Had some listening tests with the QA-550 today.
First: I don't consider the differences in the digital source domain as that big. Changing DACs does a lot more to the sound than goinig from the card player to a CD drive. I'll come back to comparing the QA player with other sources later, today I went for comparing S/PDif connection with I²S. I used a DDDac with eight TDA1543 per channel, which isn't the DAC I want to spend the rest og my life with, but it isn't crap.
It has one big advantage: I can switch between I²S input and S/PDif connection (coaxial). This works very good, nearly without pops or clicks.
To make it short: I²S sounds better. There aren't worlds between it and the coaxial cable, but the difference is audible. I found the biggest improvemment is in soundstage. With I²S, it is significantly wider and deeper, things seem to be more focused. In terms of tonality, I²S is a little more shifted towards higher frequencies, S/PDif seems more compact, somewhat darker. I can't find substantial differences in dynamics. I²S seems to deliver somewhat more detail, it seems a little tidier.
The differences aren't so big that they hit the ears momentarily, I had to switch severeal times between both modes and repeat a music passage. But the difference ist there and the I²S connection gets my vote.
First: I don't consider the differences in the digital source domain as that big. Changing DACs does a lot more to the sound than goinig from the card player to a CD drive. I'll come back to comparing the QA player with other sources later, today I went for comparing S/PDif connection with I²S. I used a DDDac with eight TDA1543 per channel, which isn't the DAC I want to spend the rest og my life with, but it isn't crap.
It has one big advantage: I can switch between I²S input and S/PDif connection (coaxial). This works very good, nearly without pops or clicks.
To make it short: I²S sounds better. There aren't worlds between it and the coaxial cable, but the difference is audible. I found the biggest improvemment is in soundstage. With I²S, it is significantly wider and deeper, things seem to be more focused. In terms of tonality, I²S is a little more shifted towards higher frequencies, S/PDif seems more compact, somewhat darker. I can't find substantial differences in dynamics. I²S seems to deliver somewhat more detail, it seems a little tidier.
The differences aren't so big that they hit the ears momentarily, I had to switch severeal times between both modes and repeat a music passage. But the difference ist there and the I²S connection gets my vote.
The QLS download page now has an update which, according to Clark, will solve the problem I had with a Transcend 8GB card that I reported in post #21. I can't actually test it, as I have returned the card and got a refund on it.
However it's good to see that QLS respond well to the customer's feedback.
However it's good to see that QLS respond well to the customer's feedback.
On the Mac I'm using xACT with good results. I tried MAX but I was getting a click in between tracks, and it didn't always get the track information reliably.
Hello All:
I also have this player, which I purchased ~ 2 months ago. I initially tried using the digital coax output with this dac (using output transformers):
http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac.html
I was having problems with dropouts/pops when using the digital coax out, and basically gave up on using it for awhile. About a week ago, I tried the toslink output and voila! --no more dropouts/pops. Now that I wasn't distracted/annoyed by the player, I compared it to my CD player (Onix CD 5SE) using the digital output into the same DAC. I would give the nod in sound quality by a slight margin to the SD card player.
However, up until last night I still had issues--I have three 8 GB cards loaded with music that would not play on this player. Two, four, and sixteen GB cards played fine, but the three 8 gig cards would not. Then, I noticed there was an 'updata04' version on the website yesterday, so I updated the player with this version, and again, voila! --The eight GB cards now work.
So, I am now pretty happy with the player (especially considering the price). I just received the switchable (3, 4.5, 6, 7.5, 9, 12 VDC) regulated power supply from Parts Express, and will give that a try tonight. If anyone is interested, I will update with any improvements this provides.
Regards;
limits
I also have this player, which I purchased ~ 2 months ago. I initially tried using the digital coax output with this dac (using output transformers):
http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac.html
I was having problems with dropouts/pops when using the digital coax out, and basically gave up on using it for awhile. About a week ago, I tried the toslink output and voila! --no more dropouts/pops. Now that I wasn't distracted/annoyed by the player, I compared it to my CD player (Onix CD 5SE) using the digital output into the same DAC. I would give the nod in sound quality by a slight margin to the SD card player.
However, up until last night I still had issues--I have three 8 GB cards loaded with music that would not play on this player. Two, four, and sixteen GB cards played fine, but the three 8 gig cards would not. Then, I noticed there was an 'updata04' version on the website yesterday, so I updated the player with this version, and again, voila! --The eight GB cards now work.
So, I am now pretty happy with the player (especially considering the price). I just received the switchable (3, 4.5, 6, 7.5, 9, 12 VDC) regulated power supply from Parts Express, and will give that a try tonight. If anyone is interested, I will update with any improvements this provides.
Regards;
limits
My DAC (TDA1543 single) is 5mm from the solder pads on the QA550 PCB.
Patrick
You beat me by a couple of mm...
So a bit of update :
This is a quick and dirty mock-up of a (part-of-a-Kitchen-Radio-System) SD player that we are going to turn the QA550 into. You can see how we rewired the dispaly, keyboard, remote, ....
At the I2S connections, a TDA1543 is directly soldered using a strip board. It has its own local 78L08, and a 10uF BG Std directly soldered onto the IC pins. IV is passive Riken 3k, and decoupling is just cheap 4.7uF WIMA MKS2.
Actually sounds great, better than it is entitled to.
The yet to be soldered PCB at the front is for a AK4396 version, with 2x LT1763 regulators, a DIY discrete regulator for DAC analog, Tent-XO on board, reclocking on BLK with 741G175, and direct out balanced using EPCOS 6.8uF MKP as decoupling cap. Probably Christmas. Too many projects.
Patrick
This is a quick and dirty mock-up of a (part-of-a-Kitchen-Radio-System) SD player that we are going to turn the QA550 into. You can see how we rewired the dispaly, keyboard, remote, ....
At the I2S connections, a TDA1543 is directly soldered using a strip board. It has its own local 78L08, and a 10uF BG Std directly soldered onto the IC pins. IV is passive Riken 3k, and decoupling is just cheap 4.7uF WIMA MKS2.
Actually sounds great, better than it is entitled to.
The yet to be soldered PCB at the front is for a AK4396 version, with 2x LT1763 regulators, a DIY discrete regulator for DAC analog, Tent-XO on board, reclocking on BLK with 741G175, and direct out balanced using EPCOS 6.8uF MKP as decoupling cap. Probably Christmas. Too many projects.
Patrick
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SD Card type problems
We tried some SD cards.
SanDisk Standard (1G & 2G) works fine, though the play sequence is not according to alphabetical order or original CD. According to Ckark Chen, it needs Firmware change.
We had bigger problems with SanDisk Ultra II which is more available than Standard for sizes >2GB in Europe at least. There we could not read at all, whether in FAT or FAT32. We cannot even use the Ultra II to upload Firmware in FAT32.
After some 6 or 7 emails, I finally managed to convince Mr. Chen that SanDisk Standard is not the same as Ultra II or Extreme III. He did promise to test and change Firmware to support (many thanks Mr. Chen), and I have sent him an Ultra II so that he can test with cards that we get in Europe, even though all SanDisk memories should in theory come from one source (that I know for certain but am not disclosing).
So for those in Europe, try only to buy SanDisk Standard (SDSDB) for now, until new firmware is confirmed to work with Ultra II.
Patrick
We tried some SD cards.
SanDisk Standard (1G & 2G) works fine, though the play sequence is not according to alphabetical order or original CD. According to Ckark Chen, it needs Firmware change.
We had bigger problems with SanDisk Ultra II which is more available than Standard for sizes >2GB in Europe at least. There we could not read at all, whether in FAT or FAT32. We cannot even use the Ultra II to upload Firmware in FAT32.
After some 6 or 7 emails, I finally managed to convince Mr. Chen that SanDisk Standard is not the same as Ultra II or Extreme III. He did promise to test and change Firmware to support (many thanks Mr. Chen), and I have sent him an Ultra II so that he can test with cards that we get in Europe, even though all SanDisk memories should in theory come from one source (that I know for certain but am not disclosing).
So for those in Europe, try only to buy SanDisk Standard (SDSDB) for now, until new firmware is confirmed to work with Ultra II.
Patrick
QA-550 is copy from koonlab website
Actually, this item is copy from Koon Lab and modified the remote control from himself. The author is created this item in 2006 if you download the schematic. WAV Player is using dsPIC33FJ64GP306 / dsPIC33FJ128GP706 and the total cost is under $20 for this.
So it is very expensive , if you can DIY from yourself and it will be VERY cheap.
Actually, this item is copy from Koon Lab and modified the remote control from himself. The author is created this item in 2006 if you download the schematic. WAV Player is using dsPIC33FJ64GP306 / dsPIC33FJ128GP706 and the total cost is under $20 for this.
So it is very expensive , if you can DIY from yourself and it will be VERY cheap.
Well, I did not pay USD100 for mine (promotion price), was too lazy to program the remote myself.
And to be fair, QLS updated the firmware for upgrade through SD card, FAT32 file handling, 32G SD, .......early this year,
before Koon did his version 2 only recently.
And if you count all the components on a well made PCB incl. SPDIF output, it is not too expensive.
He did not spare money on components.
Eventually I shall build the Koon Ultimate Source V2 (see his own thread), but I have something to play with in the meantime.
Patrick
PS I have no commercial interest, and am not trying to defend anyone. I just think one should be fair in making critical remarks.
And to be fair, QLS updated the firmware for upgrade through SD card, FAT32 file handling, 32G SD, .......early this year,
before Koon did his version 2 only recently.
And if you count all the components on a well made PCB incl. SPDIF output, it is not too expensive.
He did not spare money on components.
Eventually I shall build the Koon Ultimate Source V2 (see his own thread), but I have something to play with in the meantime.
Patrick
PS I have no commercial interest, and am not trying to defend anyone. I just think one should be fair in making critical remarks.
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