Audio Precision AP Analyser series - Page 2 - diyAudio
Go Back   Home > Forums > Design & Build > Equipment & Tools

Equipment & Tools From test equipment to hand tools

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
Reply
 
Thread Tools Search this Thread
Old 8th August 2013, 07:55 AM   #11
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
I am still waiting for the IMD option to arrive and then I'll install it and start to get the A-P 2722 up and running..... -RM
  Reply With Quote
Old 9th August 2013, 12:23 AM   #12
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally Posted by RNMarsh View Post
I am still waiting for the IMD option to arrive and then I'll install it and start to get the A-P 2722 up and running..... -RM
I sent mine to AP for a fixup and went on vacation while they installed it -- came back quickly.
  Reply With Quote
Old 9th August 2013, 12:39 AM   #13
diyAudio Member
 
Loudthud's Avatar
 
Join Date: Nov 2007
Location: Near Dallas Texas USA
Can anyone describe the Compute > Linearize function?

Measuring a preamp or power amp and plotting output level (dBV) as a function of input level (mV) you get a sloping line. Use the Compute > Linearize function and you get a somewhat flat line that I think represents gain but there can be a one or two dB error. The graph below shows output vs input after the Linearize function (cyan) and in red I plotted numbers taken directly from the Sys 1's generator and analyzer. A small spreadsheet was used to do the math. It was suggested to me that the units for the output be set to dBg (dB in reference to the generator) which seems to plot more like what I would expect, and you get the gain in dB.
Attached Images
File Type: gif Ab30_10_a.GIF (52.3 KB, 369 views)
  Reply With Quote
Old 9th August 2013, 01:41 AM   #14
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally Posted by Loudthud View Post
Can anyone describe the Compute > Linearize function?

Measuring a preamp or power amp and plotting output level (dBV) as a function of input level (mV) you get a sloping line. Use the Compute > Linearize function and you get a somewhat flat line that I think represents gain but there can be a one or two dB error. The graph below shows output vs input after the Linearize function (cyan) and in red I plotted numbers taken directly from the Sys 1's generator and analyzer. A small spreadsheet was used to do the math. It was suggested to me that the units for the output be set to dBg (dB in reference to the generator) which seems to plot more like what I would expect, and you get the gain in dB.
See page 474 of the User's Manual.

When using analog sweep, use the bandpass filter and set the detector to anything but 'auto'
  Reply With Quote
Old 13th August 2013, 12:33 AM   #15
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Well the IMD option boards just arrived today. new software and hardware and learning curve will keep me entertained for awhile. Soon, I hope to be able to characterize the ADC soundcards and QA400 et al for thier accuracy and quirkiness with harmonics below -100db.
Ultra-low distortion signal source/generator and then measuring it has been a long road here for me. It looks like i have close to what I need now.... with the ShibaSoku and the new A-P2722. I will find their limits and push them.
30-40 years ago I was at the 339A limit for measuring amp distortion.... .0018% THD. Had to give up trying to measure it at that time and actually just went on to do other things. Now we can meaure better and I have the time back again to see what can be done on a second Go-Around.

Then, we can start to make fabulous CFAmps and distortion cancelling cicuits with assurance that the tests are accurately telling us what the DUT is doing.....

[Phew! Glad I'm doing this while i am still young and have the stamana and energy for it.] :-)


Thx-RNMarsh

Last edited by RNMarsh; 13th August 2013 at 12:38 AM.
  Reply With Quote
Old 14th August 2013, 05:21 PM   #16
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
The software doesnt run on my new i7. Got to call them. maybe its the USB3.0? or new WIN? but software runs the A-P with my 10+ year old WINXT . What ever happened to the idea of P-N-Play when you really need it to work? Jeez.
-RNM

Last edited by RNMarsh; 14th August 2013 at 05:23 PM.
  Reply With Quote
Old 14th August 2013, 05:59 PM   #17
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
Blog Entries: 3
You may need to run it in administrator mode. Also 32 bit vs. 64 bit? Run in compatibility mode for XP?

It seems there are three generations of software for three distinct product generations. The system one, the 22/27 series and the new digital variations. The new box is really a soundcard with autoranging inputs. Its good (-110 or better loopback harmonics) but not 27 series distortion. They consider it a bargain at $6K, $11K with all the software. However a tweaked emu 1616m could have the same performance and used with something like ARTA or HPworks get the same results. (I find the mixer for the EMU really difficult but that's me.)
__________________
Demian Martin
Product Design Services
  Reply With Quote
Old 15th August 2013, 02:52 AM   #18
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Quote:
Originally Posted by 1audio View Post
You may need to run it in administrator mode. Also 32 bit vs. 64 bit? Run in compatibility mode for XP?

It seems there are three generations of software for three distinct product generations. The system one, the 22/27 series and the new digital variations. The new box is really a soundcard with autoranging inputs. Its good (-110 or better loopback harmonics) but not 27 series distortion. They consider it a bargain at $6K, $11K with all the software. However a tweaked emu 1616m could have the same performance and used with something like ARTA or HPworks get the same results. (I find the mixer for the EMU really difficult but that's me.)

You are correct.... all those things PLUS it wont work on WIN 8 unless I go to thier site and find another piece of software to download (patch?). But even so the expensive Dolby option wont work yet with WIN8. [not that i need that option... but really..... for the price?]

A 6K sound card? Wow. -110dB? ... not so Wow. Not including software? Underwhelmed.

That brings me to an interesting observation today.... while using the old XT-Pro system for the 2722... I plugged the ShibaSoku generator into the 2722. No 2H or 3H seen ?!? Both ShibaSoku's are a bit high by current standards on the noise..... I complained about it with the 725 analyzer and wanted to clean it up some with new, low noise opa in the filters and analog outputs to the monitor port. The gen is similar but Ok at -130dB re 1v ref on the FFT from the A-P 2722. I'll be able to verify more closely and get a better handle on it once i get the 2722 running on the new i7 PC. I sure hope I dont end up with three systems and three very different results.

-Richard

Last edited by RNMarsh; 15th August 2013 at 03:00 AM.
  Reply With Quote
Old 16th August 2013, 04:21 AM   #19
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Default Variations in Harmonic measurement levels --

Getting no-where fast with the A-P 2722 software. No time for this.... calling A-P Tech support to hold my hand..... WIN 8 plus a new A-P... both software to learn at the same time (?).

But, I did some other tests today - regarding the levels of harmonics.

First is the ShibaSoku 725D. it shows the 2H from the ShibaSoku generator as -125db and the 3H as -138dB

The second is similar technology from Panasonic's model AV-7722A analyzer. It shows the 2H as -132dB and 3H as -135dB.

The affect of the notch is most likely cause for the difference... especially for the closest harmonic to the notch frequency (the 2H).

The ShibaSoku would be the more accurate one with less attentuation of the 2H by about 7dB.


Thx-RNMarsh

Last edited by RNMarsh; 16th August 2013 at 04:23 AM.
  Reply With Quote
Old 16th August 2013, 04:47 AM   #20
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
Blog Entries: 3
richard-
Your making an assumption that the Shibasoku 725 isn't generating some second harmonic.

You may be able to verify the filter by introducing a second signal at levels around -100 dB to -120 dB near the second harmonic and see if they appear in the monitor output. You should be able to verify the noth filter response at H2. In the distortion analysis they are ignored until they phase modulate the harmonic and then you get weird results. (Beats) Its really hard to know who is generating which harmonic when both devices are around the same level. Since both the analyzer and the generator use a similar amplifier circuit they would have similar distortion signatures I suspect. The three stage notch in the Shibasoku means that the autotune will be less of an issue. I suspect it only works on the third stage.
__________________
Demian Martin
Product Design Services
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
What are these resistors good for? AP precision axial metal film Rodeodave Parts 1 27th August 2010 08:24 PM
Visual Analyser, LX.1690 Analyser kit and other MAGICS!!! fotios Parts 8 18th March 2008 01:48 AM
Visual Analyser & Nuova Elletronica LX.1690 KIT Oscilloscope + Spectrum Analyser fotios Solid State 25 9th March 2008 07:35 PM
Audio analyser Mattwong Parts 8 19th December 2003 09:24 PM


New To Site? Need Help?

All times are GMT. The time now is 08:16 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2