Connect an Audio Precision to an Amplifier.

ziranos · 29th April 2012, 07:19 PM

I recently purchased a AP Sys-1, (Model: 22A with IMD) and I am investigating the possibilities of this equipment. My question is, To perform a basic measure of an amplifier ¿of the XLR connector (both generator and analyzer) which connections should I use 1, 2 or 3?
The input of the amplifier I'm testing, it is unbalanced (two connections, signal and ground), the output is also unbalanced (two connections, signal and ground).
How should I configure the Analog Generator?

I tried:
Unbal-Float
Unbal-Gnd
CMTST

For each configuration, I get somewhat different results. Clearly I have no terminal I use, and exactly how to configure the Analog Generator for this amplifier.

Thank.

mickeymoose · 1st May 2012, 03:11 PM

Unfortunately AP obsoleted the Sys1, the Sys 2 is close (better specs). Go to Audio Precision : High Performance Audio Analyzer & Audio Test Instruments and find Audio.TST under Service & Support.
Good Luck! E

Loudthud · 1st May 2012, 10:39 PM

Quote:

Originally Posted by ziranos

I tried:
Unbal-Float
Unbal-Gnd
CMTST

For each configuration, I get somewhat different results. Clearly I have no terminal I use, and exactly how to configure the Analog Generator for this amplifier.

Thank.

Now you know that grounding makes a difference!

There is a book on the AP site, Audio Measurement Handbook by Metzler. Download it, it will answer most of your questions.

ziranos · 2nd May 2012, 08:09 AM

In a video tutorial found on the website of AP that more or less tells me as I make the connection.

I have not done any testing in light of this video tutorial, when I have banana plugs, I will make some tests to see what I get.

Bob Metzler's book is very good, but there are things that speaks very generically.

Thank you very much.

jan.didden · 2nd May 2012, 08:58 AM

Quote:

Originally Posted by ziranos

I recently purchased a AP Sys-1, (Model: 22A with IMD) and I am investigating the possibilities of this equipment. My question is, To perform a basic measure of an amplifier ¿of the XLR connector (both generator and analyzer) which connections should I use 1, 2 or 3?
The input of the amplifier I'm testing, it is unbalanced (two connections, signal and ground), the output is also unbalanced (two connections, signal and ground).
How should I configure the Analog Generator?

I tried:
Unbal-Float
Unbal-Gnd
CMTST

For each configuration, I get somewhat different results. Clearly I have no terminal I use, and exactly how to configure the Analog Generator for this amplifier.

Thank.

Obviously you would used the unbalanced connection. You can try float or unfloat to see which has highest S/N.
The connections on the XLR are standardised and available on the 'net.
In such situations, I also have used BNC-to-banana adapters into the S1 front panel banana jacks.

jan didden

ziranos · 2nd May 2012, 08:23 PM

So far, I've been doing is using the XLR. But I have as I make clear the terminal configuration and I use the XLR connector.

I've done several tests to the same amplifier, using different connections and XLR configurations, but I get different results, and I'm a bit lost, since it is not exactly all the testing I've done, what is the more correct or true. Of all the graphics that I have obtained, which does not correspond to the actual characteristics of the amplifier under test.

Is it possible to buy or ride any amplifier (which is cheap or easy to assemble), and compare the measurements made to this amp with my instrument measurements obtained with AP-1 Sys?. This test would be ideal for clearing Any doubt.

My instrument Sys AP-1 passes all tests the manufacturer is more, the graphs obtained match perfectly to provide the manufacturer's procedure or self-check test.

Thank you.

Loudthud · 09:29 PM

If you do the distortion vs power level graphs, look at the level where the distortion starts to rise, typically around 1 Watt (but could be lower). That's where noise starts to dominate. You want the lowest noise

Here's a thread where I show my setup: Audio Precision System One woes

ziranos · 13th May 2012, 11:54 AM

I found the information he sought. It is in great detail in the following document "8211_1_.0029_P1_PA_Users_Manual.pdf" and also in "AUDIO PRECISION Portable One Plus Access User.pdf" is basically the same document.
The information appears on pages 6-8 to 6-11, and is perfectly explained.

Another thing,
The manufacturer Texas Instruments has test plates, and mounted amplifier, to which has already tested, which are published in the document "sloa068.pdf". Post testing to integrated amplifiers TPA731, TPA2000D1, and TPA711 TPA0211. Testing is done with Audio Precision SYS 2.
It can be a good idea to have a board test these amplifiers to contrast the information from which I can get with my Audio Precision System.

Does anyone have a better idea?

thank.

29th April 2012, 07:19 PM	#1
ziranos diyAudio Member Join Date: Apr 2012	Connect an Audio Precision to an Amplifier. I recently purchased a AP Sys-1, (Model: 22A with IMD) and I am investigating the possibilities of this equipment. My question is, To perform a basic measure of an amplifier ¿of the XLR connector (both generator and analyzer) which connections should I use 1, 2 or 3? The input of the amplifier I'm testing, it is unbalanced (two connections, signal and ground), the output is also unbalanced (two connections, signal and ground). How should I configure the Analog Generator? I tried: Unbal-Float Unbal-Gnd CMTST For each configuration, I get somewhat different results. Clearly I have no terminal I use, and exactly how to configure the Analog Generator for this amplifier. Thank.

9th May 2012, 09:24 PM	#7
Loudthud diyAudio Member Join Date: Nov 2007 Location: Near Dallas Texas USA	If you do the distortion vs power level graphs, look at the level where the distortion starts to rise, typically around 1 Watt (but could be lower). That's where noise starts to dominate. You want the lowest noise Here's a thread where I show my setup: Audio Precision System One woes Last edited by Loudthud; 9th May 2012 at 09:29 PM.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Audio Precision System 1	mickeymoose	Swap Meet	4	23rd April 2010 06:47 PM
quick connect audio	loninappleton	Parts	6	28th July 2009 02:51 PM
Audio Precision Portable Plus	tritosine	Swap Meet	9	28th February 2009 10:04 PM
how to connect a sub on a 2 channels amplifier	Mikka	Multi-Way	1	19th June 2003 10:27 AM
Audio Precision schematics?	jan.didden	Everything Else	4	20th September 2002 09:30 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

1st May 2012, 03:11 PM	#2
mickeymoose diyAudio Member Join Date: Nov 2008	Unfortunately AP obsoleted the Sys1, the Sys 2 is close (better specs). Go to Audio Precision : High Performance Audio Analyzer & Audio Test Instruments and find Audio.TST under Service & Support. Good Luck! E

2nd May 2012, 08:09 AM	#4
ziranos diyAudio Member Join Date: Apr 2012	In a video tutorial found on the website of AP that more or less tells me as I make the connection. I have not done any testing in light of this video tutorial, when I have banana plugs, I will make some tests to see what I get. Bob Metzler's book is very good, but there are things that speaks very generically. Thank you very much.

2nd May 2012, 08:23 PM	#6
ziranos diyAudio Member Join Date: Apr 2012	So far, I've been doing is using the XLR. But I have as I make clear the terminal configuration and I use the XLR connector. I've done several tests to the same amplifier, using different connections and XLR configurations, but I get different results, and I'm a bit lost, since it is not exactly all the testing I've done, what is the more correct or true. Of all the graphics that I have obtained, which does not correspond to the actual characteristics of the amplifier under test. Is it possible to buy or ride any amplifier (which is cheap or easy to assemble), and compare the measurements made to this amp with my instrument measurements obtained with AP-1 Sys?. This test would be ideal for clearing Any doubt. My instrument Sys AP-1 passes all tests the manufacturer is more, the graphs obtained match perfectly to provide the manufacturer's procedure or self-check test. Thank you.

13th May 2012, 11:54 AM	#8
ziranos diyAudio Member Join Date: Apr 2012	I found the information he sought. It is in great detail in the following document "8211_1_.0029_P1_PA_Users_Manual.pdf" and also in "AUDIO PRECISION Portable One Plus Access User.pdf" is basically the same document. The information appears on pages 6-8 to 6-11, and is perfectly explained. Another thing, The manufacturer Texas Instruments has test plates, and mounted amplifier, to which has already tested, which are published in the document "sloa068.pdf". Post testing to integrated amplifiers TPA731, TPA2000D1, and TPA711 TPA0211. Testing is done with Audio Precision SYS 2. It can be a good idea to have a board test these amplifiers to contrast the information from which I can get with my Audio Precision System. Does anyone have a better idea? thank.