Just for the record, my measurements are with iFi iUSB Power. Seems to clean up the output when I compared with/without.
Distortion figures also depend on the modulator used, IIRC I used HQPlayer's "ASDM5" modulator for the measurements because I've been using it for bunch of other measurements too - to keep results comparable.
Distortion figures also depend on the modulator used, IIRC I used HQPlayer's "ASDM5" modulator for the measurements because I've been using it for bunch of other measurements too - to keep results comparable.
Hi,
Thanks once more for your feedback ...
I recognize your comments so just briefly to clarify: My reference was only to your fig. 1 and Jussi's fig. 5 where the difference may be from 2H at 73 dB (your fig. 1) and Jussi's ~78 dBs. I also noticed there were more noise around the 1 kHz & 2 kHz 1H & 2H in your figure as well as an overall higher noise level.
Anyway, just an FYI comment of mine.
Have a good day
Jesper
There are lots of things that could course it. let me try my best.
1 The FFT points, my fig 1 and 2 are tested long time ago with much higher FFT points. Higher FFT points combine with lower avg leads to this 'grassy' look.
2 Isolation from USB/PC, as you can see fig 4 is the one with less 'grass' compare to fig 3. The only thing changed is a I2S isolator sits between DSC1 and amanero. Jussi also pointed out the DSC1 measures better with Ifi USB power in the chain, which is a device to 'clean up' PC noises.
Can You tell me the source of SMD resistors and network boards? Or boards are DIY? I would like to make it too. Thank you!
I designed the board myself, made by oshpark. I have two sets extras but there's a design fault on it.
Here's the revised version eagle file: https://www.dropbox.com/s/g7ded6rqshdaqyb/SMD_RN.brd?dl=0
Resistors are bought from Mouser, I bought 100pcs since it's actually cheaper after the price break.
RG2012N-153-W-T1 Susumu | Mouser
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Hello mcluxun.
Have you made any progress on removing the offset voltage around the AD844 chip?
I am interested in removing the 2.2uf too. I have built another version of the DSC1 to give me more flexibility to make mods.
My new version uses Jung super regulators for all voltages, and has an isolator chip after the Amanero board. My Bootcamped Mac mini uses a highly outboard regulated linear power supply and there is a separate Jung power supply to feed 5 volts to the USB. Overall I am very happy with the result but am looking to pull out the most from the dac, hence my interest in your proposed mod.
Pictures of the DAC are posted below.
N.
Have you made any progress on removing the offset voltage around the AD844 chip?
I am interested in removing the 2.2uf too. I have built another version of the DSC1 to give me more flexibility to make mods.
My new version uses Jung super regulators for all voltages, and has an isolator chip after the Amanero board. My Bootcamped Mac mini uses a highly outboard regulated linear power supply and there is a separate Jung power supply to feed 5 volts to the USB. Overall I am very happy with the result but am looking to pull out the most from the dac, hence my interest in your proposed mod.
Pictures of the DAC are posted below.
N.
Attachments
Build ideas and suggestions
After doing some research and getting a number of opinions I'm getting ready to build a DSC1 ... the boards have been sitting on my desk for a number of months and need to be put to use!
These are my ideas:
1) JLsounds USBtoI2S, reclocked with Neutron Star 45mhz
2) Power supplies either new DIYINHK "0.9nV" or Salas Shunts
-- plan to keep r-core xformer, diodes and choke filter in a second unregulated chassis
3) Output filter either:
-a) stock op amp,
-b) replace with discrete op amp e.g. NewClassD,
-c) replace with another SK type filter e.g. Pass B-4,
-d) replace op amp with Pass DIY discrete op amp (JFET).
-e) tube op amp or SK filter
I understand that DSC2 is on way and balanced but I'd like to get some experience. What do folks think of above options?
After doing some research and getting a number of opinions I'm getting ready to build a DSC1 ... the boards have been sitting on my desk for a number of months and need to be put to use!
These are my ideas:
1) JLsounds USBtoI2S, reclocked with Neutron Star 45mhz
2) Power supplies either new DIYINHK "0.9nV" or Salas Shunts
-- plan to keep r-core xformer, diodes and choke filter in a second unregulated chassis
3) Output filter either:
-a) stock op amp,
-b) replace with discrete op amp e.g. NewClassD,
-c) replace with another SK type filter e.g. Pass B-4,
-d) replace op amp with Pass DIY discrete op amp (JFET).
-e) tube op amp or SK filter
I understand that DSC2 is on way and balanced but I'd like to get some experience. What do folks think of above options?
I was thinking about using some kind consent current sink at the pin 6 of AD844.
My first attempt has failed, I'll report back once I got it right.
Yep I used +5V DC for all the 595 chips.
3.3V DC is also used to power "clean" side of the isolator.
Here's another approach taken by a chinese DIYer:
Credit goes to op111op HIFIDIYÂÛ̳-Ò²À´Ò»¸öDSDÓ²½âÂëµÄDSC1 - Powered by Discuz!
Yes, the DSD enable output of the JLsounds needs optical isolation.
One of the problems with doing a really really good discrete output filter is that good really low noise JFets seem to be unobtainable.
Need to use separate floating power supply for each channel of the EUVL I/V converter is a significant disadvantage. This article discusses the tradeoffs: http://http://linearaudionet.solide-ict.nl/sites/linearaudio.net/files/didden-la -vol2euvl.pdf