Weiliang DAC7

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Bought in Diyhifishop a Weiliang DAC7 with several addons like OPA627, 1PPM 12M TCXO and an interface CM6631 USB module (driver-CM6631_6631A 1.01). Works well, sound clear, detailed and firm. But two problems occurs and hinders its use both windows7 as win8 (x64)& Foobar2000@WASAPI push mode:

- Often when I boot up the PC driver CMedia not locate the DAC via USB, then is 44.1 @ 16 bit, but it should be 192K @ 32bit. To resolve, I have to unplug the USB cable and then reconnect.

- Playing music, when change sampling frequency 44.1KHz for any other, makes a huge bang, and may even damage the speakers.

Forgive me for my bad english.
Can anyone help us please?
 
Hi. For the bang noise you can use pin 21 of the chip dac (WM8471) to drive a transistor or better a relay to shortcircuit the analog output (after the analog output stage): when the spdif signal is not present or not stable due the shortcircuit also the bang noise will be eliminate. When the spdif signal will be stable the transistor or the relay will eliminate the shortcircuit and you can hear the music.
I have a question for you: I have bought 2 units of this dac (equipped with CM6631 usb module) from Minishow seller. The unit works fine but I have a problem with the CM6631 when I try to play wave files at 192khz 24 bit. The unit works but several times is possible to hear scratches noise. These noises are not preriodic and are not dipendig on level of digital signal. I think there is a problem between the unit and the computer (TOSHIBA TECRA and WINDOWS7 64 bits but with other Pcs tested the resault is the same) and someone told me that the problem could be in driver or (more probably) in the firmware. Do you have the same problem?
Do you have a solution (maybe a specific firmware and a guideline to install it) to fix this problem?
Thank you.
R. Marin.
 
R. Marin thanks for your help. Likely that the manufacturer Weiliang and seller MiniShow (Min Yao) also accompany this post.We need to let these public problems! Can not implement such a solution, in case of accident, lose the guarantee of what still works. But I repeat: it is a design problem - should have foreseen this. Some music collections have different sampling - most are 44.1 KHz but still have 46, 96 and up to 192 KHz. Also it can be seen that sales are not good: in three months, fewer units sold.

As for the noise, does not happen this to me. I use the drivers from the link MiniShow (version 1.01). Another aspect is the impostante USB cable: use a very short and good shielding. If you use a common printer for example, the signal degrades and reaches disappear. See this link: http://www.ebay.com/itm/SHORT-SILVER-HIGH-QUALITY-USB-B-CABLE-LEAD-DAC-PC-LAPTOP-MAC-TABLET-/141022343293?pt=UK_Computing_USB_Cables&hash=item2 0d596307d

If you show me how can I get information about the firmware CM6631, please say that I inform with pleasure.

Another tricky issue is the version of the board DAC7 - in advertisements appearing white board v. 1.2 but the one I got is version 1.01 (black). Min Yao(Minishow) said that this is the official version from the manufacturer.

Sorry my bad English.
 
I have 2 of this

R. Marin thanks for your help. Likely that the manufacturer Weiliang and seller MiniShow (Min Yao) also accompany this post.We need to let these public problems! Can not implement such a solution, in case of accident, lose the guarantee of what still works. But I repeat: it is a design problem - should have foreseen this. Some music collections have different sampling - most are 44.1 KHz but still have 46, 96 and up to 192 KHz. Also it can be seen that sales are not good: in three months, fewer units sold.

As for the noise, does not happen this to me. I use the drivers from the link MiniShow (version 1.01). Another aspect is the impostante USB cable: use a very short and good shielding. If you use a common printer for example, the signal degrades and reaches disappear. See this link: http://www.ebay.com/itm/SHORT-SILVER-HIGH-QUALITY-USB-B-CABLE-LEAD-DAC-PC-LAPTOP-MAC-TABLET-/141022343293?pt=UK_Computing_USB_Cables&hash=item2 0d596307d

Hi,:D
Mine works ok I do have some turn on problems xp pro want to load it's drivers instead,If I don't unplug it and restart it finds the correct driver and comes to life,it won't go to 192 if your in a slow speed usb port,That make s sense,lol.When I lose signal I get white noise ,I have tried foobar and Jriver,and pandora radio with high def signal,it sounds the best,I am running in through spdif,I am still learning this dac,but it sounds good so I play it.No mods so far I have a Cm6631 card it's next!
NS
 
Without opamps in place the +ve supply works. The -ve supply shows 0.58 V and hardly varies with the pot. It does vary, from about 0.56V to 0.585V !
The two LED's indication incoming power are on.
What is the dual DIP switch ? I have a USB module on it. Note that my board says V1.0 . ( I see a mention of 1.01 , 1.1 and 1.2 boards also !)
I'll try to trouble shoot the -ve supply tomorrow. I'm getting impatient too !;)
 
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