I have to get a new distortion analyzer for our lab. We're working on a new
hybrid asic and some pre-amp designs. Can anyone recommend one?

My partner has an older HP .. I think it is the 309. I would like something
a little newer with the capability to read very low percentages .. .01


Thanks

On Fri, 03 Mar 2006 03:28:16 GMT, "nappy" wrote:

I have to get a new distortion analyzer for our lab. We're working on a new
hybrid asic and some pre-amp designs. Can anyone recommend one?

My partner has an older HP .. I think it is the 309. I would like something
a little newer with the capability to read very low percentages .. .01

Only geezers like me still use distortion analyzers. Anybody
with ready cash buys a modern D/A + A/D card for their
computer, and software is cheap/ free.

Some things do get better.

ps: In choosing interfaces, be very conservative about
your required common-mode rejection and distortion product
bandwidths. Good generic-computer-based solutions to many
testing problems exist, but aren't *necessarily* cheap. Depends
entirely on what you need to do; if the device you need to
measure, and the "distortion" you need to measure fits available
interfaces, you're Golden.

All good fortune,

Chris Hornbeck

Chris Hornbeck wrote:
On Fri, 03 Mar 2006 03:28:16 GMT, "nappy" wrote:

I have to get a new distortion analyzer for our lab. We're working on a new
hybrid asic and some pre-amp designs. Can anyone recommend one?



see:

http://www.audioprecision.com/

Mark

"nappy" wrote in message
om

I have to get a new distortion analyzer for our lab.

We're working on a new hybrid asic and some pre-amp
designs. Can anyone recommend one?

A Windows PC with a Lynx L22, running Spectra Lab or SMAART

If the the LynxL22 is a bit salty, try a M-Audio Delta 24192.

If your software budget is zilch or close to it, RMA (Audio Rightmark) is a
free download and surprisingly effective.

My partner has an older HP .. I think it is the 309. I
would like something a little newer with the capability
to read very low percentages .. .01

Here's the residuals one obtains with a LynxTWO (a 4-channel L22) and
Spectra Lab:

http://www.pcavtech.com/soundcards/lynxtwo/

Hi,

If you are interested, I have a Sound Technology 1700A (good down to .002%
THD) and a Crown IMA that are not being used anymore. If you are
interested, email me privately and perhaps we can make a deal.

Regards,

Mark


"nappy" wrote in message
om...
I have to get a new distortion analyzer for our lab. We're working on a
new
hybrid asic and some pre-amp designs. Can anyone recommend one?

My partner has an older HP .. I think it is the 309. I would like
something
a little newer with the capability to read very low percentages .. .01


Thanks

nappy wrote:
I have to get a new distortion analyzer for our lab. We're working on a new
hybrid asic and some pre-amp designs. Can anyone recommend one?

My partner has an older HP .. I think it is the 309. I would like something
a little newer with the capability to read very low percentages .. .01

The HP334 is about the oldest box I'd recommend. It's reliable and stays
calibrated, and it goes down about as low as you'd really need to go for
THD measurements. The HP 8903 is probably the most recent distortion meter
made, and Tucker probably can sell you a used one. They are much more
convenient than the old 334.

These days hardly anyone uses a dedicated distortion meter any longer,
but use the THD and IMD functions on a general-purpose signal analyzer.
This usually has the additional advantage of allowing you to easily view
the distortion spectrum.

Seeing the distortion spectrum is much more valuable for engineering and
manufacturing test purposes, although you'll still need to do the the
traditional THD and IMD measurements for the marketing guys.

The most popular box in the audio industry today is the Audio Precision
test set although you still see the HP3562 and its ilk around. Ono Sokki
also makes a nice box, too. A lot of these units are limited by the
low-level linearity of the digital front end, though. If you really want
to go as low as it's possible to go, the 8903 may be the way to go.
--scott

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

"Chris Hornbeck" wrote in message
...
On Fri, 03 Mar 2006 03:28:16 GMT, "nappy" wrote:

I have to get a new distortion analyzer for our lab. We're working on a
new
hybrid asic and some pre-amp designs. Can anyone recommend one?

My partner has an older HP .. I think it is the 309. I would like
something
a little newer with the capability to read very low percentages .. .01

Only geezers like me still use distortion analyzers. Anybody
with ready cash buys a modern D/A + A/D card for their
computer, and software is cheap/ free.


I'd rather do it all in the analog domain.


Some things do get better.

ps: In choosing interfaces, be very conservative about
your required common-mode rejection and distortion product
bandwidths. Good generic-computer-based solutions to many
testing problems exist, but aren't *necessarily* cheap. Depends
entirely on what you need to do; if the device you need to
measure, and the "distortion" you need to measure fits available
interfaces, you're Golden.

All good fortune,

Chris Hornbeck

"Scott Dorsey" wrote in message
...

Seeing the distortion spectrum is much more valuable for engineering and
manufacturing test purposes, although you'll still need to do the the
traditional THD and IMD measurements for the marketing guys.

exactly


The most popular box in the audio industry today is the Audio Precision
test set although you still see the HP3562 and its ilk around. Ono Sokki
also makes a nice box, too. A lot of these units are limited by the
low-level linearity of the digital front end, though. If you really want
to go as low as it's possible to go, the 8903 may be the way to go.
--scott

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

"nappy" wrote in message
om...
I have to get a new distortion analyzer for our lab. We're working on a new
hybrid asic and some pre-amp designs. Can anyone recommend one?

My partner has an older HP .. I think it is the 309. I would like
something a little newer with the capability to read very low percentages
.. .01


Thanks





Thanks for your input guys.

"Mark Robinson" wrote in message
. ..
Hi,

If you are interested, I have a Sound Technology 1700A (good down to .002%
THD) and a Crown IMA that are not being used anymore. If you are
interested, email me privately and perhaps we can make a deal.

Regards,

Mark


Will do Mark. Probably this weekend. Thanks


"nappy" wrote in message
om...
I have to get a new distortion analyzer for our lab. We're working on a
new
hybrid asic and some pre-amp designs. Can anyone recommend one?

My partner has an older HP .. I think it is the 309. I would like
something
a little newer with the capability to read very low percentages .. .01


Thanks

There are some very new meters from Aaronia on the market. Have a look
at:
http://test1.contenttest.net/Spektru...sator_en.shtml
Those can handle all type of signals at a very low price and a as small
as a regular multimeter. Have SMA port for PC too...

Scott Dorsey wrote:

nappy wrote:
My partner has an older HP .. I think it is the 309.

The HP334 is about the oldest box I'd recommend. It's reliable and stays
calibrated, and it goes down about as low as you'd really need to go for
THD measurements.

I suspect that Nappy's buddy has a 339, not a 309. That's the next
model after the 334, and it includes completely automatic nulling and a
low distortion generator. It goes down to 0.01% THD full scale. I'd be
happy with one of those if anyone wants to make an even swap for my
334. g

I once worked in a shop that had a 339 which I used to borrow
frequently for aligning my tape recorders, but when I left that job and
looked for a THD analyzer of my own, all I could afford was a 334. The
newer models are too compllicated for me.

Audio Precision, period. I have a system 1. The new AST rack is great,
buy one if you really want to get to the bottom of things, the ST 1700
isn't good enough, neither is the HP's. The Prism D-Scope is also very
good.

Jim Williams
Audio Upgrades

"Mike Rivers" wrote in message
ups.com...

Scott Dorsey wrote:

nappy wrote:
My partner has an older HP .. I think it is the 309.

The HP334 is about the oldest box I'd recommend. It's reliable and stays
calibrated, and it goes down about as low as you'd really need to go for
THD measurements.

I suspect that Nappy's buddy has a 339, not a 309.

I think you're right there.. Worked with it all day today and didn't even
look at the model number.. !

nappy wrote:
"Mike Rivers" wrote in message
oups.com...

Scott Dorsey wrote:

nappy wrote:
My partner has an older HP .. I think it is the 309.

The HP334 is about the oldest box I'd recommend. It's reliable and stays
calibrated, and it goes down about as low as you'd really need to go for
THD measurements.

I suspect that Nappy's buddy has a 339, not a 309.

I think you're right there.. Worked with it all day today and didn't even
look at the model number.. !

It's fine. Hell, I use a 334 much of the time, myself. I recently shipped
the Genrad 2615 off to a museum too.

It won't go super low, but I figure if you need to go that low, the THD
number isn't really very important anyway. The combination of a 339 and
an FFT box is pretty powerful.

It's hard to beat the AP for convenience and bench space savings. The whole
AP system takes up less space than my Tek scope does.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

The Aaronia link isn't relevant to this thread; it's a spectrum
analyzer for radio frequency interference.

--best regards

Thats totaly wrong! have a look at the NF series. It covers 1Hz to 1MHz
and has a input for external signals (audio) too. Therefore ist a very
cheap and portable spectrum analyzer for Audio ;-)

David Satz schrieb:

The Aaronia link isn't relevant to this thread; it's a spectrum
analyzer for radio frequency interference.

--best regards

Now then he is wrong this time ;-)
The input is a ANALOG input. Therefore you can feed what ever you want.
Attache a bigger coil to get higher sensitivity in magnetic fields or
simply just add a AUDIO signal from your radio and the Spectran will
show it up to 1 MHz, its just as easy as that. The internal AD
converter can handle all possible signals it works like the soundcard
on the PC.


Mike Rivers schrieb:

wrote:
Thats totaly wrong! have a look at the NF series. It covers 1Hz to 1MHz
and has a input for external signals (audio) too. Therefore ist a very
cheap and portable spectrum analyzer for Audio ;-)

I saw something about audio output, and audio demodulation (so you can
listen to the radio signal that it's picking up) but nothing about an
audio input. Do you have a picture or more detailed spec sheet to
confirm that there's actually an audio input? When it talks about E-
and H-field sensitivity and earth's magnetic field sensors, I get the
impression that David knows what he's talking about (he usually does).

wrote:
Now then he is wrong this time ;-)
The input is a ANALOG input. Therefore you can feed what ever you want.
Attache a bigger coil to get higher sensitivity in magnetic fields or
simply just add a AUDIO signal from your radio and the Spectran will
show it up to 1 MHz, its just as easy as that.

I looked again and still don't see anything that suggests that it
either has an analog input or is intended for use with audio signals.
Where are you getting this information? Or do you have one and you're
actually using it in this manner. I don't even see a place to connect a
coil (I assumed it was internal) but then they really don't show very
much on the web site. If you have a link to an instruction manual or a
good picture that shows the connectors, please pass it along.

I could very well be wrong but I don't see any evidence that it can be
used in the way you suggest, other than perhaps with some modification.
That's cheating!

wrote in message
oups.com
Now then he is wrong this time ;-)
The input is a ANALOG input. Therefore you can feed what
ever you want. Attache a bigger coil to get higher
sensitivity in magnetic fields or simply just add a AUDIO
signal from your radio and the Spectran will show it up
to 1 MHz, its just as easy as that. The internal AD
converter can handle all possible signals it works like
the soundcard on the PC.

Where does the spec sheet give information about residual distortion and
dynamic range?

I looked again and still don't see anything that suggests that it
either has an analog input or is intended for use with audio signals.
Where are you getting this information? Or do you have one and you're
actually using it in this manner. I don't even see a place to connect a
coil (I assumed it was internal) but then they really don't show very
much on the web site. If you have a link to an instruction manual or a
good picture that shows the connectors, please pass it along.

I could very well be wrong but I don't see any evidence that it can be
used in the way you suggest, other than perhaps with some modification.
That's cheating!

Ok so for all folks who have tomatos on the eyes a STEP by STEP
instruction ;-)
Go to
http://test1.contenttest.net/Spektru...sator_en.shtml
Go to "SPECTRAN NF-3020". There it says " This extended version of the
SPECTRAN NF-3010 also allows analysis of EXTERNAL signal sources via
its SMA input.".
Or click "COMPLETE description". In the NEW window you can see in the
"Overview of features SPECTRAN® LF spectrum analysers" under "
INTERFACES" the feature "External signal input (screened SMA input)".
Got it?
With the SMA input you can feed what ever you want. Its like a SCOPE!

wrote:
instruction ;-)
Go to
http://test1.contenttest.net/Spektru...sator_en.shtml
Go to "SPECTRAN NF-3020". There it says " This extended version of the
SPECTRAN NF-3010 also allows analysis of EXTERNAL signal sources via
its SMA input.".
Or click "COMPLETE description". In the NEW window you can see in the
"Overview of features SPECTRAN=AE LF spectrum analysers" under "
INTERFACES" the feature "External signal input (screened SMA input)".
Got it?
With the SMA input you can feed what ever you want. Its like a SCOPE!

Right, but what is the noise floor on that at low frequencies?

If I send it DC to 100 Hz info, can I display it, and more importantly
how high is the noise floor down there and how small a bin can I create?

A lot of newer RF spectrum analyzers are rated to work down to DC, but when
you actually try it, the experience is not a pleasant one.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

wrote:

Or click "COMPLETE description". In the NEW window you can see in the
"Overview of features SPECTRAN® LF spectrum analysers" under "
INTERFACES" the feature "External signal input (screened SMA input)".
Got it?
With the SMA input you can feed what ever you want. Its like a SCOPE!

What does SMA stand for here? Is it the little coaxial connector? What
voltage level does it require? What's its input impedance?

Call me what you want, but I'll believe it when you get yours and come
back and tell us how you hooked it up and how well it works as an audio
spectrum analyzer. Everything in the documentation points to other
applications.

It might in fact work (as in make a display) but I still question
whether it will be meaningful. Maybe it'll be OK for your applications,
whatever they are.