The "K" Grade PCM56 DAC Upgrade

Continue from the previous post about PCM56P-J here, I should admit that chasing the highest grade for this DAC IC is just like playing a fun game. Early disclaimer for this grading is actually made and measured by the Burr-brown manufacture to differentiate the measurement result after the IC's come out from the production lines. The closest to the best THD specification will be stamped by "K", the lesser THD number will be the "J" stamped and the last is no grade. Fun fact about this THD number can also be optimized, depends on the application use. Other than that, as stated in the datasheet, most of this R2R DAC IC's made by Burr-brown can be do the MSB adjust, so the THD number can be much better after this adjustment.

So, what this grades marking are for? Is it only for marketing purpose? Well, short answer it is not. Without or with MSB adjust, the final THD number can be better if the original IC having advantage from the lowest THD number. Other than that, the reason for this grading is because the MSB adjust taking another process in audio manufacture which require more time and measurement. So out of the box, Burr-brown R2R DAC IC using grades to determined THD performance without any MSB adjust. This is become more easy for the audio manufacture put their product based on the specification requirement.

Just like in my DAC, I don't use this MSB adjust feature. Simply because I don't have the measurement tools for this adjustment.

As my previous finding, the difference between PCM56P to PCM56P-J is subtle. Although the detail and sound imaging are more reveal with the "J" grade but overall it is quite impressive in my opinion, by changing the DAC IC with different grades only.

So, last week I got offer from my friend who had the PCM56P-K dismantled from vintage CD player. It is hard to say no.

I bought 2 pair of this PCM56P-K. Strange for the "K" marked on each pair of the IC are different to another. One pair having "K" in bold, the other pair having "K" with dot. But for sure they are all original DAC IC.

Once I finished with those easy swap, I immediate test this "K" grade DAC.

I could tell that this PCM56P-K have no difference with previous PCM-56P-J. I couldn't spot the improvement or the degrade of the sound quality at all. It is the same great sound performance as before. This could be my brain cannot telling the difference if the THD number are already both low.

This finding not really a disappointment for me. I know from the first time I chasing to this better grade DAC IC is a just like playing a hunting game. The journey to having this highest grades give me more enjoyment than the result itself.

I will keep it all for sure.

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