Hi. The gea at www.sounddevices.com look nice, but a bit too pricey. Has
anyone tried, or heard good things about the M-Audio Duo - Stereo Mic
Preamp? Emusician gave it a great review, and said the pre's are very nice.
It's available with an external battery supply. Thanks

Mike

It's easy to build your own battery-powered mike pre, at any level from
"easiest to build" to "top quality"; and it simply doesn't cost very much.

James Boyk

"unibrow" wrote in message
newsb%Ua.162414$ye4.109455@sccrnsc01...
Hi. The gea at www.sounddevices.com look nice, but a bit too pricey.
Has
anyone tried, or heard good things about the M-Audio Duo - Stereo Mic
Preamp? Emusician gave it a great review, and said the pre's are very
nice.
It's available with an external battery supply. Thanks

Mike

I just purchased the Sound Devices 302 and have no need for my rarely used
Sound Devices MP-2. It's in mint condition and I will sell it for $500 if
you have an interest.
http://www.sounddevices.com/products/mp2master.htm

Charles Tomaras
Seattle, WA

Which designs do you recommend?

It's easy to build your own battery-powered mike pre, at any level from
"easiest to build" to "top quality," and it simply doesn't cost very much.

"Mike Rivers" wrote in message
news:znr1059397715k@trad
In article writes:

It's easy to build your own battery-powered mike pre, at any level
from "easiest to build" to "top quality"; and it simply doesn't cost
very much.

I wouldn't generalize to that extent. It's possible to build a decent
mic preamp that doesn't contain a lot of parts or tricky circuitry.
It's quite difficult for the uninitiated to actually turn that bag of
parts into a neat box with connectors on it and an easy way to change
the batteries when they run down. This is why there's relatively (in
proportion to the large number of users) little DIY construction these
days. It's not as easy to build electronics today as when everything
used tubes, point-to-point wiring, and there was plenty of room in the
chassis.

This is all true as far as it goes. However, I think that many of the
arguments against home construction are purely economic.

At one time you could get a Dynakit for $80 that was sonically competitive
with equipment that cost a lot more. Part of this savings was due to the
fact that equipment based on tubes and point-to-point wiring were far more
labor intensive, and most of the labor in question was US-based and
therefore more costly.

Today audio gear is most produced overseas using highly-automated methods.
Anybody want to try to duplicate a Mackie or more challenging yet, a
Behringer small console for even several times the street price?

"Arny Krueger" wrote

Anybody want to try to duplicate a Mackie or more challenging yet, a
Behringer small console for even several times the street price?

I was browsing some web stores last night and thought the exact same
thing. I don't think I could even buy the connectors for what they sell the
whole mixer for.

- Tommy

Arny Krueger wrote:

seems to indicate that the Mic2406 is vaporware. Any change in the last 20
milliseconds?

Thanks for asking, Arny.

The first production-ready unit is built -- see pictures on our Web
site. The next three are being built now, and we're starting assembly
of a 100-unit production in roughly two weeks. Parts have been coming
in for a few weeks already.

--
Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
Core Sound http://www.stealthmicrophones.com
Teaneck, New Jersey USA http://www.core-sound.com
Tel: 201-801-0812, FAX: 201-801-0912

"Arny Krueger" wrote in message
...
"Len Moskowitz" wrote in message


You might consider the Denecke AD-20 or our Mic2496. Both are very
portable and have very nice sounding pre-amps.

Please see our Web page for details.

http://www.core-sound.com/HighResRecorderNews.html

seems to indicate that the Mic2406 is vaporware. Any change in the last 20
milliseconds

Also, can we assume there are two 3-pin XLR inputs on the side of the box
that is not pictured on your web site? Will this also work for line level
inputs as a A/D convertor?

"Len Moskowitz" wrote in message

Arny Krueger wrote:

seems to indicate that the Mic2496 is vaporware. Any change in the
last 20 milliseconds?

Thanks for asking, Arny.

The first production-ready unit is built -- see pictures on our Web
site. The next three are being built now, and we're starting assembly
of a 100-unit production in roughly two weeks. Parts have been coming
in for a few weeks already.

Since people have been asking about the CL Jukebox 3 (JB3) - let me share
some initial measurements of its analog I/O. This is with the most recent
firmware.

The JB3 analog I/O is fairly symmetrical, with really good frequency
response in both directions. It's nearly ruler-flat 100-10 KHz.

Inbound, -0.5 dB @ 20 Hz and -0.3 dB @ 20 KHz.
Outbound, -2.5 dB @ 20 Hz, - 0.3 dB at 20 KHz.

The JB3 analog I/O mediocrity is in its SNR and dynamic range. SNR is around
65 dB, and dynamic range is around 70 dB. Not that different going in or
coming out.

Therefore, the use of something like the Mic2496 is virtually required for
true professional-quality recording with a JB3. The only true professional
way to get music out of a JB3 is USB-2 or Firewire.

If one were recording from in the crowd, the analog noise floor of the JB3
probably wouldn't IMO be a serious problem, given good external mic preamps.
I think the use of its so-called internal mic preamps for music has already
been thoroughly deconstructed by others.

The noise floor of the JB3 tends to have a downward slope with increasing
frequency, which seems to be a good thing. It appears to be adequate for
headphones and ear buds. Max out from the headphone jack is about 1 volt
into a high impedance load.

Just want to throw one more option out there - the RME QuadMic; 4ch of
mic preamps in 1/2 rack space for $560 (street price). I got mine a
few days ago and I have tested it around the house a few times with no
problems. Tomorrow night is the first real job that I'll use it on
and I'm hoping that I'll like it enough that I can make it a regular
part of my location rig. (to provide 4ch of mic preamps out of my
existing gear collection, I would need to drag at least 6 (SIX!) rack
spaces worth of very heavy gear. Now, all 4ch fit in a box barely
larger than an RNC. When the budget is big enough to support adequate
load-in / setup time, I'll still carry the heavy iron. But when I'm
stuck on a bare bones budget and I have to lug it all in and out
myself, this thing looks like a winner.

basic info: 4ch in 1/2 rack space with gain pot, low cut, phase
reverse and 48v switches for each channel on the front panel. XLR ins
and TRS outs with an unexplained +4/Hi gain switch on the back. (it
appears to provide an extra 6dB or so of output) RME claims that
anything that produces electric current can power this thing (you can
order a pair of wool sox in place of the standard wall wart.) AC, DC,
battery and car adapter are all provided for.

The size, weight and "fit and finish" all earn 3 star ratings; sound
quality will be left to each of you to determine for yourselves. I'll
post my opinions some time after tomorrow's session. But based on an
hour or so of listening around the house, RME achieed their primary
goal - a generally clean preamp. (Non-"flavored" preamps are somewhat
harder to evaluate than "personality preamps" if only because it can
be difficult to hear anything to comment on. But that's a good thing,
right?

steve

www.lexington125.com

In article writes:

The JB3 analog I/O mediocrity is in its SNR and dynamic range. SNR is around
65 dB, and dynamic range is around 70 dB. Not that different going in or
coming out.

I don't recall my numbers (Google it, I posted them here, but look for
the earliest post. I posted about it again, but from memory, probably
no more accurate than the above) but I seem to remember nearly 20 dB
better than that with the 0 dB line input setting, and perhaps 20 dB
worse with it set for mic input and 40 dB gain. I made some fine live
recordings using my Mackie 1402 mixer as a mic preamp. No problem with
Jukebox noise - not to say that there wasn't any, but it was well
below the music and ambient acoustic noise.



--
I'm really Mike Rivers - )

"Mike Rivers" wrote in message
news:znr1060207775k@trad
In article
writes:

The JB3 analog I/O mediocrity is in its SNR and dynamic range. SNR
is around 65 dB, and dynamic range is around 70 dB. Not that
different going in or coming out.

I don't recall my numbers (Google it, I posted them here, but look for
the earliest post. I posted about it again, but from memory, probably
no more accurate than the above) but I seem to remember nearly 20 dB
better than that with the 0 dB line input setting, and perhaps 20 dB
worse with it set for mic input and 40 dB gain. I made some fine live
recordings using my Mackie 1402 mixer as a mic preamp. No problem with
Jukebox noise - not to say that there wasn't any, but it was well
below the music and ambient acoustic noise.

I went back and searched through about 40 of your posts and finally saw a
reference to 80 dB.

There were some procedural differences - I made my measurements in a -10
environment because JB3 is basically a consumer device. This required
setting JB3 input gain at something like +8dB. From your comments it looks
like you made your recording in a +4 environment which I can easily
duplicate, but haven't done so yet.

You probably measured what zero signal noise and compared that to peak
undistorted recorded level, which is the traditional way to measure SNR.
That would be about 75 dB per my measurements. All of a sudden our results
converge quite a bit.

New age SNR is what used to be called THD+N at peak undistorted recorded
level, or a few dB down from peak and adjusted by the number of dB below
peak. The point being that noise is now measured with a large signal present
to pick up modulation noise.

Dynamic range is now measured with a -60 dB 1 KHz tone. The New Age SNR is
measured and added to 60 dB. Again, the idea is to mimic what happens with a
representative signal present.

To put things in perspective, the dynamic range of the human ear at any
point in time is about 60 dB. So, anything that has 60 dB dynamic range or
more per New Age measurements, will probably be subjectively quiet. The
noise spectrum of the JB3 appears to favor imperceptibility, being something
like pink noise.

The distortion measurements were very asymmetrical. Playback nonlinear
distortion was very low, the largest harmonics being the second and third,
both more than 90 dB down. Record THD had a similar distribution, but was
like 0.05% or only about 66 dB down. Neither is much to worry about.

In article writes:

I went back and searched through about 40 of your posts and finally saw a
reference to 80 dB.

There were some procedural differences - I made my measurements in a -10
environment because JB3 is basically a consumer device. This required
setting JB3 input gain at something like +8dB. From your comments it looks
like you made your recording in a +4 environment which I can easily
duplicate, but haven't done so yet.

I didn't really think about it that way, I made measurements with the
Jukebox's gain set at 0 dB because that's the way I am most inclined
to use it unless I'm recording records off the living room stereo
receiver, in which case I can push it up to +6 dB and get more level
which helps when listening on an airplane.

You probably measured what zero signal noise and compared that to peak
undistorted recorded level, which is the traditional way to measure SNR.
That would be about 75 dB per my measurements. All of a sudden our results
converge quite a bit.

Yes, that's what I did.

New age SNR is what used to be called THD+N at peak undistorted recorded
level, or a few dB down from peak and adjusted by the number of dB below
peak. The point being that noise is now measured with a large signal present
to pick up modulation noise.

Dynamic range is now measured with a -60 dB 1 KHz tone. The New Age SNR is
measured and added to 60 dB. Again, the idea is to mimic what happens with a
representative signal present.

Interesting. I'll have to try measuring some things like that. Where
do these procedures come from? Is this published by one of the
standards organizations, or did it just grow?

To put things in perspective, the dynamic range of the human ear at any
point in time is about 60 dB. So, anything that has 60 dB dynamic range or
more per New Age measurements, will probably be subjectively quiet.

This is why I never really worried too much about S/N ratio
measurements with modern equipment. There are too many other things
that can be worse problems. However, when the JB3 is operated in the
"Mic Input" mode, quiescent noise (recorded level or monitor output
with zero input) is quite objectionable, and is objectionable in the
presence of normal signals.



--
I'm really Mike Rivers - )

"Mike Rivers" wrote in message
news:znr1060264980k@trad
In article
writes:

There were some procedural differences - I made my measurements in a
-10 environment because JB3 is basically a consumer device. This
required setting JB3 input gain at something like +8dB. From your
comments it looks like you made your recording in a +4 environment
which I can easily duplicate, but haven't done so yet.

I didn't really think about it that way, I made measurements with the
Jukebox's gain set at 0 dB because that's the way I am most inclined
to use it unless I'm recording records off the living room stereo
receiver, in which case I can push it up to +6 dB and get more level
which helps when listening on an airplane.

When I do things like that I turn the LPs into .wav files using a PC, get
the levels right there, and then move the .WAV files onto the JBS via USB-2.
Right tool for the job, faster transfers, and all that.

You probably measured what zero signal noise and compared that to
peak undistorted recorded level, which is the traditional way to
measure SNR. That would be about 75 dB per my measurements. All of a
sudden our results converge quite a bit.

Yes, that's what I did.

New age SNR is what used to be called THD+N at peak undistorted
recorded level, or a few dB down from peak and adjusted by the
number of dB below peak. The point being that noise is now measured
with a large signal present to pick up modulation noise.

Dynamic range is now measured with a -60 dB 1 KHz tone. The New Age
SNR is measured and added to 60 dB. Again, the idea is to mimic what
happens with a representative signal present.

Interesting. I'll have to try measuring some things like that. Where
do these procedures come from? Is this published by one of the
standards organizations, or did it just grow?

http://www.aes.org/standards/b_pub/aes-6id-2000.pdf

Sections

3.7 and 4.1.5.1 through 4.1.5.4

To put things in perspective, the dynamic range of the human ear at
any point in time is about 60 dB. So, anything that has 60 dB
dynamic range or more per New Age measurements, will probably be
subjectively quiet.

This is why I never really worried too much about S/N ratio
measurements with modern equipment. There are too many other things
that can be worse problems. However, when the JB3 is operated in the
"Mic Input" mode, quiescent noise (recorded level or monitor output
with zero input) is quite objectionable, and is objectionable in the
presence of normal signals.

Right, the so-called mic input feature of the JB3 is pretty well
deconstructed for serious work.

"Mike Rivers" wrote in message
news:znr1060287425k@trad

In article
writes:

When I do things like that I turn the LPs into .wav files using a
PC, get the levels right there, and then move the .WAV files onto
the JB3 via USB-2. Right tool for the job, faster transfers, and all
that.

Yeah, but how do you turn the LP into a WAV file other than to play
the record in real time?

Bummer, eh?

;-)

I'd have to run a cable a couple of rooms
over to connect a computer to the turntable, play the record, record
it into the PC, and then transfer it to the Jukebox. Playing it
directly into the Jukebox gets the whole job done in one step, a step
that has to be done either way. As far as quality goes, I don't care
about tweaking it just right. I'm only going to listen to it once or
twice on headphones while on an airplane anyway.

OK.

BTW, I did a measurement of the JB3 more like your way, Mike. I adjusted
the output of my source for -1 on the JBS level meters (not the
fastest-responding things in the world) with the JB3 input gain set to zero.
This turned out to be 2.25 volts RMS. I would say that the JB3 was designed
to record off the line outputs of a typical consumer CD player.

Va-va voom! 85 dB SNR measured your way. Combine that with ruler-flat
response from 100-10 KHz and a paltry -0.5 dB down at 20 and 20K, and
basically we are stylin'.

Moral of story: If you use external mic preamps and set the levels right,
the analog inputs on the JB3 about as good as the line level inputs on a
good portable DAT. This thing does seem to kinda fall off a cliff if you
play with the input level control. For optimal results never move it more
than 1 or 2 dB either way.

Thanks for the AES reference on measurements. I'll grab a copy.

It's really nice how they let you download the PDF for free. But only print
one copy, eh?

LOL!

In article writes:

Va-va voom! 85 dB SNR measured your way. Combine that with ruler-flat
response from 100-10 KHz and a paltry -0.5 dB down at 20 and 20K, and
basically we are stylin'.

Moral of story: If you use external mic preamps and set the levels right,
the analog inputs on the JB3 about as good as the line level inputs on a
good portable DAT. This thing does seem to kinda fall off a cliff if you
play with the input level control. For optimal results never move it more
than 1 or 2 dB either way.

That was my conclusion, and how I use it. Also, why I want an outboard
mic preamp. The analog input is plenty good enough to use once you get
the mic level up to a couple of volts peak, which is not at all hard
to do, even with battery power. I've been keeping an eye out for one
with digital optical output, but that's probably kind of a waste given
the rest of the system. I haven't done any torture tests on the
optical connection, but I sure wish there was a more robust analog
input connector. By trimming down the housing of some molded
connectors, I'm able to get them to fit all the way into the jack.
Gotta remember to never leave my pocket knife at home though, if I
ever need to use someone else's cable.


--
I'm really Mike Rivers - )