QuantAsylum QA403 tests
Tested my GRLV noise level with the QA403 by connecting it directly with BNC test leads.
The maximum DC input of the QA403 is 40 VDC.
Measured the positive and negative voltages separately to see each noise level.
Used the left positive input BNC and put a terminator on the negative input BNC.
Installed software from https://github.com/QuantAsylum/QA40x/releases/download/1.201/setup_QA40x_1.201.exe
Start app and Select File-> Devices-> QA403
Select File-> New Settings, Set the FFT size to 128k, the full scale input to 0 dBV, and hit Run.
The first image is with the 36" BNC test leads alligator clips shorted together.
The second image is the QA403 connected to the GRLV with no load.
The third image is the GRLV with CFA2 as the load.
Have less than 8 uV RMS Volts on each output.
Was able to run RMAA on the QA403 by installing ASIO drivers.
https://github.com/dechamps/ASIO401
Install https://github.com/dechamps/ASIO401/releases/download/asio401-2.0/ASIO401-2.0.exe
Have to adjust the input/output scaling with the configuration file ASIO401.toml in
the Windows user profile folder; for example: C:\Users\Your Name\ASIO401.toml
Make sure the file doesn't have .txt on the end of it.
My settings for the RMAA loopback cable tests are:
fullScaleInputLevelDBV = +6.0
fullScaleOutputLevelDBV = -2.0
Adjust levels when testing an amplifier with gain.
The input values can be: 0.0, +6.0, +12.0, +18.0, +24.0, +30.0, +36.0 and +42.0
The output values can be: -12.0, -2.0, +8.0 and +18.0
Install RMAA https://audio.rightmark.org/downloads/rmaa6.exe
Right click and Run as administrator.
Start it and select ASIO401 for input and output device.
Select 24 bit and 48 kHz.
Install four coax bnc loopback cables from output to input on the QA403.
select Playback/Recording icon.
start test if signal levels are good, otherwise adjust levels in ASIO configuration file.
when test is done, save to location.
Generate a RMAA test report with the paperclip icon.
The test report has misspelled configuration signal as singal.
I used hexinator app to edit the rmaa6 executable C:\Program Files (x86)\Rightmark\rmaa6
Select Edit, Find, singal at 496C00
Change the hex code 6E 67 to 67 6E and save.
Here are the results of the RMAA balanced loopback tests in the last image.
A picture of the QA493, GRLV, CFA2 is the fourth picture.
The GRLV has the transformers in the rear box and the regulators in the front box.
Two steel panels separate them to lower noise.