FOXYE, you haven't mentioned what and how you have connected to the DDDAC. Are you going direct from a computer into a WaveIO and using the computer's USB to power the WaveIO board?
If you remove the USB cable from your computer, does the static noise stop?
If you remove the USB cable from your computer, does the static noise stop?
dwjames,
The computer connected to WaveIO withe usb power.
Checked it now, whan the usb cable removed from WaveIO the static noise stop.
The computer connected to WaveIO withe usb power.
Checked it now, whan the usb cable removed from WaveIO the static noise stop.
Try a short usb cable with ferrite thingies on it, see if that cuts the noise? But the best solution is to power the waveio from another power supply not connected to the computer, like in Doede's design.
Now I tried separate power supply for the WaveIO, static noise still exists. 🙁
Anyone else having this noise issue?
Anyone else having this noise issue?
I did not have any static noise at the output.
May be you have some trouble with grounding / ground loops ?
Did you connect the earth wire to the DAC / Headphone Amplifier ?
More thoughts about grounding :
I guess your PC is connected to earth wire (except you use a laptop with power supply not connected). If the DAC or one of the devices in the DAC chain connect audio gnd to erath wire you have a ground loop via earth wire. Also check your chassis vs. screw / bolt of Audio Device (e.g. DAC) PCB's, they could also connected audio gnd to earth wire.
I guess your PC is connected to earth wire (except you use a laptop with power supply not connected). If the DAC or one of the devices in the DAC chain connect audio gnd to erath wire you have a ground loop via earth wire. Also check your chassis vs. screw / bolt of Audio Device (e.g. DAC) PCB's, they could also connected audio gnd to earth wire.
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Earth wire is not connect to DAC and Headphone Amplifier.
The DAC currently installed on wood board and rca connectors isolated.
The DAC currently installed on wood board and rca connectors isolated.
do you still get the noise if you just touch the outside metal shielding of the USB cable to the outside of the USB socket on the WaveIO rather than plugging it in properly?
May be you could try to conntact only the shield of the usb and observe the nois output to figure out it is a ground issue.
with things like this try a number of things, deduction is the key word here... so try another cable, use another computer, connected another amplifier and so on. change power supplies for batteries, audiophile quality is not important, just find a way to isolate a possible cause. my suggestion is to try all this options to find out. be creative and think outside the box.
Yes.
I researched the subject a little deeper in DDDAC site on Quantization noise floor:
DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit
So played HI-REZ music in 96Khz and the noise is gone! And certainly this converter sounds better in HI-REZ.
Played regular 44.1Khz files, and the noise came back.
This appears to be the Quantization noise floor!
It turns out that the DT880 headphones is very revealing.
So maybe I'll have to sell this wonderful converter. 🙁
Most of my music is in 44.1Khz and I use headphones quite a bit.
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2 things to try.
1) you can reduce the quantization noise with 4 small film caps. Can't post details from my phone, but do a search and you should find it
2) depending on what computer and software you use, you could try software upsampling with the sox plugin, so you only send high res to the DAC
I would try point two first, was exactly my thought....
than use the Hf filter.... 22 nF between POS and NEG will do for 1 dac board
Is the noise put through through the ground connection? If you would drive the amp through the pos and neg pins would it still occur?
Regards,