Audio Precision AN-1A/1B

[Hardi]

Does anyone here used S1 or S2 with the last version of AN-1, CD player tests (downloadable from AP server) in addition with the CBS CD-1 Standard Test Disk?
The CBS20_S1.apb and also the CBS20_S2.apb seem to be buggy. I asked AP, but these Analyzers are no longer under support. It is NOT a hardware problem, but definitely a Problem with these procedures. I was able to fix a little error in the S2 version (Analyzer autorange off), but the main problem is still there. Bad calculation of the delta value.

I know that this is something really special, and i have little hope. Maybe someone can offer me the classic AN-1 for S1.exe ?

regards
Bert

 

[jan.didden]

Check with member @Audio1Man - he may be able to help you out.

Jan

 

[Hardi]

Stereophile used the old AN-1 as long as they had a System One with S1.exe in the lab. Some other sources showing this nearly 30 Year old "procedure" as well.
Never seen a "fade to noise" plot made with AN-1A or AN-1B, running on APwin anywhere. That´s curious.
My AP Basic language knowledge is limited, and there might be only a "," instead of a "." somewhere in the sub routine.

Bert

 

[Mooly]

@Hardi. Your multiple accounts have been merged in accordance with the site rules of one account per user.

 

[Hardi]

OK, no problem. I didn't know that.

 

[Hardi]

Really no one using this for CD Player DAC linearity measurement? OK....CD player are kind of outdated 😉

 

[jan.didden]

I gave you a source, but you ignored it.

Jan

 

[Hardi]

Sorry, but i asked Duke jears ago. He wasn’t able to help in this case.

I have some S1 and S2 in use and some of my Friends also. Running a procedure is no rocket science, but with little knowledge about the syntax, it´s not always easy to fix or modify. I was able to fix one small error, but not the main error.
2019 or so, i asked AP, and they really sent me a modified file, although S2 is no longer under support. Too bad that it also failed to work.
The CBS20_S2.apb and CBS20_S1.apb are the most "complex" procedures for APwin 2.24 that i know. All other procedures of AN-1B work well.
The Problem is, that you must have the CBS-1 Test Disk to run CBS20_s1 or _s2.

OK, this is really old stuff, and as it seems, i have to forget "fade to noise" Track 20 😉 But maybe someone can send me the ancient AN-1 for S1-exe ? This one must work, because there are many old plots still online.

 

[jan.didden]

OK, I will look for it in my system. Is this the CD you were looking for?
Could it be the test is called TN-1a (technote 1a)?

Edit: or run it through the DOS to APWIN translator?

Jan

 

[Hardi]

i´m afraid that disc has not the special "fade to noise" track. This track seems to be unique in the world of test discs.
It is a 500Hz amplitude sweep starting from -60dBFs to noise (with dither) in 30 seconds.

https://www.discogs.com/de/release/8312637-Various-CD-1-Test-Disc

The measuring is time controlled. It compares the measured values in the Editor with a reference table (also in AN-1) and calculates the delta. It will also exchange the Time scaling to appropriate dB values in the graph.
Data collection in Editor is OK, but there´s an Error in the delta calculation. Values are total garbage.

AN-1B contains two slightly different procedures for S1 and S2 (cascade) Systems running on APwin 2.24. 2700 Series is not supported.
The first two plots in the following link illustrate a "bad" and a "good" DAC linearity, measured on System one with the old S1.EXE and AN-1.

https://www.thewelltemperedcomputer.com/KB/Linearity.htm

Measuring DAC linearity of a "stand alone" DAC , driven by AP´s digital generator is no Problem with APwin. But for testing CD Players, you need AN-1.
And the CBS Disc

 

[Hardi]

The translator is for "converting" procedures written for S1.exe into procedures, running on APwin.
I never used this converter, but i´m nearly sure, that it will not accept the file.

i will give it a try...😉

 

[jan.didden]

It's all I have.
Then again, if you understand the provess, building the delta calculation should be doable.

Jan

 

[Hardi]

When you are familiar to the AP language programming, of course. Otherwise.....

 

[jan.didden]

It's just Basic with some additional functions.
There must be some reference books on it at AP.
If not, I can make another dive in my SSD.

Jan

 

[Hardi]

I have all of them already in original paper form, but they do not give answers to most of the commands and the structure.


I think this is the interesting part of the procedure:

Sub CalculateLinearity() 'A file is formatted for the data,the array data is loaded into it and saved as DATA.ADX.
Open (MacroDir & "\DATA.ADX") For Output As #1 'Open file and add header lines and array data, deletes previous,contents
'Write data header information
Print #1,"ViewData.at2, " & Now 'Print header line 1 for data file.
Print #1,"Anlr.Level A, Anlr.Level A, ,,,,,," & Chr$ (13) 'Print header line 2 for data file.
Print #1,"Source 1, Data 1, ,,,,,," & Chr$ (13) 'Print header line 3 for data file.
Print #1,Unit & ", " & Unit & ", ,,,,,," & Chr$ (13) 'Print header line 4 for data file.
'Load data from arrays
Counter = Counter - 1
Do Until Counter = -1 'Print data into data file.
Print #1,Format(TimeArray(Counter), "######.000000000") & ", " & Format(DataArray(Counter), "######.000000000") & ", ,,,,,," & Chr$(13)
Counter = Counter - 1
Loop
Close #1 'Close the DATA.ADX file (saves)
AP.Prompt.Hide
End Sub

Remark: Data.adx is OK with the correct "DUT" values from -60 to -130 dBFS


Sub DisplayData(Channel) 'A test result display skeleton is opened and the DATA.ADX file data
'loaded into it. Linearity is computed using a delta file with ideal level data.
'Difference from ideal is displayed on the graph. User data may be entered for the legend.
AP.File.OpenTest MacroDir & "\ViewData.at2" 'Load test result skeleton
If (Channel = A) Then AP.Anlr.RefChAdBr("V") = ChannelARef 'Set analyzer dBr value if Ch A
If (Channel = B) Then AP.Anlr.RefChAdBr("V") = ChannelBRef 'Set analyzer dBr value if Ch B
AP.File.ImportASCIIData MacroDir & "\DATA.ADX" 'import linearity data into data editor
AP.Compute.Delta.FileName = MacroDir & "\CDLinRef.ada" 'Attach the time vs. level reference file
AP.Compute.Delta.Data(1,1) = True 'Selects Column 1 data from reference file and attaches it to Col 1 of the test data
AP.Compute.Delta.Apply 'Apply delta file of time vs. ideal linearity values
AP.Data.UpdateDisplay (0) 'Display the results of the Compute Delta on the imported calculated linearity data
AP.Application.Page = 1 'Show page 1 which has the graph
'Add comments to graph legend
OldLegendText$ = AP.Graph.Comment 'Read test comment text
AP.Graph.Comment = "" 'Empty Comment section
AP.Graph.Comment = LegendText '+ OldLegendText 'Add LegendText from setup menu. 'optional - include original test legend
AP.Graph.CommentShow = True 'Show Comments
End Sub


Remark : The reference data "CDLinRef.ada" is not ascii data that can be open with a text editor like any .adx data, so i don´t know if it contain the correct ref. levels.

I ran out of ideas.

 

[Hardi]

Hello again, i´m getting closer 😉

The Problem is the generated DATA.ADX file. The beginning of the data list is shon below


All the dBr values are generated with a comma instead of a point. When i change comma against point (made it only for 20 rows) , the delta calculation and data in the graph are correct.
But i do not know what causes this problem.

As far as i understand, it could be in the bold lettered line. But if so, what exactly? I tried some changes without success.

Sub CalculateLinearity() 'A file is formatted for the data,the array data is loaded into it and saved as DATA.ADX.
Open (MacroDir & "\DATA.ADX") For Output As #1 'Open file and add header lines and array data, deletes previous,contents
'Write data header information
Print #1,"ViewData.at2, " & Now 'Print header line 1 for data file.
Print #1,"Anlr.Level A, Anlr.Level A, ,,,,,," & Chr$ (13) 'Print header line 2 for data file.
Print #1,"Source 1, Data 1, ,,,,,," & Chr$ (13) 'Print header line 3 for data file.
Print #1,Unit & ", " & Unit & ", ,,,,,," & Chr$ (13) 'Print header line 4 for data file.
'Load data from arrays
Counter = Counter - 1
Do Until Counter = -1 'Print data into data file.
Print #1,Format(TimeArray(Counter), "######.000000000") & ", " & Format(DataArray(Counter), "######.000000000") & ", ,,,,,," & Chr$(13)
Counter = Counter - 1
Loop
Close #1 'Close the DATA.ADX file (saves)
AP.Prompt.Hide
End Sub


Any ideas?

 

[Hardi]

The solution (for people outside the U.S.) : 😉

Have to change region and/or decimal separator in Windows operating system.

😎