Great job, Andrea!
And many thanks for info about E-MU card.
As alternative can use less expensive M-Audio Fast Track Pro card...
And many thanks for info about E-MU card.
As alternative can use less expensive M-Audio Fast Track Pro card...
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Can you extend the y axis below -80dB? I'd like to see the complete noise spectrum down to around -140dB.
Hi Andrea
great write-up as usual. The e-mu is a cut above. I did a similar thing a while ago but a more budget approach and consequently not as precise...but may be useful for those with less cash.
Vitalstates- Amplifiers
great write-up as usual. The e-mu is a cut above. I did a similar thing a while ago but a more budget approach and consequently not as precise...but may be useful for those with less cash.
Vitalstates- Amplifiers
Hi, vitalstates!
Your solution is quit precice, 16bit converter is too enough for THD measurements in 70dB range.
Thanks for your article.
Regards, Konstantin.
Now I have published some more informations about this project.
The my idea was to test the amplifier in a more large frequency range, until 100KHz.
I use the EMU 0404 USB with Lundahl output transformers to ear hi-resolution audio tracks and I consider it like my best source now.
The my idea was to test the amplifier in a more large frequency range, until 100KHz.
I use the EMU 0404 USB with Lundahl output transformers to ear hi-resolution audio tracks and I consider it like my best source now.
Hello,
As always, nice job.
I have a question or request.
Please tell us more about the setup of the EMU mixer software. Are there different settings for 44.1K 48K 96K and 192 K and 16 bit or 24 bit in the mixer software?
I have an EMU 1212, sorting out the mixer software looks to be a long rainy day project.
DT
On the EMU0404 USB control panel is possible set only the sample rate and it must be set to 192KHz to have the larger frequency response band.
In my webpage there is an image about the EMU0404 USB control panel.
No mixer software is available with EMU0404 USB.
Could you send me an image of your mixer ?
Hello,
Take a look at the attached link. Chapter 4 is the patchmix. It includes control of everything, bit rate, sample rate input to output routing, volume control. There is a preset that works at 16 / 44.1. I will look at the 404 shot at your linked site. Thank You.
http://www.emu.com/support/files/storage/v2_1820-1212-EN.pdf
DT
All just for fun!
You should set 24 bit and 192 KHz on the mixer panel.
The Arta software should recognize the input and output device.
The Arta software should recognize the input and output device.
Very interesting... I am about to build this:
Your PC as an Audio Analyzer: Measure THD, S/N, Power Output, etc
Don't know if it works ok though.
Your PC as an Audio Analyzer: Measure THD, S/N, Power Output, etc
Don't know if it works ok though.
Attachments
pradigmshift ,
the circuit you propose is not serious, the diodes will be destroied with higher signals so also the sound card will be compromised.
the circuit you propose is not serious, the diodes will be destroied with higher signals so also the sound card will be compromised.
It looks OK to me. Not perfectly optimum, but undoubtedly Good Enough for most use and very simple/cheap. The diode input clamps will protect the sound card; if they sacrifice themselves, they usually go short circuit, and they're 1000-5000 times less expensive than a sound card.
If the diodes have a fault these will be open for the signal so does not protect your sound card.
It is necessary a resistance before the diodes to protect these.
The 100K before the sound card introduce with the input capacitor of sound card a filter on high frequency limiting the band.
It is necessary a resistance before the diodes to protect these.
The 100K before the sound card introduce with the input capacitor of sound card a filter on high frequency limiting the band.
Disagree on all counts.
In a small minority of ultra-high pulse current failures, the diode bond wire can fuse open. But far and away the most common diode failure is short. There is a 100k resistor in series, so I can't imagine how much more resistance you'd want.
As far as HF response, the pole is formed by the 100k in parallel with the 20k resistor in parallel with the input resistance of the sound card (usually 10k) and in parallel with R2 (which can be open, 560R, or 51R) interacting with the input capacitance of the line card. If a line card has 50pF of input capacitance (which is more than any sound card in my possession), that f3 is about 300kHz with R2 open. With R2 at 560R, the HF rolloff is in the multimegahertz range.
The voltage ranges given in the schematic aren't exactly correct, but the right order of magnitude.
Thanks for the replies. The zeners are a nice choice but I will stick to the diodes, given the replies. Is there also an easy way to protect against ground faults (either faults in the amplifier/pc or accidental reversal of + and -?)
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