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RWAK100 - iriver AK100 mod by RWA

post #1 of 51
Thread Starter 

RWAK100 is a RWA modded AK100 like his famous iMod. I was provided a demo unit from him.

As for the details of RWAK100 include order instruction, have a look here.
http://www.audiocircle.com/index.php?PHPSESSID=aob5s3i1hrfv08r497pe9djcs6&topic=113484.0

 

 

* background

 

I am a big fan of his iMod, I have iMod 4G as well as iMod 5.5G. iMod 4G turned the headphone out to line out jack. iMod 5.G is still my favorite work horse of portable gear. I love its smooth and warm musicality even I compared it with iPod classic that I usually use for HP-P1 digital setup. Even if I have iPod classic now, I use iMod 5.5G for almost portable amp setup.

 

iriver AK100 is a new star of hires DAP world. I use it since I was involved in the pre-production testing audition. AK100 is a little marvelous DAP that delivers a detailed  hires sound up to 192kHz. AK100 is a good sounding gear even if I use it as stock condition, some people noticed on high output impedance may harm sound when coupled with low impedance IEMs.
Vinnie probably thought his method of the iMod would be a solution.

Here is the detail of the RWAK100 from his write up.


We bypass the 22-ohm resistors in the output stage, and hard-wire (via Cardas copper litz solid core wire) from the output stage FETs directly to the pins of the headphone output jack. Besides bypassing the 22 output resistors, this also provides the shortest, cleanest path from the output stage to the headphone jack - also bypassing the tiny circuit board traces, and the header that connects the main board to the smaller headphone jack board. It's essentially a direct connection from output stage to the headphone jack. Output impedance is now under 1 ohm...
 

The point of RWAK100 mod is to improve headphone out quality. Other parts are not modified at all so we can still use optic out and software upgrade. In addition, you can get decent fixed audio output thru headphone out by turn the volume all way up (max - 75). Doing so, you can bypassing the digital volume function. I guess it is an internal function of WM8740 DAC chip. This is same to stock AK100 by the way.

 

* impression

 

The box package and outlook is exactly the same to stock AK100 expect the base sticker shows RWA mod.

 

 


I have upgraded the FW with the latest 1.30 to compare with my stock AK100.
I use UE18 and JH16 mainly that has been combined with Whiplash TWag. Because I think UE18(21 ohm) and JH16(18 ohm) are low-impedance, high-efficiency and best performance to be able to reveal the difference.

 

 

 

The difference between stock AK100 and RWAK100 is obvious than I thought. Off course I hear the sound characteristic of AK100 is inherited but the overall sound impression has changed. The most notable change is the bass region. If you use Pops or Rock with a good bass beats, you will hear the huge difference there. The bass quantity is plenty compared with the stock and the bass is now impactful. I'd say the bass is impactful rather than to say bass is huge. The bass improvement affects on the whole audio spectrum and I feel the overall sound is now richer than the stock.
To feel the sound richer, I think more detail has also been contributed. Yes I found now RWAK100 is even more detailed than the stock. Even if I tried with acoustic instruments track, the difference is there. I can hear a slight guitar fret noise clearer.


With this bass and detail improvement, I enjoyed orchestral sound much better than before. I feel classical tracks more impressive  with RWAK100.

I also tried a sample track comes with the iriver microSD. For example "Spanish Harlem", bass impact is a big difference with RWAK100. The bass has more weight and attack. The detail of the hires track has more resolution in RWAK100. I hear more details thee.

 

Iriver stated Vinnie's mod would "Even it improves the sound power, it reduces smooth and delicate sound detail of AK100".
But I disagree with them. From what I found in the audition, I hear clear detail difference between RWAK100 and stock, that is RWAK100 is better regarding the detail and smoothness. iriver's objection could be theoretically correct I am not sure about it but the actual implementation on the tweak of RWAK100 - like shortest signal path, good cable - would enhance the sonic performance I guess.

 

As for headphones, I tried with Audio Techinica ESW10JPN(45ohm). Again RWAK100 delivers more bass with deep impact compared to the stock. This is not only for rock or pops, Even in the "Spanish Harlem" I hear the overall sound difference.

 

I also tried using ultra high impedance Heir Tzar 350(350 ohm). I noticed the bass difference is not huge now but I still found detail difference. When I took a listen with "Spanish Harlem", I hear more transparency in the details.

 

I was wondering about the bass characteristic of AK100 that is the bass seems inferior in custom IEMs but the bass seems enough with Tzar 350. Now the riddle has solved and the solution is here. Also the details are even better. I'd say RWAK100 would bring out the best of AK100.

post #2 of 51

Thanks for the comparison review Sasaki!!! Nice job,... beerchug.gif

post #3 of 51
Great review Sasaki-san! I'm very happy with my RWAK100 & although I did compare with the standard AK100 at Yodobashi, your review is a much needed thorough comparison between the two.

What was interesting was I let e-earphone try the RWAK100 & they felt it was too powerful for IEMs, which was contrary to my opinion.

The RWAK100 is supposedly 6dB more than the AK100 volume for volume. Could you please confirm if this is true?
post #4 of 51
Quote:
Originally Posted by AnakChan View Post

Great review Sasaki-san! I'm very happy with my RWAK100 & although I did compare with the standard AK100 at Yodobashi, your review is a much needed thorough comparison between the two.

What was interesting was I let e-earphone try the RWAK100 & they felt it was too powerful for IEMs, which was contrary to my opinion.

The RWAK100 is supposedly 6dB more than the AK100 volume for volume. Could you please confirm if this is true?

Hi Sean 

 

this is true that RWA  AK 100 sound about 5 - 6 dB Lauder than AK 100 stock .

 

until now about 1 week since he got his RWA AK 100 , my friend said his RWA AK 100 

 

still can not get the clarity and detail as AK 100 stock .

 

maybe he need some more burn in . 

post #5 of 51

Great  review Sasaki San as always I like to read your honest review beerchug.gif

post #6 of 51
Quote:
Originally Posted by rudi0504 View Post

Hi Sean 

 

this is true that RWA  AK 100 sound about 5 - 6 dB Lauder than AK 100 stock .

 

until now about 1 week since he got his RWA AK 100 , my friend said his RWA AK 100 

 

still can not get the clarity and detail as AK 100 stock .

 

maybe he need some more burn in . 

 

I find this very weird. Anyway, although I only compared the AK and RWAK for 10-15 mins, for that little time I spent I'd concur what Sasaki wrote above. His is obviously a much more detailed and thorough comparison.

post #7 of 51
Quote:
Originally Posted by AnakChan View Post

 

I find this very weird. Anyway, although I only compared the AK and RWAK for 10-15 mins, for that little time I spent I'd concur what Sasaki wrote above. His is obviously a much more detailed and thorough comparison.

Yes me to Sean , wait until next Saturday mini Meet, i will post his update here .

i guess he needs some more burn in time 

post #8 of 51
Thread Starter 

Hi all, thank you for the comments!

Sean, yes I hear RWAK100 sounded louder with my UE18.

post #9 of 51

Dear Sasaki san,

 

Thank you for posting your impressions!

 

All,

 

Regarding the RWAK100 being louder, the amount of total dB increase (increase in headroom) vs. the stock AK100 depends on the impedance of your headphones or IEMs.

 

For example, if you had 22-ohm headphones, then by bypassing the stock 22-ohm resistors, the output voltage is close to double, or 6dB more max output.

 

If your headphones are 120-ohm in comparison, then bypassing the stock 22-ohm resistors allows the max voltage output to the headphones to be 1.5dB more.  

 

But even though in the case of a 120-ohm headphone the max output voltage only increases by 1.5dB, you are getting better sound due to the much lower output impedance (22 ohm vs.

less than 1-ohm).  Much better damping factor, a flatter output response with the headphones (as the drivers are not resistors - it is more complicated than that because we are dealing with impedance, not resistance only, and there is also the headphone cable in series between the output stage and the headphone drivers), etc.  Don't want to make this very complex, but just like any good portable headphone amp, the lower output impedance is a good thing, and I'm glad Sasaki san was able to easy hear why in his evaluation. cool.gif

 

Cheers!

 

Vinnie

Reply
post #10 of 51
Great review smily_headphones1.gif really loving the RWAK100...
post #11 of 51
Hi everybody

I'm new here, this is my first post. Have UE18 and looking for a great DAP to go with it. Tried AK100 vs Colorfly C4 twith various WAV files in a store this week. Liked SQ of C4 more. Wondering if RWAK100 is closer to C4 with my UE18, or even on same level? Would much appreciate any comments on that. Maybe somebody has C4 and RWAK100 and can do a comparison?
post #12 of 51

Sorry to resurrect this thread but I'm seriously considering moving to a TOTL dap rather than a iPod stack (DAC/AMP). Can anyone comment on how this dap sounds in comparison to:

 

ipod+solo+Rx mk2/3

ipod+hpp1+Rx mk2/3

 

or 

 

ibasso DX100

HM-801

C4

 

Thanks for any help!

post #13 of 51
Quote:
Originally Posted by Greed View Post

Sorry to resurrect this thread but I'm seriously considering moving to a TOTL dap rather than a iPod stack (DAC/AMP). Can anyone comment on how this dap sounds in comparison to:

 

ipod+solo+Rx mk2/3

ipod+hpp1+Rx mk2/3

 

or 

 

ibasso DX100

HM-801

C4

 

Thanks for any help!

Quite a lot of info & comparisons in this thread: http://www.head-fi.org/t/630288/the-new-iriver-ak100-a-high-end-dap

post #14 of 51
Quote:
Originally Posted by dynamiteguitar View Post

Hi everybody

I'm new here, this is my first post. Have UE18 and looking for a great DAP to go with it. Tried AK100 vs Colorfly C4 twith various WAV files in a store this week. Liked SQ of C4 more. Wondering if RWAK100 is closer to C4 with my UE18, or even on same level? Would much appreciate any comments on that. Maybe somebody has C4 and RWAK100 and can do a comparison?

RWAK100 would be closer to the C4 but compared to the C4 the RWAK won't reach that level of awesome.

post #15 of 51

dos the mod player works with two 64GB micro SD cards?

 

and how can i get it?

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