Esoteric K-01X or K-03X??

I just sold my 6 years old Esoteric X-03SE CD player and 2 years old G-03X Master Clock today. So it’s time for me to decide which is my next CDP: Esoteric K-01X or K-03X?

 I have a friend who bought a K-01X four months ago, he listen to it about 2 months but not happy with the sound (He said not musical and lack of emotion…), then he put it into the box and continue enjoy his Vinyl. Because of our close relationship and this guy is rich, I can get his K-01X around USD 9400 only. If I buy a brand new K-03X, I pay around USD 7500. I know this is a very good deal, and I know many of you will say just go to get this K-01X. Yes, I saw hundred of posts about the good thing of K-01X, but I never have chance to compare it side by side with K-03X. Does K-01X really sound much better than K-03X? 

I’m thinking if we can use quantization to measure these CDP, if you give K-01X 100 scores, then score you give K-03X? 95? 90? 85? ....

So what about compare to K-03X and the my old X-03SE? If you give K-03X 100 scores, then what score you give X-03SE?

I’m thinking maybe I can save some money to buy other things like a 4K color new TV if I choose K-=03X. BTW, I’m not interested in CAS, so DSD has no meaning to me. I just use my CDP to pay my normal Red Book audio CD and SACD. Thanks a lot and have a nice weekend!

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I have the KO3x and like it a lot. I have heard the KO1x it is the better player of the two. I just could not swing the price of the KO1x.  If you give the KO1x a score of 100 then i feel the KO3x would be 93-94 score. Both players have multi settings(filters) and up sample rates which effect the sound. Each filter and sample rate have a very long break in time. If your friend did not break in the filter and sample rate or kept changing the filter or sample rate a round before it settled in it would sound dry or with out emotion. Of course the other components a  long with cabling and interconnects effect the sound as well. If you can get the KO1x for$9400.00 and it only has a few months on it i would buy it. Your KO3x new at $7500.00 is a good price too, i payed more for mine new. I would ask your friend to let you demo the KO1x for a while and see how it sound in your system. Just remember break in is long.
enjoy Pete
That’s a VG price for a K-01X. I doubt that your friend’s unit is nearly broken in. It took 1000+ hours for mine to come fully on song; after break-in it compares favorably to vinyl. If you do buy it, sell the G-03X clock and purchase a Stanford Research PERF-10. This has the same Rubidium core as the Esoteric G-01.

These are what's inside both, pick your poison.

ESOTERIC K-01 8 x AK4399EQ

VRDS-NEO VMK-3.5-20S- SPU3162

ESOTERIC K-03 4 x AK4399EQ

VRDS-NEO VMK-3.5-10 – SPU3162

If your only doing Redbook I would say neither, as they both use Delta Sigma dacs (AK4399EQ), and for "bit perfect" Redbook conversion a R2R ladder Multibit dac is the way to go.

But seeing you want to do sacd as well, then I would choose the K-01 as it uses 8 x AK's and they did that for a reason. 

Cheers George

R2R is not the magic, NOS is the magic, and the AKM DAC can do it. But with that said, just get the TEAC UD-503. There is no need to spend lots of money for DAC nowadays, the new tech is awesome and cheap. In fact, expensive DAC tends to be snakeoils.

Thanks for everybody's input!


Hi 68pete

If I’m correct, these new Esoteric CDP’s different multi settings (filters) and up sample rates is only for playing music file for CAS (Example: DSD)? Amy I correct?

However, my friend only use it to play audio CD and SACD, so it shouldn’t related to multi filters and up sample rates.


Hi dgarretson

I think even my friend just use it for less than 200 hours, the sound should not lack of musical and dry. So what I’m thinking is my friends’ equipment like amp, speaker and cable does not match with his K-01X.


And sorry I missed one information, this K-01X is not a 220V CDP  (My location is using 220 to 230V), which is a Japanese version 120V product. The seller convert it to 220V by setting the internal jumper, so I’m not sure if this will change the sound quality a lot??

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I cannot compare the two, but Esoteric players have a reputation for needing way more than 200 hours to sound good...

The selectable upsampling and filtering options apply to both RBCD and SACD from the transport.  My opinion of these options has evolved through the break-in process. After extended break-in is I gravitate toward RBCD upsampled to unfiltered DSD and SACD unfiltered.  However the 10Mhz Rubidium clock makes more of a difference than the upsampling and filtering options.

BTW, the K-01X is sensitive to PCs and platforms.  Hopefully your friend played around with the ancillaries before forming critical judgment.  I'm using a Starsound Sistrum Rhythm rack and a DIY shielded PC with 10awg silver conductors.

A well broken-in K-01X is big, bold, and emotionally involving.

Hi mmb1622
The up sampling rates and filters do apply to cd play back as well as sacd play back. You want to make sure its a KO1x and not a KO1 they are different. Same with a KO3x and a KO3. the "X" is a upgrade in chip and build. I am pretty sure the older KO1 can get a "X" up grade, but it is not the same as a original factory KO1x same with the older KO3. Best to check with Esoteric.
Enjoy Pete

R2R multibit is the magic, for "bit perfect" Redbook replay, as Delta Sigma (bitstream) is just a facsimile (approximation) of PCM conversion process.

You just have to take a look what the latest high end flagship dac’s like MSB, Trinity, AMR, Schitt, and many others are going back to R2R ladder now to get Redbook right.

But the OP wants to be able to do SACD as well, so he’s stuck using Delta Sigma conversion, even though it’s a step down from R2R for Redbook conversion.

Cheers George

Thanks! Seem like the up-sampling rates and filters are very interesting thing to try. May I know is that mean different up sampling rates and filters produce different sound character? For example:


Up Sample-1 = Very clear, very high analytical and transparency sound

Up Sample-2 = Rich, more thicker and transparency sound

Up Sample-3 = Between sample 1 & 2

Am I correct?

About the Stanford Research PERF-10 : 10 MHz rubidium audio clock. As I know many 10M rubidium Clock/ Oscillator need to work with an external master clock like Esoteric G-03X, G-02 or G-02. But according to dgarretson, it seem like Stanford Research PERF-10 can WORK with K-03X/ 01X directly and without necessary an external master clock, am I correct?

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Just look at the Stanford Research PERF-10 information, it don’t have any setting of the frequency (Which mean to the tell the CDP what frequency to use: 44.1 kHz or 48 kHz”, so I think it still need an external master clock with work with it. Unfortunately I just sold my Esoteric G-03X……..This is another big investment to buy a G-02 and a Stanford Research PERF-10………

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I agree with the posters above; grab the K-01X at that unbelievably good price and then carefully put 350 hours (at least) on every filter combination as well as ensuring you put the same on CD as well as SACD playback. The results are worth it in the long run but know that you are looking at 1500-2000 aggregate to do it properly. As noted above the filters and up-sampling choices figure into all aspects of CD and SACD playback.  That stated, there are other threads here where myself and many others have tested and commented; I prefer 176.4 up-sampling with the S_DLY2 filter options for the K-01 and X versions as well as my P-02/D-02.

Power cord and interconnect choices are also very important.   So is the choice of using the balanced XLR outputs to get the best sound out of any Esoteric unit....

Good luck with your decision...the K-01X followed by methodical break-in and finding the right combinations for your listening preferences is definitely the way to go!
The 22Mhz master clock in the K-01X synchronizes to the PERF-10 at 10Mhz, and all other frequencies are derived within the CDP.You don't need a G-02.  If you purchase a Perf-10, get it with the optional 12Vdc power port for use with an outboard linear PS.

maybe when your friend realizes he has not yet heard what his Esoteric is capable of, he will no longer want to sell, and you won't have a decision to make...
"The 22Mhz master clock in the K-01X synchronizes to the PERF-10 at 10Mhz, and all other frequencies are derived within the CDP.You don't need a G-02. If you purchase a Perf-10, get it with the optional 12Vdc power port for use with an outboard linear PS."

Absolutely agree...the PERF10 is a true 10hz atomic master clock; the master clock in the K-01X (or the D-02, etc...) will use it as a reference and then derive even more accurate clock sync operation as a result.  

Are both players excellent for CD and SACD?
One better than the other on SACD playback?

Because my friend’s K-01X don’t have any warranty service, but a brand new K-03X is include one year free warranty service.  And I can get t at around USD 7080 after negotiate, so finally I order K-03X and I will receive it this Thursday.

After I order my new CDP, I saw a pair of beautiful, excellent condition’s used walnut burl Avalon Opus Ceramique speaker in a 2nd hand audio shop. I always dreaming to own a pair of maple burl or walnut burl Indra for long time, but I cannot afford Indra. I’m also thinking to upgrade my Ascendant II if I can get a good condition Opus. So this is my destiny to meet this pair of speaker. Immediately I test it, I love the sound and then I use my Ascendant II, add some money to trade in this pair of Opus. A new CDP and a pair of speaker is a big investment for me, I got to be careful when using money in the near future….

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Hi  mmb1622
If your Esoteric K-o3x is brand new from a dealer, if you register with Esoteric they give you 2 more years of warranty for a total of 3 years. Its a very nice unit, just remember that break in is long.
enjoy Pete 

Hi 68pete

Unfortunately, only one year warranty service in my region provided by the dealer. And this is one of the reason why the price is cheaper than normal market price.

I'm using my K-03X about one week, it sound very nice, and I agreed it sound better than my perviou X-03SE, better texture, better 3D dimension, wider soundstage, more smooth like silk. I hope I have enough money to buy K-01X.

The only disappointed for me is I try 8 different up-conversation, PCM and DSDF setting for my CD playback, but seem like the difference is very small with original setting. Does someone has similar experience 
What filter setting are you using?  Did you try 176.4 upconversion with SDLY2 or SDLY1 filter?


I also tried original, 2Fx, 4fs and 8Fs in Up-conversion setting, but all sounds very similar to my ear (perhaps I have bad ears……), so I just pickup a combination that sound nice and more noticeable for me, which is:

Up-conversion = DSD



BTW, how can you choose 176.4kHz in 8Fs? It seem like you can’t choose the kHZ (?)

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i believe 176.4 is limited to 4FS. One thing you may be experiencing is that you need to burn in every combination of settings for both RBCD playback as well as SACD.  Things will not sound their best until you do with the K01, K03, 02 or 01 separates....
Where are you located mmbl622 ?


I'm in Kong Hong.

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I have a K03 and would KILL for that K01.  They need over a thousand hours of break in so could be the current owner never gave it enough time to open up.  GRAB IT!
On a newly released k1x, who cares about 1 year warranty.  Your friend can help you if that issue arises anyway.

i would've said you made a bad move going k3x
Sorry guys but 1000 hours to break up? How in normal condition  (4 hours playing  per day) do it ? Of course I may turn on the CD for a month but it is safe for the mechanism/ transport?
And the question is whether it is worth it
I consieder this CD but...
You just put the CDP on repeat and mute the preamp.  The mechanism is bulletproof.  Yes, you need to do it.