I am very very interested in the claims that the AK240 can play DSD native files, but I couldn't understand how it can possibly do it. After looking at the specifications of the DAC's they are using it didn't make sense to me.  I wrote the following email to the company. 
 
My Original Email:
 
Hello,
 
I hoping you can please explain something to me before I place my order for the Astell & Kern AK240.
 
The unit is using 2 DAC chips with a max sample rate of 200KHz. How is the unit getting DSD Native : DSD64 (1bit 2.8MHz), Stereo / DSD128 (1bit 5.6MHz), Stereo? Isn’t 5.6MHz 5600KHz, so how is the unit getting 5600KHz out of a DAC who’s maximum sample rate is 200KHz. Is the unit downgrading the 5600KHz signal to get it to output at the 200KHz rate.
 
Thanks for your time
 
This was there first reply:
 
Dear iriver customer,
 
Thank you for contacting iriver customer support. 
 
To better assist you, please provide us with a link of where you found information on the sample rate of 200kHz. If you have any questions or concerns please email us back at any time.
 
Thanks & Regards,
 
iriver Inc.
CS & Tech Support
949-336-4540/1
shop.iriverinc.com
 
This was my reply:
 
Here is where I saw the 200KHz rate. Third paragraph.
 
http://www.cirrus.com/en/products/cs4398.html
 
Looking forward to hearing back from you
 
This was there reply:
 
Dear iriver customer,
 
Thank you for the link. We will forward this message to our engineering team for an answer and get back to you on it when we get a response from them. If you have any questions or concerns please email us back at any time.
 
Thanks & Regards,
 
 
After a few days of no reply, I sent them another email asking if they had an answer for me. This was there reply:
 
Dear iriver customer,
 
Thank you for contacting iriver customer support. 
 
We received a response from our engineering team regarding your inquiry. There is no downgrading of any signal. Our own technological setup allows for the unit to produce 5.6 MHz. If you have any questions or concerns please email us back at any time.
 
 
My thoughts:
 
I still don't understand how this is possible based on the specification of the DAC's being used. If anyone could explain this to me I would greatly appreciate it. 
 
 
 
 
 
 
 
 
 
 
 
 
 

I have not heard anything back from anyone.

Post this on the AK240 thread.

That's PCM sample rate. Even at that, the effective frequency would be defined as 216 khz x 24 bit so 8.9mhz of 1bit capability could be present and possibly higher due to oversampling and configuration. The DSD has a different input path so the PCM specs are not that relevant to DSD operation anyway.

Thanks goodvibes

I finally got a response from iRiver:

Dear iriver customer,

Thank you for contacting iriver customer support.

5.6 MHz is possible due to the use of our exclusive DAC chip together with the dual Cirrus DAC within the unit. If you have any questions or concerns please email us back at any time.

Thanks & Regards,

iriver Inc.
CS & Tech Support
949-336-4540/1
shop.iriverinc.com

So they use two DAC chips and an exclusive processor chip to achieve this...