jt" wrote in message ...
I had a gig recording the Chicago Youth Symphony Orchestra last night.
This is Chicago's high-school and junior-high age orchestra, basically
training camp for the real deal.

I was going to bring an ADAT, a mixer, and a bunch of mics out to the
gig, but a pal of mine offered to loan me a portableTascam DA-P1 DAT
recorder with built in mic pres, so I said what the heck, let's see how
it goes with the mini-rig.

So I simply brought the Tascam, two mics, headphones, a mic stand and
cables. It all fit in a milk crate. Nice easy load in!

During the rehearsal, I tweaked mic placement, and then noticed that
the built-in limiter on the Tascam was switched on. I didn't want to
color the sound in any way (I was already leary of what the Tascam mic
pres might be doing to my sound), so I switched it off and reset my
level.

Through the rest of the rehearsal, I noticed that no matter how loud
the music got, the peak level never went above -3dB.

Watching the meters carefully, it certainly LOOKED like there was still
compression or limiting happening.

I dialed the input level all the way down to about "2" (yeah, pretty
arbitrary, I know, but hey, I didn't design the thing), and still
noticed that in the loudest passages, the unit still seemed to be
limiting at a threshold of -3dB.

Listening in my phones, I couldn't really hear the limiting effect, due
to my proximity to the real orchestra playing, and my phones not being
abe to reject enough of the outside sound.

Throughout the entire gig, the "margin" display never read above -3dB
(the margin tells you at what level your peaks are at).

Dumping the DAT into Digi Performer today, I could ABSOLUTELY see and
hear severe limiting on the recording. This was with the Limiter OFF.
I quadruple checked it - the limiter was definitely off. I can only
guess how brutally limited my dynamic range would have been with the
limiter on...?

Anyone have experience with this model of Tascam DA-P1 DAT recorder and
this extreme limiting at a threshold of -3dB with the Limiter off?

The parents of the students (the only people who will get the CD to be
presses from this recording) might not notice anything wrong with the
sound, but for future recordings, this unit is unacceptible. This is
really annoying - the recorder is more or less worthless.



JT

In Article , jt wrote:
I had a gig recording the Chicago Youth Symphony Orchestra last night.
This is Chicago's high-school and junior-high age orchestra, basically
training camp for the real deal.

I was going to bring an ADAT, a mixer, and a bunch of mics out to the
gig, but a pal of mine offered to loan me a portableTascam DA-P1 DAT
recorder with built in mic pres, so I said what the heck, let's see how
it goes with the mini-rig.
SNIP

Anyone have experience with this model of Tascam DA-P1 DAT recorder and
this extreme limiting at a threshold of -3dB with the Limiter off?

The parents of the students (the only people who will get the CD to be
presses from this recording) might not notice anything wrong with the
sound, but for future recordings, this unit is unacceptible. This is
really annoying - the recorder is more or less worthless.


Did they actually add a limiter to the DA-P1?
My experience was that, with loud sounds, you could clip the preamps without
seeing the meteres go off scale.

There was some little paragraph in the documentation that said something
like, ---If you're trying to record something really loud and have backed
the inputs way down (like around 2-3), you may be clipping the inputs.
Instead, put the pad on and increase the input sensitivity.

Maybe that's what you heard.

Regards,

Ty Ford

**Until the worm goes away, I have put "not" in front of my email address.
Please remove it if you want to email me directly.
For Ty Ford V/O demos, audio services and equipment reviews,
click on http://www.jagunet.com/~tford

Ty Ford wrote:

Did they actually add a limiter to the DA-P1?

The tale makes zero sense to me, a friend of mine has recorded live jazz
with DPA 4006's plugged into the mic inputs of this critter, but I am
not familiar with the recorders specific intricasies, and I am only
barely DA-P1 compatible and very happy if such a recorder actually
starts to record sound when I am to start it.

My experience was that, with loud sounds, you could clip
the preamps without seeing the meteres go off scale.

It is generally a good idea with this machine to use an external mic
pre, but it is handy to use the internal pre's and they just make it as
far as to "acceptable".

There was some little paragraph in the documentation that said something
like, ---If you're trying to record something really loud and have backed
the inputs way down (like around 2-3), you may be clipping the inputs.
Instead, put the pad on and increase the input sensitivity.

Input clipping makes most sense as the explanation of this to me. I
haven't got such a machine myself, so I can not verify this, but as I
recall some soundfiles somewhere on a harddisk it can record loud audio
from high output condensors without clipping or limiting in any way. If
need be then I can try to compare them with a parallel recording made
with an external pre and a SV3800.

Ty Ford


Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********

In Article , jt wrote:

Anyone have experience with this model of Tascam DA-P1 DAT recorder and
this extreme limiting at a threshold of -3dB with the Limiter off?

Not at all.

First make sure you aren't clipping the preamps, which is very easy to
do on that thing.

Secondly, try power cycling the thing and see if something has happened
to get the configuration stuck. Since the limiter is controlled by the
microcontroller in there, if the microcontroller gets confused I could
see something like that happening.

The parents of the students (the only people who will get the CD to be
presses from this recording) might not notice anything wrong with the
sound, but for future recordings, this unit is unacceptible. This is
really annoying - the recorder is more or less worthless.

I found the lack of input headroom a real issue and wound up buying a used
HHB instead when my DA P-20 finally became unrepairable. I don't regret it
for a minute.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"jt" wrote in message ...
So I simply brought the Tascam, two mics, headphones, a mic stand and
cables. It all fit in a milk crate. Nice easy load in!
snip
Through the rest of the rehearsal, I noticed that no matter how loud
the music got, the peak level never went above -3dB.
snip
Throughout the entire gig, the "margin" display never read above -3dB
(the margin tells you at what level your peaks are at).

Just checking, but did you reset the margin peak hold after switching off
the limiter?
--
Winter
www.EMBStudios.com
A World of Good Music
(510)325-1029

Could it be the top segment on the LCD meter isn't working?

Scott Fraser

jt wrote:

Anyone have experience with this model of Tascam DA-P1 DAT recorder and
this extreme limiting at a threshold of -3dB with the Limiter off?

Yes, this is a fairly well-known problem with the DA-P1's mic pres. They
clip very easily, with the limiter on or off. The DA-P1 pres are OK for
recording speech, but if your going for anything with a high SPL, I'd
use external pres with the line inputs or, better still, an external A/D
if you have it.

AT



The parents of the students (the only people who will get the CD to be
presses from this recording) might not notice anything wrong with the
sound, but for future recordings, this unit is unacceptible. This is
really annoying - the recorder is more or less worthless.



JT

In article ,
Artie Turner wrote:

jt wrote:

Anyone have experience with this model of Tascam DA-P1 DAT recorder and
this extreme limiting at a threshold of -3dB with the Limiter off?

Yes, this is a fairly well-known problem with the DA-P1's mic pres. They
clip very easily, with the limiter on or off. The DA-P1 pres are OK for
recording speech, but if your going for anything with a high SPL, I'd
use external pres with the line inputs or, better still, an external A/D
if you have it.

AT

Why not just use the built-in 20 dB pad?

-Jay
--
x------- Jay Kadis ------- x---- Jay's Attic Studio ------x
x Lecturer, Audio Engineer x Dexter Records x
x CCRMA, Stanford University x http://www.offbeats.com/ x
x-------- http://ccrma-www.stanford.edu/~jay/ ----------x

I have a DA-P1 and have no trouble putting it over -3db. Maybe the
limiter switch on the unit you used isn't working?

Jay Kadis wrote:

Why not just use the built-in 20 dB pad?

I've seen the pres clip on loud rock even with the pad engaged. The
limiter might be useful or capturing speech, but it's not very useful
for music at all. I was so disappointed with the DAP1 pres/limiter, I
quit "experimenting" on live recordings and used another front end.

I use the Millennia Media HV-3C's SPDIF out to the DA-P1 digital in with
great results.

AT

-Jay

Thanks for all the replies fellas.

I prefer not to use pads on comsumer/prosumer units when possible as
they sometimes color the sound.

All segments on the LCD are working; also the unit has a 'margin'
indicator telling you how much headroom you have left based on the
highest peak input since the 'reset' button was last pressed. This
number never wentt to -2, -1, or 0... always -3 or lower (I reset it
many times over the course of the show and rehearsal)

I definitely did the resetting of the margin indicator a bunch of times
AFTER disengaging the limiter. I disengaged the limiter about 1/4 of
the way through the rehearsal, and then recorded the rehearsal and the
actual concert without the limiter.

After disengaging the limiter, the evel jumped up signifigantly, and I
had to reset the input level fro about '6' to about '2.5'. So the
problem is not that the limiter was 'stuck on'.

I did not cycle the power after disengaging the limter; I guess I
should have.

Looking at the waveforms on the computer, the highest peak is
definitely -3dB. These peaks are also definitely very limited, it is
very very clear when viewing the waves. 'Flat-top hairdos' on all of
the loud parts.

I guess the comments about the mic pres overloading are my best answer,
that would explain a lot, everything, in fact, except why the limiter
threshold seemed to be set at --3dB WITH THE LIMITER OFF! And why
nothing went above that mark. COuld be a function of the mic pres, I
guess.

thanks

JT

In article , jt wrote:

I prefer not to use pads on comsumer/prosumer units when possible as
they sometimes color the sound.

That's a sign you got an impedance problem, or that you have a problem
with the preamp sounding different at different levels. That's a more
fundamental issue.

Looking at the waveforms on the computer, the highest peak is
definitely -3dB. These peaks are also definitely very limited, it is
very very clear when viewing the waves. 'Flat-top hairdos' on all of
the loud parts.

I guess the comments about the mic pres overloading are my best answer,
that would explain a lot, everything, in fact, except why the limiter
threshold seemed to be set at --3dB WITH THE LIMITER OFF! And why
nothing went above that mark. COuld be a function of the mic pres, I
guess.

Dunno, get out the bench oscillator and find out. Can you duplicate the
problem on the bench? If it's a mike preamp clipping problem, you should
have no problem duplicating it.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Looking at the waveforms on the computer, the highest peak is
definitely -3dB. These peaks are also definitely very limited, it is
very very clear when viewing the waves. 'Flat-top hairdos' on all of
the loud parts.

I guess the comments about the mic pres overloading are my best answer,
that would explain a lot, everything, in fact, except why the limiter
threshold seemed to be set at --3dB WITH THE LIMITER OFF! And why
nothing went above that mark. COuld be a function of the mic pres, I
guess.

Yes. This isn't limiting, it's clipping; the gain structure of the recorder is
set such that the clipping point of the preamp corresponds to -3dBFS. So first
you're sawing off the tops of the waveforms with the preamp, then making a very
accurate and non-limited recording of that sawed-off waveform.

Moral: Don't take a piece of gear you haven't wrung out thoroughly on an
important gig, at least not without also bringing along a complete backup.

Peace,
Paul

jt wrote:

I prefer not to use pads on comsumer/prosumer units when possible as
they sometimes color the sound.

If you put a line level signal into a mic pre - and you might well end
up doing that with high output condensers and a noisy event - then you
had better use the pads. If you do not, then you will clip the mic pre.

After disengaging the limiter, the evel jumped up signifigantly, and I
had to reset the input level fro about '6' to about '2.5'. So the
problem is not that the limiter was 'stuck on'.

If you are below "10 o'clock" on a mic input, then worry. As I recall
the DA-P1 "2.5" is around "9 o'clock".

I did not cycle the power after disengaging the limter; I guess I
should have.

You should have used the input attenuator. I need persuasion to believe
that it was the limiter that did not disengage, in fact you explanation
of the difference in input level setting required after disengaging it
shows that it DID disengage.

Looking at the waveforms on the computer, the highest peak is
definitely -3dB. These peaks are also definitely very limited, it is
very very clear when viewing the waves. 'Flat-top hairdos' on all of
the loud parts.

Flat tops = clipping, non = limiting, unless I have misunderstood those
terms.

I guess the comments about the mic pres overloading are my best answer,
that would explain a lot, everything, in fact, except why the limiter
threshold seemed to be set at --3dB WITH THE LIMITER OFF! And why
nothing went above that mark. COuld be a function of the mic pres, I
guess.

So it appears, but get knowledge: check this with a tonegenerator and a
voltmeter and/or scope.

thanks

Oh, don't worry ... I have goofed worse once upon a time, when I never
did grasp that the problem could be clipping and that I should have
moved those borrowed neumanns to the line input of the A77, it was very
clearly audible afterwards and caused it to be a waste of soprano and
organist's time. On location I thought it was monitoring that was
broken.

And then there was the time when I listened to the big band conductor
who complained over too much kickdrum and bass in the mix. Guess what
his complaint was afterwards ..... it had been right if I had
disregarded his comment on site.

Is the clipping audible? - if it is then it may or may not help to use
software with "unclip" capability, having such software I definitely
would try and experiment with perhaps some 2 to 4 dB peak recovery.

JT


Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********

Yes. This isn't limiting, it's clipping; the gain structure of the recorder is
set such that the clipping point of the preamp corresponds to -3dBFS. So first
you're sawing off the tops of the waveforms with the preamp, then making a
very
accurate and non-limited recording of that sawed-off waveform.

Yup, this is it.



Moral: Don't take a piece of gear you haven't wrung out thoroughly on an
important gig, at least not without also bringing along a complete backup.

Amen to that bro.

Who'd'a thought that clipping was happening when meters were reading
3dB of headroom? Not me. At least not until NOW!

JT

I prefer not to use pads on comsumer/prosumer units when possible as
they sometimes color the sound.

That's a sign you got an impedance problem, or that you have a problem
with the preamp sounding different at different levels. That's a more
fundamental issue.

This is probably a different discussion now; I find that many prosumer
or entry level preamps (ones built into less-than-pro consoles) are
audibly affected by engaging the pads. On analog boards, I'd rather
the level be **a little** hot than hit the pad. Obviously, there IS a
point, on some occasions, where I have no choice; where it is going to
clip noticeably and I MUST pad, but for me built-in pads on cheap
consoles are a last resort.

FWIW, the mics I was using at the gig in question at the start of this
thread don't have internal pads on them...

JT

I did not cycle the power after disengaging the limter; I guess I
should have.

You should have used the input attenuator. I need persuasion to believe
that it was the limiter that did not disengage, in fact you explanation
of the difference in input level setting required after disengaging it
shows that it DID disengage.

I agree; I never seriously considered that it didn't disengage, but
someone rasied the point so I addressed it.




Is the clipping audible? - if it is then it may or may not help to use
software with "unclip" capability, having such software I definitely
would try and experiment with perhaps some 2 to 4 dB peak recovery.



There is audible clipping on some of the crescendos and loudest parts.

What is this un-clipping software?

Plug-in?

I use ProTools and DigiPerformer on a Mac and also have some access to
a Sonic Solutions at one of the sutudios I work out of (StudioChicago
in Chicago).

The software - I am guessing - looks at the waves and then synthesizes
new peaks based on the intact portion of the waveform?

JT

jt wrote:

What is this un-clipping software?

Plug-in?

Comes with Audition, I don't know whether someone makes a DirectX plugin
with similar functionality. I had reasonable success with unclipping a
tambourine with it.

I use ProTools and DigiPerformer on a Mac and also have some access to
a Sonic Solutions at one of the sutudios I work out of (StudioChicago
in Chicago).

The software - I am guessing - looks at the waves and then synthesizes
new peaks based on the intact portion of the waveform?

I don't think I should stretch my technical ignorance further than
saying "yes" - it defaults to use splines to extend the flanks with, it
is not a recreation of "the real thing" but rather a credible version of
what it might have been. As for the applicability on the actual
recording: dunno.

JT


Kind regards

Peter Larsen


--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********

jt wrote:

I prefer not to use pads on comsumer/prosumer units when possible as
they sometimes color the sound.

If you don't know whether the pad on your recorder is usable or not,
that's something you need to test before your next recording. If a
pad is needed but you find that it colors the sound undesirably, then
you still need a solution to the problem of input overload, no?

At least equally important, you need to find out what signal levels
those inputs can accept without distortion, and note at what setting
of the recorder's input control the threshold of input overload is at
0 dB on the meters.

Say for example that I have a DAT recorder whose mike inputs clip at
100 mV. And say I observe that with the input level knob set at "3," an
input level of 100 mV produces a full scale digital signal on the meter.
If I take that recorder to a concert and find that I have to turn the
knob _below_ "3," then logically I know that my mike inputs are clipping,
regardless of any levels being shown on the meter or the lack of an
"OVER" indication anywhere.

In that example if a setting of "3" isn't low enough, then I absolutely
_must_ reduce the signals from the microphones somehow before feeding
them into the recorder's preamps. That could be done with resistive
pads in line at the mike inputs, or with some switch on the DAT recorder
(if I've tested it and it works well), or maybe even with both.

Is this logic fairly clear?

By the way, it's not at all unusual for the mike inputs of portable
recording equipment to be severely overloaded by the signals from
modern condenser microphones on loud music or even on music that isn't
super-loud. Borrow someone else's equipment for a live recording is a
crapshoot unless you've checked out its overload margins and other
operational details.

For extra credit, take the input overload level of the preamps and the
sensitivity rating of your microphones, and from that information you
can determine what sound level it takes for your microphones to clip
the preamps. If you know these limits, you'll be in a much better
position to decide what to bring to the next recording, such as in-line
pads that you trust sonically and/or outboard mike preamps, perhaps.


After disengaging the limiter, the level jumped up signifigantly,
and I had to reset the input level from about '6' to about '2.5'.
So the problem is not that the limiter was 'stuck on'.

Agreed. Unless something extremely unusual is happening, you can stop
even thinking about the limiter. The problem truly appears to be between
the microphones and the mike preamps in the recorder.


Looking at the waveforms on the computer, the highest peak is
definitely -3 dB. These peaks are also definitely very limited, it is
very very clear when viewing the waves. 'Flat-top hairdos' on all of
the loud parts.

Flat tops are _not_ the usual result of limiting, except for a truly
extreme type of super-fast limiting that's almost never used because
it sounds so bad. The usual type of limiting results in waveforms that
still have rounded peaks on steady tones--it's just that those peaks
are lower in level than they would be without the limiting in effect.

What you're describing isn't limiting, in other words; it's hard clipping.
You're lucky that it is apparently fairly clean clipping without ringing
or oscillation, which could be even worse.


I guess the comments about the mic pres overloading are my best answer,
that would explain a lot, everything, in fact, except why the limiter
threshold seemed to be set at --3dB WITH THE LIMITER OFF! And why
nothing went above that mark. COuld be a function of the mic pres, I
guess.

No need to guess--connect a signal generator to the microphone inputs,
set the record level control where you had it set, and observe that no
matter how high a voltage you pump into those preamps, the meters never
indicate anything higher than (in your case) -3 dB with the limiter off.

A mike preamp is generally a series of two or more amplifier "stages,"
each of which boosts the voltage and/or the current output by the previous
stage. Any overload within any stage of the preamp can only result in
a distorted (clipped) signal being transferred to the next stage for
further amplification.

That next stage does its thing as well as it can given that it's got a
distorted signal to work with--the best that it can do is deliver that
same distorted signal at a higher level of voltage and/or current, no?

The meters on the recorder are connected at a point in the circuit that's
well after the last stage of the mike preamps, since they are used for
line inputs as well as mike inputs. So they have no way to know whether
the first stage of the mike preamp was overloaded or whether you just
happen to be recording an acoustic signal that looks that way. Overload
in an early stage of the mike preamp will simply cause a distorted signal
to be presented on down the line and eventually measured by the meter
circuitry, which will duly report that its peak level is, in your case,
3 dB lower than the maximum which could have been recorded.

That's not a wrong reading; it's presumable a correct reading on a
distorted waveform. If the clipping hadn't occurred, of course, the
peak signal levels would have been considerably higher--but the fact is
that the clipping did occur, so they aren't.

Please forgive the degree of repetition in this message but I am hoping
that the essential points will be clearly communicated in the process.

--best regards

Here is the quote from my editing software on the function... suspect there
many other versions...

From the Sequoia manual

This option opens the declipping window, allowing you to destructivly repair
digital overs. This unique Sequoia function removes digital or analog
clipping. Sequoia uses high grade algorithms to interpolate the clipped
passages using the material that precedes/follows the clipped portion as a
reference point. Once processed, the total volume level for the material
can be further reduced to prevent any additional clipping. The declipping
algorithm is especially useful on material that contains obvious but no
heavily distorted clipping, such as piano or voice recording. It does,
however, have limits - heavily distorted material cannot generally be
repaired, although you may be able to significantly improve the dammaged
portion...

I have so far been fortunate and not needed to try it....

Rgds:
Eric

www.webermusic.com

"jt" wrote in message ...

I did not cycle the power after disengaging the limter; I guess I
should have.

You should have used the input attenuator. I need persuasion to believe
that it was the limiter that did not disengage, in fact you explanation
of the difference in input level setting required after disengaging it
shows that it DID disengage.

I agree; I never seriously considered that it didn't disengage, but
someone rasied the point so I addressed it.




Is the clipping audible? - if it is then it may or may not help to use
software with "unclip" capability, having such software I definitely
would try and experiment with perhaps some 2 to 4 dB peak recovery.



There is audible clipping on some of the crescendos and loudest parts.

What is this un-clipping software?

Plug-in?

I use ProTools and DigiPerformer on a Mac and also have some access to
a Sonic Solutions at one of the sutudios I work out of (StudioChicago
in Chicago).

The software - I am guessing - looks at the waves and then synthesizes
new peaks based on the intact portion of the waveform?

JT

This is a pretyy common topic on stealth-recording and DAT forums. You're
definitely clipping the preamps. The usual solutions are to pad the inputs
or just run the mics into the line-ins.

"Dave Latchaw" wrote in message


This is a pretty common topic on stealth-recording and DAT forums.
You're definitely clipping the preamps.

The usual solutions are to pad the inputs

A number of popular audio production specialty retailers including
Musician's Friend either don't sell mic attenuators or make them hard to
find. Type "attenuator" into the MF search engine and you get something for
guitar amps. Instead, Markertek gets my money.

However, there's a possible area of a concern with external attenuators.
Attenuators put resistors in series with the signal, which means that they
have resistors in series with the phantom power. A mic that draws the full
12 milliamps (6 milliamps per leg) could lose 6-8 volts or more of phantom
power through an inline attenuator.

or just run the mics into the line-ins.

Problem here is that condenser mics most likely source of large signals,
and they almost always require phantom power. I've never seen a line input
with phantom power. This means you have to line up an external phantom power
box. Back to Markertek!

Bottom line is that the *right* solution would probably be mic preamps with
built-in attenuators or enough dynamic range so that they can take +10
without clipping, just like a good line input.

In article writes:

Who'd'a thought that clipping was happening when meters were reading
3dB of headroom? Not me. At least not until NOW!

Actually it happens a lot, dating back to the Revox machines of the
'70s when mics weren't as sensitive as we're used to now, and we
didn't have as many of them so we tended to place fewer mics further
away from the source. The input stage had sufficient headroom to
accommodate those mics and techniques but didn't expect a couple of
hundred milivolts coming in, so metering was always beyond that point.

Even on consoles, often the only metering you have (if any) for the
input stage is a single overload light that comes on when you're close
to clipping that stage.




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In article group writes:

Yes, if you engage the -20db pad, which is almost
a necessity as you will get badly burned at some point if you don't,
the hiss goes way up and the crispness, presence, the depth of the
sound field etc. goes out the window but you do get a recording.

This seems to be the common perception with the DA-P1. Can anyone
explain why this is so? Is it a capacitive attenuator? Or does it hang
a low value resistor across the mic (drastically changing the loading
on the mic)? Still that wouldn't explain a change in the depth of
sound field "etc.".

If there's really something strange about the internal pad, perhaps
the simple and effective solution is to use an external in-line pad.



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Possibly it's like the Sony TCD-D10PII not a pad at all but a switch to
change feedback resistors.... which means it shouldnot have much effect on
the noise performance?? What's the big deal about changing surface mount
resistors other than the difficulty finding the in small quantaties...

Anyone have a schematic of the beast?

Rgds:
Eric

"Mike Rivers" wrote in message
news:znr1071315478k@trad...

In article group writes:

Yes, if you engage the -20db pad, which is almost
a necessity as you will get badly burned at some point if you don't,
the hiss goes way up and the crispness, presence, the depth of the
sound field etc. goes out the window but you do get a recording.

This seems to be the common perception with the DA-P1. Can anyone
explain why this is so? Is it a capacitive attenuator? Or does it hang
a low value resistor across the mic (drastically changing the loading
on the mic)? Still that wouldn't explain a change in the depth of
sound field "etc.".

If there's really something strange about the internal pad, perhaps
the simple and effective solution is to use an external in-line pad.



--
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

Don't use the 2 hour tapes.

Why? Unlike cassettes, a 2 hour DAT uses the same tape stock as a 30 min. DAT.
There's just more tape in the 120 shells, it's no thinner.


Scott Fraser

jt wrote:

FWIW, the mics I was using at the gig in question at the start of this
thread don't have internal pads on them...

It's just as well, unless the microphones themselves were in danger of
overloading. Nearly all switchable pads in condenser microphones are
designed solely to prevent the microphone's _own_ circuitry from being
overloaded by very loud sounds.

Now, the capsule of a modern condenser microphone is normally very hard
to overload; it's almost never the problem, except with some exotic or
"vintage" microphones that have ultra-thin, pure metal diaphragms. So
these pads operate at the input to the first amplifying device (FET or
tube) inside the microphone.

That approach has an unfortunate side effect: It reduces the signal-
to-noise ratio of the microphone considerably (since the main noise of
a microphone is generated within its first active stage).

So if the microphone itself is not being overloaded, such pads should
not be used to prevent the overloading of preamps/mixers/recorders
downstream. Instead, resistive pads should be used at the input of the
equipment to which the microphone is connected; they don't have the
aforementioned side effect.

Of course if you don't have resistive pads on hand [a] go get some
(even the good ones aren't expensive) but until you do, [b] you're
stuck using the pads in the microphones and getting a far noisier
signal than would have been necessary.

This is a basic lesson in audio engineering but it's one that many
engineers still need to learn, so don't worry--you're in good company.
In plenty of studios the pads are permanently set on all condenser
microphones because the engineers have never figured this out.

On some condenser microphones, notably Neumann FET80 series (KM-84, etc.) the
attenuator was a capacitor set up to provide feedback from the drain of the FET
to the base. Didn't hurt the signal-to-noise, but to my ears the distortion was
always worse on lower-level signals with the attenuator switched in than with
it switched out. In fact, my KM-84s NEVER sounded good with the attenuators in.
If I need to record something too hot for the unattenuated KM-84s, I pull out
another microphone.

Peace,
Paul

In article writes:

What's the big deal about changing surface mount
resistors other than the difficulty finding the in small quantaties...

Anyone have a schematic of the beast?

You've just identified the second difficulty. Sony used to be
pretty free (like, for free) with their service manuals for analog
recorders, but I don't know what the situation is with digital
equipment. Why not call the service or parts department and see if you
can order a manual.



--
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

In article writes:

Don't use the 2 hour tapes.

Why? Unlike cassettes, a 2 hour DAT uses the same tape stock as a 30 min. DAT.

He's probably thinking about 120 meter rather than minute tapes, which
are thinner (and run 4 hours).




--
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

In article znr1071336745k@trad, Mike Rivers wrote:
In article writes:

What's the big deal about changing surface mount
resistors other than the difficulty finding the in small quantaties...

Anyone have a schematic of the beast?

You've just identified the second difficulty. Sony used to be
pretty free (like, for free) with their service manuals for analog
recorders, but I don't know what the situation is with digital
equipment. Why not call the service or parts department and see if you
can order a manual.

Tascam has a service manual for about $20.

I don't have one, but I do have a service manual for my old DA P-20, and
it had a real resistive pad on the front end of the mike preamp, not just
a gadget that changed the feedback.
--scott

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

In article group writes:

I once
used the 2 hour Dats that were from the center of computer stock reels
or something for about a week. (MasterDat, from Cassette House). I got
subsequent error messages, the transport wouldn't work and the service
to correct the machine cost me $50 so I never used 2 hour Dats in
anything ever again.

Sounds like a coincidence to me. I've used hundreds of the Cassette
House MasterDAT 2 hour tapes with no problems. And $50 service on a
DAT recorder is a blessing. Be thankful that it didn't cost you $500.

DAT tape and recorders is funny. The whole arrangement depends on a
much higher level of precision than analog tape and the smallest
deviations can keep the best of systems from working. About the only
thing that's predictable is that thin (long data backup) tape is less
likely to work than tape of the standard audio thickness. For a while,
people were sending machines back to the factory for a tension
modification that allowed them to work with the thinner tapes, but
that made them less reliable with standard tape.

While I still use my DAT for convenience, I prefer not to depend on it
as my only recorder these days.

Someone asked about a schematic and I bet Eddie Celletti (sp?) has
one.

I'm sure he has the service manual, but he won't touch a DAT for less
than $450 these days. That's why my DA-P20 is sitting on the pile of
stuff that doesn't work but was too expensive to throw away. I really
should get in touch with TEAC and see if they'll still work on it.
Eddie doesn't want it to leave his shop without a complete going-over
which will no doubt involve replacing some capacitors, a full
alignment, and sprkinling with holy water. It sounds like the tape is
bouncing off the heads, so that could be a mechanical tension
adjustment, a worn mechanical part (not likely since it doesn't have
that many working hours on it), or a servo misadjusted or with a
failed component. Without a thorough diagnosis, which is not easy
because of the difficulty in taking the thing apart to get access to
test points and the transport, it's impossible to tell exactly what it
takes to get it working again.

If I could get it to
sound better for $200 I'd do it but otherwise I will wait for the Next

As long as it still moves tape, I'd look into a mic preamp that has a
digital output. I don't know of one I'd recommend that's $200 or less
though, and I don't think it's worth spending $500 on an external
upgraded front end.




--
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
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In Article , (Scott Dorsey)
wrote:
In article znr1071336745k@trad, Mike Rivers wrote:
In article
writes:

What's the big deal about changing surface mount
resistors other than the difficulty finding the in small quantaties...

Anyone have a schematic of the beast?

You've just identified the second difficulty. Sony used to be
pretty free (like, for free) with their service manuals for analog
recorders, but I don't know what the situation is with digital
equipment. Why not call the service or parts department and see if you
can order a manual.

Tascam has a service manual for about $20.

I don't have one, but I do have a service manual for my old DA P-20, and
it had a real resistive pad on the front end of the mike preamp, not just
a gadget that changed the feedback.
--scott


I lost the original poster on this, but having been in a VERY similar
situation with the DA-P1, I found that sources loud enough to cause the
record level to be backed off to 2-3 meant you HAD to use the on-baord pad.
The record levels would NOT show overs, but the recordings were obviously
clipped. It's in the manual.

Regards,

Ty Ford

**Until the worm goes away, I have put "not" in front of my email address.
Please remove it if you want to email me directly.
For Ty Ford V/O demos, audio services and equipment reviews,
click on http://www.jagunet.com/~tford

spud wrote:

Ah, the DA-P1. If you search your Dejanews archives you can
spend many sinking hours reviewing outraged laments of the
sorry preamps on this recorder.

So you say. Not checked.

No, you can't fix it up, it's all surface mount circuitry.

It is possible, but not easy, to solder on some smd boards.

Forget the meters; don't go over 4 on the rotaries and you will be ok.

Please explain the correlation with actual facts, it just does not make
sense to me.

It is of course possible that matters are different when using the mic
input, but when using the line input the meter reading corresponds
nicely with the actual audio data as I recall working with audiofiles
from a DA-P1.

Even if you were right, then it makes more sense to consider actual
signal level than to consider absolute rotary fader position.

Don't let the meters peg over -15 0r -12.

Why not, they track with the meters on my SV3800 when I feed a DA-P1 a
digital signal and indicate clip when it does it. And it isn't clipped
if it hasn't indicated that it was.


Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********

Paul Stamler wrote:

On some condenser microphones, notably Neumann FET80 series (KM-84,
etc.) the attenuator was a capacitor set up to provide feedback from
the drain of the FET to the base. Didn't hurt the signal-to-noise, but
to my ears the distortion was always worse on lower-level signals with
the attenuator switched in than with it switched out

I have a Neumann MA 84 test head for KM 84-type microphones, so I just
now checked the THD+N with and without the pad in place. With a 315 Hz
tone at about 75 mV, using a 100 Hz high-pass filter, the THD+N looked
about the same--about 0.040%--whether or not the microphone's pad was
switched in. This was measured via a Grace Lunatec V2 preamp at moderate
gain settings adjusted to compensate for the pad.

Unfortunately I can't make meaningful noise measurements at the moment
for lack of a miniature Lemo shorting plug. When I tried to short the
regular signal input cable that I have, it was evident that RFI or some
other stray signal was swamping the input noise.

The idea is, though, that even if the raw noise voltage of the microphone
is the same with or without the pad as you state, the signal voltage as
attenuated by 10 dB must be compared to that constant noise floor. So
about 10 dB signal-to-noise performance is being lost IF the microphone
could have been used without the pad.

Just as a reminder, signal-to-noise ratios for condenser microphones are
not a "total dynamic range" figure, but a ratio between the microphone's
noise floor and its output level at 1 Pascal (ca. 94 dB SPL). The maximum
SPL which the microphone can handle is not a factor; this is a different
principle from the signal-to-noise ratio of, say, a hi-fi power amplifier.
Thus anything which makes a microphone less sensitive while keeping its
noise voltage constant must, logically, reduce the microphone's signal-
to-noise ratio.

But a resistive pad at the input of a preamp, mixer or recorder will
reduce both the output noise voltage of the microphone and its too-strong
signal by the same amount, so it doesn't sacrifice signal-to-noise
performance, or at least not by nearly so great an amount, I would hope.

Peter Larsen wrote:

Why not, they track with the meters on my SV3800 when I feed a DA-P1 a
digital signal and indicate clip when it does it. And it isn't clipped
if it hasn't indicated that it was.

THAT's a bad sign. The SV3800 meters are notoriously wrong.
--scott


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

Scott Dorsey wrote:

Peter Larsen wrote:

Why not, they track with the meters on my SV3800 when I feed a DA-P1 a
digital signal and indicate clip when it does it. And it isn't clipped
if it hasn't indicated that it was.

THAT's a bad sign. The SV3800 meters are notoriously wrong.

Mine must be defective then, because the waveform only looks clipped on
screen when clipping has been indicated ... O;-)

--scott


Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********

In article ,
(Ty Ford) wrote:

In Article , (Scott Dorsey)
wrote:
In article znr1071336745k@trad, Mike Rivers wrote:
In article
writes:

What's the big deal about changing surface mount
resistors other than the difficulty finding the in small quantaties...

Anyone have a schematic of the beast?

You've just identified the second difficulty. Sony used to be
pretty free (like, for free) with their service manuals for analog
recorders, but I don't know what the situation is with digital
equipment. Why not call the service or parts department and see if you
can order a manual.

Tascam has a service manual for about $20.

I don't have one, but I do have a service manual for my old DA P-20, and
it had a real resistive pad on the front end of the mike preamp, not just
a gadget that changed the feedback.
--scott


I lost the original poster on this, but having been in a VERY similar
situation with the DA-P1, I found that sources loud enough to cause the
record level to be backed off to 2-3 meant you HAD to use the on-baord pad.
The record levels would NOT show overs, but the recordings were obviously
clipped. It's in the manual.

Regards,

Ty Ford


Well, I dunno. A friend gave me a recording of a string quartet concert he
made on a new DA-P1, feeding an AKG 422 in XY into it. Sounds OK to me -
no clipping or obvious noise. Don't know what the level controls were set
at but the highest peak was about -3dBFS.

Looks like more of a case of YMMV.

--
Mike Clayton

In article writes:

A friend gave me a recording of a string quartet concert he
made on a new DA-P1, feeding an AKG 422 in XY into it. Sounds OK to me -
no clipping or obvious noise. Don't know what the level controls were set
at but the highest peak was about -3dBFS.

As has been discussed here, the problem isn't that the peaks reach
-3dBFS, it's how they get there. A string quartet with a mic that's
placed at a reasonable distance so there's good balance among the
instruments and between the music and room ambience will probably not
slam the level into the front end of the recorder. If the clipping
doesn't occur there, it's highly unlikely that clipping will occur
anywhere else until full scale level out of the A/D converter is
reached.

It's not a matter of YMMV, it's a matter of knowing your equipment and
using it properly.


--
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