-40 is garbage TDA 1540, TDA1543
-45 is very bad
-50 is bad
-55 is mediocre TDA1541
-60 is good
-65 is very good
-67 is absolute maximum I found among PCM56
all relative to input signal
So K/Y ranges from bad to near very good,
and if more chips are beeing tested even more diverse results are found.
-45 is very bad
-50 is bad
-55 is mediocre TDA1541
-60 is good
-65 is very good
-67 is absolute maximum I found among PCM56
all relative to input signal
So K/Y ranges from bad to near very good,
and if more chips are beeing tested even more diverse results are found.
Well, my email to Juang aka A'af requesting that he send some extra chips for me to select some decent ones was met with a demand that I apologise on the forums for suggesting his products were FAKE. Given the body of evidence that these products are FAKE I feel that A'af is suggesting I make posts against what is clearly the actual situation so he can continue to profit from the diy community.
A'af has agreed to take the chips back and refund purchase price.
Looks like I'm back to running the PCM63K's for the moment...
Looks like I'm back to running the PCM63K's for the moment...
I once read that the kind of marking used on those Ys was introduced by BB to make it harder to re-mark expensive chips by amateur criminals.
IMHO it can't be proved wether the Ys are fakes or not.
In any case stamps are not worth the high prices paid for.
Better select chips and put on them your own stamp.
IMHO it can't be proved wether the Ys are fakes or not.
In any case stamps are not worth the high prices paid for.
Better select chips and put on them your own stamp.
Ongoing
Are you sending all "Y"s back or only exchanging / selecting some of them?
I remember you saying that if there have not been the all the discussion here about fake or not fake PCM63’s, you would have enjoyed the D1V3 + "Y" with no hesitations.
spzzzzkt said:
Are you sending all "Y"s back or only exchanging / selecting some of them?
I remember you saying that if there have not been the all the discussion here about fake or not fake PCM63’s, you would have enjoyed the D1V3 + "Y" with no hesitations.
A'af took offense to my comments earlier in the thread that you could not positively confirm his chips as genuine on the basis of the contents of this thread. Pretty reasonable but contrary to his assertion that this thread was proof his chips were genuine:
I would have preferred to exchange the not up to scratch chips and retain the good ones. However A'af stated I must publicly apologize for the above comments before he would even discuss this possibility. I'm not sure I would know what to apologize for? scaring off customers?
I proposed that he send me a 4 or 8 chips which I would test, pick two that matched the best two I have and return the rest with test results which he could use as he liked.. His response: "I owe you nothing." I guess I might of got further if I didn't hint at taking some kind of action if he didn't respond after he hadn't bothered to reply to my first email proposing a similar arrangement to replace the two chips that measure quite badly.
I definitely would not have bothered shelling out $250US plus shipping plus paypal fees if I'd know that these chips were only marginally better than the $25 a piece pcm63k which I bought initially knowing they were most likely of questionable origin.
I would have preferred to exchange the not up to scratch chips and retain the good ones. However A'af stated I must publicly apologize for the above comments before he would even discuss this possibility. I'm not sure I would know what to apologize for? scaring off customers?
I proposed that he send me a 4 or 8 chips which I would test, pick two that matched the best two I have and return the rest with test results which he could use as he liked.. His response: "I owe you nothing." I guess I might of got further if I didn't hint at taking some kind of action if he didn't respond after he hadn't bothered to reply to my first email proposing a similar arrangement to replace the two chips that measure quite badly.
I definitely would not have bothered shelling out $250US plus shipping plus paypal fees if I'd know that these chips were only marginally better than the $25 a piece pcm63k which I bought initially knowing they were most likely of questionable origin.
and yes I'm not sure if I will send them back - i'll see how I feel about it tomorrow. It just hurts having effectively paid $250 for two good chips. Genuine or not that is just stupid money for a pair of DAC chips.
as bernhard says it doesn't really matter if they are fakes or not. if they sound good they are good. What I see as the main issue with A'afs chips is that he's charging a premium price on the basis they are a high performance chip - but what you get is a "lucky dip". People _are_ getting bad sounding chips, b_d's experience shows and the tests I've done bear out there is bad and good. If you pay for a BMW you expect all BMW not half BMW with the rest Trabant.
cheers
Paul
as bernhard says it doesn't really matter if they are fakes or not. if they sound good they are good. What I see as the main issue with A'afs chips is that he's charging a premium price on the basis they are a high performance chip - but what you get is a "lucky dip". People _are_ getting bad sounding chips, b_d's experience shows and the tests I've done bear out there is bad and good. If you pay for a BMW you expect all BMW not half BMW with the rest Trabant.
cheers
Paul
My two cents:
Buy defective or working CD Player that contain PCM63, Pioneer PD8500 has them, take out the chips and the laser and a few nice caps maybe, throw away the rest.
You will have the same chance for good chips "lucky dip" plus genuine garantie plus burn-in already done by the previous owner(s).
That's how I do it.
I found one PCM63-K in my boxes, one leg has been repaired, should be used in a socket, date code 9227, fully working, measurement result unknown, I have no player for it to test at the moment. 10 EUR plus shipping.
Buy defective or working CD Player that contain PCM63, Pioneer PD8500 has them, take out the chips and the laser and a few nice caps maybe, throw away the rest.
You will have the same chance for good chips "lucky dip" plus genuine garantie plus burn-in already done by the previous owner(s).
That's how I do it.
I found one PCM63-K in my boxes, one leg has been repaired, should be used in a socket, date code 9227, fully working, measurement result unknown, I have no player for it to test at the moment. 10 EUR plus shipping.
Bernhard,
For those chips measure relatively no so good, can we get better by doing trimmer adjustment as per the datasheet?
Yes I also prefer to buy used chips which more likely to be good.
For those chips measure relatively no so good, can we get better by doing trimmer adjustment as per the datasheet?
Yes I also prefer to buy used chips which more likely to be good.
The adjustment of the PCM63 affects only near full scale, -6 to 0 dB.
For the 1000th time 😉 , this is why I use PCM56, it has MSB adjust for low level signals, that gets about 30 - 50% of chips to perform well.
Besides it has a smaller footprint which is important for paralleling chips, cost much less, is widely available in old CD players, allows large values of passive I/V resistors, performs very good at non os...
For the 1000th time 😉 , this is why I use PCM56, it has MSB adjust for low level signals, that gets about 30 - 50% of chips to perform well.
Besides it has a smaller footprint which is important for paralleling chips, cost much less, is widely available in old CD players, allows large values of passive I/V resistors, performs very good at non os...
Ongoing
Indeed, for this money you should get all 4 DAC chips in premium quality. There is no any doubt about this.
I am sorry that I was not aware to the fact that A'AF is not proofing his Chips before mailing them to the clients. I was sure that this just happened to me once (as I was the first one to buy them).
Moreover: A'AF wrote to me at the time that it never happened to him before that someone complains about the PCMs 🙂smash:
). BUT, he send me then some more Chips so I was able to match them; I felt that he trusted my judgment and that he was all in all OK. I simply sent him back the rest / what I didn't like, and that was it.
I got one pair of great “Y”s for about US$ 125.- but also a bit of nervous tension. A good friend took the other 2 matched pairs of “K”s (1 of them was from the same PCM63K “military grade” line which have been good as well).
I feel somehow sad about what happened to some members here. However, A’AF did replace the Chips and I hope that things will be at the end OK for everybody here. It would surely be very nice to hear from A’AF that he is going to exchange the bad “Y”s for you and beauty_devine with no hassle.
Paul, whatever you decide, please don’t send back the good sounding “Y”s. I trust your ears & measurements and I will gladly take them from you as a second pair / reserve for the future.
Conclusion: This should not be of a reason to consider going backwards to the “K” and surely not to the PCM 56 😉
Greetings,
IY
spzzzzkt said:
Indeed, for this money you should get all 4 DAC chips in premium quality. There is no any doubt about this.
I am sorry that I was not aware to the fact that A'AF is not proofing his Chips before mailing them to the clients. I was sure that this just happened to me once (as I was the first one to buy them).
Moreover: A'AF wrote to me at the time that it never happened to him before that someone complains about the PCMs 🙂smash:
). BUT, he send me then some more Chips so I was able to match them; I felt that he trusted my judgment and that he was all in all OK. I simply sent him back the rest / what I didn't like, and that was it. I got one pair of great “Y”s for about US$ 125.- but also a bit of nervous tension. A good friend took the other 2 matched pairs of “K”s (1 of them was from the same PCM63K “military grade” line which have been good as well).
I feel somehow sad about what happened to some members here. However, A’AF did replace the Chips and I hope that things will be at the end OK for everybody here. It would surely be very nice to hear from A’AF that he is going to exchange the bad “Y”s for you and beauty_devine with no hassle.
Paul, whatever you decide, please don’t send back the good sounding “Y”s. I trust your ears & measurements and I will gladly take them from you as a second pair / reserve for the future.
Conclusion: This should not be of a reason to consider going backwards to the “K” and surely not to the PCM 56 😉
Greetings,
IY
I don't think A'af does any quality control or checking - the "GB: for 2SK389 and 2SJ109" thread stands witness to that. But I guess the general perception is the Y grade must be better so people don't question that the performance will be good. Hopefully this thread has opened peoples eyes to the fact DAC grades don't guarantee good performance.
I've decided to hang onto the 2 better performing Y's as I doubt I'll easily find ones that measure this well. I will to talk with A'af one more time, to see if he is prepared to work something out to replace the chips that are clearly substandard.
I sincerely hope that A'af does decide to do grading on his chips if he continues to sell them at his current price. I guess he thought I was being a smart a**, but that was motivated me to offer him test data on the ones I sent back...
I've decided to hang onto the 2 better performing Y's as I doubt I'll easily find ones that measure this well. I will to talk with A'af one more time, to see if he is prepared to work something out to replace the chips that are clearly substandard.
I sincerely hope that A'af does decide to do grading on his chips if he continues to sell them at his current price. I guess he thought I was being a smart a**, but that was motivated me to offer him test data on the ones I sent back...
spzzzzkt said:
Hi spzzzzkt,
Did we are agreed offline about the statement above?
If you have change your mind, please mail me with the "nice" sound please 😀
Yes i know, those chips are premium price, so i will try to provide with premium service also 🙂
But no reply to your mail about 2 days and later mail me with tension and seems i want to run.... not my style....
and about overstating... if FAKES sound more better than excellent... so the result is a GREAT FAKES!!
from the first start i know this not a fakes, even IY know first!! (actually 😎 ) but yes i didnt realize some of those have a bad performance. How do i say, i dont have times to test them one by one for sure...
okay wanna hear from you in this first of May...
all the best,
a'af
Only wanted to confirm again the finds of Bernhard and Paul.
After having redone the test shown earlier, with better resolution and more averaging, the pic got much clearer, and the spurs much more visible. And the best testing chips in my posession are the noname nostamp BBkorea ones from '98.. and the level differences are the same that had been shown.
A sidenote: if You think less spurs are the king, then try dithering:
my Rotel player measured so well because the dither was on, at level 7. [PMD100] This also forces somehow both channels more uniform.
Here it is again, dither level 7, and both channels looking like this:
(carrier level is -60db on the disc but measures like -65db here.)
After having redone the test shown earlier, with better resolution and more averaging, the pic got much clearer, and the spurs much more visible. And the best testing chips in my posession are the noname nostamp BBkorea ones from '98.. and the level differences are the same that had been shown.
A sidenote: if You think less spurs are the king, then try dithering:
my Rotel player measured so well because the dither was on, at level 7. [PMD100] This also forces somehow both channels more uniform.
Here it is again, dither level 7, and both channels looking like this:
(carrier level is -60db on the disc but measures like -65db here.)
Attachments
Also dither level 4 is similarly good.
Question to Paul: did You find a correlation between the sound and measurement level? I don't know, I would need more time to concentrate on it, but for me the better measuring korean chips did not sound better in the Dac, [apart from sounding horrible for the first couple hours.. though this had passed away later on]
Other point: Remember that PCM58 measured so bad earlier?
Here it is, before MSB adjustment: [actually there are only two pots implemented out of 4 for most upper bits]
Question to Paul: did You find a correlation between the sound and measurement level? I don't know, I would need more time to concentrate on it, but for me the better measuring korean chips did not sound better in the Dac, [apart from sounding horrible for the first couple hours.. though this had passed away later on]
Other point: Remember that PCM58 measured so bad earlier?
Here it is, before MSB adjustment: [actually there are only two pots implemented out of 4 for most upper bits]
Attachments
And after adjustment [and it's still only a first approach, only bit 18 bit 17 adjusted, should go on with bit16 bit15]
(Carrier is -63dB with this player, and notice also the ~10db lower noise in the floor, the spikes still visible here would be in the noise in the previous pic)
(Carrier is -63dB with this player, and notice also the ~10db lower noise in the floor, the spikes still visible here would be in the noise in the previous pic)
Attachments
A friendly msg. to A'AF (Juang)
A'AF, a real friendly advice to you, and please allow me:
Try and find some method to proof things like the PCMs (“K" or "Y") before mailing them. It might not be an easy thing to do, but you will be the first to benefit from it. People here generally like your merchandise & working with you, but you also have a big responsibility towards all of us, especially as we are working in such a tricky and difficult subject as sound.
When you originally told me that there are no problems known to you with the PCMs, I felt quite embarrassed to tell you that “you are wrong”, especially as a novice on this board. Of course, I did not have any other choice as to trust my own ears, and they told me a simple answer which you also accepted. I appreciate your readiness to send me some other chips, a fact which enabled me to have what I truly enjoy nowadays, this excellent sound.
But it is exactly this topic of integrity which you should protect by all means, simply by keeping supplying your clients with the best possible products, while finding a way to pre test them before shipment.
All the best,
IY
A'af said:
A'AF, a real friendly advice to you, and please allow me:
Try and find some method to proof things like the PCMs (“K" or "Y") before mailing them. It might not be an easy thing to do, but you will be the first to benefit from it. People here generally like your merchandise & working with you, but you also have a big responsibility towards all of us, especially as we are working in such a tricky and difficult subject as sound.
When you originally told me that there are no problems known to you with the PCMs, I felt quite embarrassed to tell you that “you are wrong”, especially as a novice on this board. Of course, I did not have any other choice as to trust my own ears, and they told me a simple answer which you also accepted. I appreciate your readiness to send me some other chips, a fact which enabled me to have what I truly enjoy nowadays, this excellent sound.
But it is exactly this topic of integrity which you should protect by all means, simply by keeping supplying your clients with the best possible products, while finding a way to pre test them before shipment.
All the best,
IY
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