WEILIANG DAC5 - WM8741 & Tenor TE7022

I haven't double checked yet but it appears everything else came in the first shipment.

I did get a couple early responses from good.feedback - he told me regular emails through his yahoo address sometimes end up in his trash folder:rolleyes: The messages that got through were on the eBay response system.

alkasar, I just bought (Sunday) a second JC-2 preamp kit and an R-core trani for use with DACs from mindshadow. A world of difference in the entire transaction. Already received USPS tracking info.

I have the 1K resistors but the 33 ohm and some 150s are the closest my stash has to offer. Does anyone think those are close enough, or is ordering the exact value the best option?
 

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I'm quite sure that only one dual op-amp is being used in the new version instead of one dual plus two singles. Maybe something like this:

4_to_2.gif
DAC5 still has 3 slots for dual opamps, it probably still has the low pass filter.

DAC6 output stage however looks similar to the above schematic... actually very very similar. Even part numbers are the same. You have some magic to get schematics Dave ;)
DAC6 has a variable resistor instead of fixed R27 or R34, to adjust offset. If I am not wrong, this is only to unbalance.
I'll plug DAC6 tomorrow and run some listening tests.
 
alkasar, you can do a frequency sweep with an oscilloscope and frequency generator.

You just have to plot the test points manually on graph paper.

Get some Log-Log grapah paper.

Set the test tone to 10Hz at -10dB and measure the output. Plot on paper.
Set the test tone to 20Hz at -10dB and measure the output. Plot on paper.
Set the test tone to 50Hz at -10dB and measure the output. Plot on paper.
Set the test tone to 100Hz at -10dB and measure the output. Plot on paper.
Set the test tone to 200Hz at -10dB and measure the output. Plot on paper.
Set the test tone to 500Hz at -10dB and measure the output. Plot on paper.

Continue through 20KHz.

If RightMark won't let you specify a frequency and amplitude, try AudioTester. I've usd it for several years and iirc the demo version will allow you to set these, but you can't save any plots. Since you are manually generating the plot it won't matter.

Download Page
 
thanks for the hint.
I once had a try with audiotester and didn't like it. Can't remember why. Nevermind : Rightmark RMAA does both : multitone and swept sine. It's not shown in the html report but it is visible in the application.

I have done some listening tests with DAC6. It plays very nicely. I have the feeling that there are more details in the high frequecies than my other dac (AD1955) but hard to tell as I can not do an A/B test.

Here are some measurements. All measurements are done on a Laptop running XP with an USB EMU0204 used as input device.

RMAA measurements
DAC6 measures OK but but nothing fantasitc compared to the EMU0204.

Summary comparison
2012-07-07_1938.png


full report
RightMark Audio Analyzer test: comparison

square wave
I also measured some sinewave and squarewave response, eventhough I have no clue how to interprete results :rolleyes:

For this, I use Visual Analyser software. A very powerful and very confusing tool... kind of a virtual scope on pc.

green wave is left channel, with 1kHz square wave
red wave is Right channel, with 1kHz sine wave

Input device is EMU0204 configured at 48kHz (bandwith 24kHz) or 96kHz (bandwith 48kHz).
Output device is either DAC6 or EMU0204 (loopback)

here are the screenshots. Obviously result depends on bandwith.

dac6 with 24kHz bandwidth
2012-07-07_1918.png


dac6 with 48kHz bandwidth
2012-07-07_1914.png


EMU0204 in loopback, 48kHz bandwidth
2012-07-07_1908.png


hope this helps,
Al
 
To all - I read back through all the pages here and only found a few comments on the actual sound quality of this DAC. The test/graphs being highly significant, don't address what we are all most interested in - what it sounds like.

Can/will anyone post some subjective impressions/comparisons of what they hear with this unit?

Thanks
 
Got lights but no sound.

Unfortunately, I started out with a problem. As always I did first power up using a dim bulb tester which indicated a short somewhere. I found a solder bridge on one capacitor (A). With that fixed, there was no fault detected by the bulb but still no light on the power LED. Reversed the polarity of that and the other two LEDs and got power indication.

The USB LED lights when that cable is connected, and the "SP" LED lights up when S/PDIF RCA from computer is attached.

DC offset reads 0.00 mV for right ch and 6.3 mV on left. There are no hot spots detected by an IR thermometer or by placing my hand over the board.

On USB - no sound or hum can be heard. Driven by the RCA, a very faint, scratchy non-musical ghost impression of what's being played can be detected through the speakers.

Opamps at "C" call for OPA624 and are correct. Those at "B" call for OPA2604 as marked on the PCB, but one OP275-G-811-G4428 and one OP275-G-903-G6404 came with the kit.

I didn't get any documentation, and my assumption that the red toggle was a power switch was proven incorrect. In the down position the SP LED is active and off when lever is up. It must be a mode switch for the tenor module???

As always, I'm open to all help and suggestions.

P.S. My eBay supplier still hasn't un-disappeared himself but I will shoot this post off to the other vendor in hopes he may offer some assistance.
 

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Bob, sorry it didn't just play. But this is DIY!

It seems the OP275 is a reasonable substitute for the OPA2604, given a quick glance at spec sheets.

My unit came with NE5532's at the position you marked B, and NE5534's at C. It worked just fine. If you have some of those extremely common op-amps bouncing around in your parts drawer, you might try a quick substitution to see what happens.

Otherwise, it is probably time to dig out the o'scope, if you have one. It is encouraging that you can hear something coming out, however faint and scratchy. You should be able to trace a test tone backwards from the output to the DAC chip.

Al, thanks for posting all those measurements. I continue to be impressed with the measured performance of your EMU0204. Have you listened to it playing music and comparing it to the DAC6?

Dave
 
Al, thanks for posting all those measurements. I continue to be impressed with the measured performance of your EMU0204. Have you listened to it playing music and comparing it to the DAC6?

Dave
Yes this soundcard has excellent measured performance and sounds very well too :D It's based on the well recognized AKM4396 used in many pro devices. For the price, it's a killing device.

I own quite a bunch of dacs and mostly listen via USB.
The previous winning configuration was a dir9001+AD1995 dac board. I used it with an additional board for 24/96 USB input with TE7022, built by Weiliang. Unfortunately the main dac board has a broken part, lead me to try a wolfson dac.

This experience confirmed that TE7022 gets a lot more out of USB than the traditional usb 16/48 receivers. I also own an even more powerful USB receiver based on TE8802 (24/192) twice as expensive and works asynchonously which is supposed to be the ultimate against jitter. But frankly, I could not hear any difference with 7022 wich is 24/96 only.

Listening tests are quite subjective. Use with precaution ;)
I like very much the EMU0204. Very detailed and "smooth". Very pleasant listening experience. This AKM dac is awesome :)

The ad1955 + TE7022 is the most precise dac I ever heard. Wide soundstage, clear, detailed and not aggressive. I had a CS4398 dac that was precise as well, but I found sometimes agressive.

I have not listen much to weiliang DAC6 : despite it measured not as good, in listening situation it clearly plays in the same league as the other two.


Many people think that opamp used in the output stage impacts the sound . I tried to swap the opamps in my AD1955 dac with LME49720 for example and others. I perceived no real change, at best some self-suggested perception ;) Will try with DAC6 if it makes a significant difference.
 
Hi Pete,

Unless I have a different board or mine is mislabeled, there is a different function here. I didn't try optical as I remembered what was under that socked. Could that be a tow-way connection? I would assume not as s/pdif requires two cables for in/out operation.

Also downloaded and installed USB driver from post #40. No improvement and the programs GUI says no device connected.

The "Off Noise" zip is a recording of a horrible sound produced by unplugging the DAC with amp/speakers on. Maybe someone can confirm if it is normal for this unit.

Thanks for the suggestions on opamps. I'll order a few and try them. As some of the regs in the kit were used (all new now) there is no telling what condition opamps were in.
 

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Thanks Pete, I have V1.3 and can see many differences compared to yours. The output/opamp sections look the same but the input, crystal and cap arrangements are not the same circuits.

I did send a message to mindshadow who may have some knowledge of the earlier versions. Hope he replies.
 

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Bob,

I listened to your "off noise." Sure sounds awful. Is this what you get when you turn off power to your DAC5? When I switch power on and off to mine, it seems absolutely quiet; no noticeable sound comes from the speakers.

Have you checked the DC output from all the voltage regulators? Have you confirmed that all polarized capacitors are installed correctly? Have you checked the + and - DC supply on all ICs?
 
so the regulators are soldered on the bottom side. Interesting.

There is something weird: the output of LM317 should be around +12Vdc to ground. (7.9V is not correct). LM337 around -12V (it outputs positive voltage !).
7808 arounf 8Vdc . Not sure what 1085 is used for, but negative voltage on all pins is wrong.
Check the regulators datasheets to findout pin order and meaning to identify input and output. lm337 negative regulator pin order is different from lm317 positive regulator. I don't think you can mess the orientation on the board.
do you measure voltages to ground ? is the transformer wired correctly ? are the rectifying diodes all in the right orientation ?
 
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I just rechecked the schematic : the 6 small regulators at the bottom are 5x 3V3 and 1x 5V regulators. They should have 8V as input (coming from 7808).
7.91V is correct. The bottom measurements are ok.

ps:1085 is 5V regulator used for wm8741 analog. You should measure 5V at it's output.