Hi Terry,
From my perspective, the optimal one for DIY high-quality measurements is "Extended high resolution 192kHz/24bit for electrical measurements":
Extended high resolution 192kHz/24bit for electrical measurements
Looks like $100.00 usd. Not too expensive. I assume a better then stock sound card is also required. Any recommendations?
I have the Delta 1010. I know it only does 96khz but do we really need higher for measuring audio?
Thanks, Terry
Thanks, Terry
The rule of thumb for measuring equipment is it should be 10 times better than what you are trying to measure, so it's inaccuracies won't effect measurements.
This one looks good. 192KHz is mostly required for good measurement of THD at 20KHz (harmonics are 40, 60, 80, etc. KHz).
Also, self-distortion of the card is important. My card shows external analog loop THD = 0.0001%
M-audio with 0.00072% THD+N is not bad at all. Although - it would be interesting to measure the external loop distortion at, say, 1, 10, 20 KHz.
Good to hear. This is still just a hobby for me and the building is my favorite part although the testing is interesting and fun as well. I still need to buy a new tower so I likely won't be buying a different sound card anytime soon. I will buy the software.
Thanks again, Terry
Cool - it will give you an ability to see some objective differences between the designs in terms of spectrums, harmonic profiles, THD / IMD levels, MLS multi-tone signal handling.
Make sure the ASIO driver is in place for the card - it gives the best possible precision in measurements.
Last edited:
I need a laptop compatible USB card and was looking at Scarlett solo 2nd gen. It supports 192k with ASIO driver. Limitation might be how clean is psu when powered via USB. Although internal cards are at mercy of AT switching supply.
Is this good enough or do I need one with independent power supply?
Solo 2nd gen:
https://www.amazon.com/gp/aw/d/B01E6T56CM/
Is this good enough or do I need one with independent power supply?
Solo 2nd gen:
https://www.amazon.com/gp/aw/d/B01E6T56CM/
This one has some impressive specs. It even comes with extra op amps for custom tuning. https://www.bhphotovideo.com/c/product/1087539-REG/asus_essencestxii_essence_stx_ii_sound.html
Impressive specs by the way:
http://dlcdnet.asus.com/pub/ASUS/Audio_Card/Essence_STX_II/E9122_Essence_STX_II_User_Manual.pdf
Very good for the price range.
You guys don't have issues with the ADC/DAC card being connected to a noisy PC bus and powered by a noisy PC power supply? I know there are guys working to use complex shunt regulated PSU's for their DACs to get noise/ripple below 50uV etc. I have a cheap USB powered DAC and can hear the noise vs when I use a DAC powered with a clean toroidal and filtered and regulated even with a 7805.
They must have some good noise suppression on those sound cards.
They must have some good noise suppression on those sound cards.
I believe my card is equipped with a good regulator, plus it's got balanced inputs / outputs.
If there's no some ground loop, arranged by me 🙂p), it's very quiet, even if I use only one side of the balanced input.
We had a request for making sure NS Modular runs fine at 2 ohm load at low frequencies, so Jeff has quickly tested NS Modular + X4 VFA.
That's what he wrote after the test 😀
"You've designed a tank! 595W (34.5V RMS) at clipping at 50Hz with 63V rails into 2 ohms. It didn't really even get that warm on a 10 second run. I ran it down at 30Hz also."
Pretty tough thing
😱
That's what he wrote after the test 😀
"You've designed a tank! 595W (34.5V RMS) at clipping at 50Hz with 63V rails into 2 ohms. It didn't really even get that warm on a 10 second run. I ran it down at 30Hz also."
Pretty tough thing
😱
I'm a little jealous. I'm sitting here looking at a bunch of completed boards that can't be tested. Any chance the modified OPS boards will be done soon?
Your boards will be on their way once I get some time to slip out to the post office.
Back to the amplifier please.
I wonder if any improvement expected using a separate power supply for the vas stage.
I wonder if any improvement expected using a separate power supply for the vas stage.
Last edited:
The antek transformers have a 12volt and 18 volt tap for a second vas supply.
AN-6450 - 600VA 50V Transformer - AnTek Products Corp
AN-6450 - 600VA 50V Transformer - AnTek Products Corp