16 bit vs 24 bit vs 35 bit vs 36 bit vs 64 bit DAC sampling

I have limited knowledge about DAC's, but as I understand it, a typical CD player used to have 16 bit sampling, and supposedly no one was supposed to be able to hear the difference between anything more than 16 bit sampling; however, I recently purchased an Esoteric K-01X, which has 35 bit sampling (why 35 bits? no doubt only to differentiate it from their then top of the line 36 bit sampled Grandioso series).  

Now I can hear a big difference between my old Musical Fidelity kW DM25 DAC with 24 bit sampling (circa 2005), and the newer Esoteric DAC with 35 bit sampling, although I'm not supposed to, although maybe there are some other electrical programs playing with the sound besides the sampling rate.  

Now, there are 64 bit sampling DAC's, and I'm wondering how much the ear actually does hear from the sampling, or if it's something else entirely that's making the digital sound better?  

Any insightful opinions or perspectives?  


If 20 bits is all that is possible, why are the engineers chasing the bit rate higher to 64 bit rate now?  I suppose there's alot of people who don't understand what they are doing with the bit rate?  Maybe this is this akin to selling the $4,000 XLR cable when the $60 cable is as accurate as you'll get. . . 

So it's the other features of the unit that make it sound so much better?  I suppose it's the transport, the power supply, the more accurate clock, the high slew rate, large current, and digital filters that are playing the larger role of improving the sound quality.   

Here is the ad from the Esoteric K-01X features page:

35 bit D/A Processing

The K-01X combines multiple 32-bit DAC chipsets and utilizes 35-bit D/A processing algorithm to convert the PCM signal to analog at a high resolution in excess of 32 bits. 35-bit processing achieves an astounding resolution that is fully 2,048 times that of 24-bit processing. In the digital range, full advantage is taken of high-bit data gradation to minimize calculation errors and provide faithful conversion to analog, thereby attaining outstanding powers of expression with even extremely small music signals.

Read this about digital 20 true bits is all that is currently possible 
Ben at Mojo Audio knows his digital and builds a very good dac .
Whatever you're hearing, it's not the bit depth.  If indeed you have a 35 bit DAC, which I doubt (regardless of manufacturers claims), I guarantee the bottom 20 bits are lost in the room noise.
The Esoteric ad copy is classic.
"In excess of 32 bits," immediately specified to 35 bits.
"fully 2,048 times resolution" because 2**(35-24) = 2048. The "fully" is laughable; do other vendors stop at 2000 times?
"attaining outstanding powers of expression" - good Latinate pomposity.

"attaining outstanding powers of expression" - good Latinate pomposity.
+1. That's marketing, not engineering.