Guys... you may want to hold off on modding your AK100's. I asked iRiver about the main concerns and received some positive answers to each question especially for early purchasers if firmware doesn't fix impedance issue. Here's my Q&As:
Dear iriver customer,
Thank you for contacting iriver customer support.
We are glad to hear that you are happy with the A&K. Here are our responses to your questions:
1. You must add gapless playback support. Many of my files are of live albums and the gaps are very annoying... There is a fair amount of discussion on this topic on Head-Fi.
We will contact our development team to assess this issue and get back to you.
2. You must be aware of the severe criticisms on the long AK100 thread on Head-Fi Forums of the high output impedance causing unnatural variations in IEM outputs. I have several high quality IEMs eg Westone 4R, Shure SE535s and so on. The W4Rs seem okay, but the Shures are definitely prone to higher and variable high frequency levels especially over about 3kHz. I don't get the same issue when running with an amp via optical signal. I have a pair of UE TripleFi 10 Pros and they are severely hampered by this output level. As I purchased the AK100 as a portable player, and live in a warm climate, I just don't want to use high impedance full size headphones nor spend money on new high impedance IEMs when I already have expensive and well regarded earphones.
This is a known issue and we are currently working on solving it. We will let you know when a fix has been made.
2.1 Do you intend to do anything about this issue?
As we have already stated above, it is a known issue and we are currently working on solving it.
2.2 Will you be able to do anything via firmware to correct this (I suspect it is hardware related).
Most likely the issue will be resolved by a firmware update. Please be patient while a new firmware is being created.
2.3 If not by firmware, will I be able to get a replacement unit under warranty/recall?
As long as you are within the US, or you provide us with a US mailing address, we should be able to provide you with a replacement unit if need be. Unfortunately we do not ship internationally outside US.
3. I am of the belief that iRiver is working on adding Alac and AAC support. How far of is this?
This is also currently being worked on but we do not have an estimated time of when it will be resolved.
If you have any further questions or concerns, please email us back at any time.
Thanks & Regards,
[size=9.0pt]iriver[/size]
[size=8.0pt]Customer & Tech Support[/size]