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-   -   AKM 4393 vs. AKM 4396 why bother? (http://www.diyaudio.com/forums/digital-line-level/160443-akm-4393-vs-akm-4396-why-bother.html)

nonsub 2nd February 2010 12:35 AM

AKM 4393 vs. AKM 4396 why bother?
 
Reading through the specs these appear to be the same with the following:

a) 4396 can sample up to 192khz whereas 4393 is 96khz. In an application for example trying to mod a dcx with this chip, I believe supports only a max of 96khz anyway?

b) Potential problem is the 4396 output is 2.8v/5.6v whereas 4393 is 2.4v/4.8v

c) 4396 sports a linear 256 step digital attenutation, has anyone interfaced to this?

So the question is why bother modding and how are people claiming improved performance (other than louder due to voltage LOL)

data 2nd February 2010 02:01 AM

The AK4396 has an incredibly quiet background.

That what I remember reading somewhere...

Here it is, was from someone at AKM.
AudiogoN Forums: Hi-fi Wi-fi device

Cut&Past:
07-26-06: rkulavik@akm.com
AKM is the worlds largest DAC Supplier, this I would add does not make you the best. However,the part Alex is talking about is the AK4396 this DAC is a large departure from other delta sigma DAC's designed by us and otherslike BB, ADI and Cirrus. The AK4396 is an entirely new modulator, pioneered and patened by AKM that does something unique. In the past many of the old phillips and BB parts were R-2R based products. These older products were looked upon as some of the best. One of the reasons was high freq noise. In older R-2R parts high freq noise was not present. In all delta sigma parts prior to the AK4396 everone fought high freq noise caused by the delta sigma modulator, putting large filters and other things to attempt to solve a problem created by the delta sigma design. The AK4396 today effectively does not have any high freq noise caused by the modulator, it is over 60dB better than the nearest Cirrus and BB devices. All this high freq noise can do many things down stream and end up as audible artifacts. That is the Miracle we belive is making the difference today. This part gives you the performance and linearity of a delta Sigma part while giving you the noise of an R-2R part. Something that was never previously available.

I recommend taking a listen to the products using the AK4396 such as APL's and the Slim Devices box. I think you will be plesently surprised. The AKM spends a lot of time and money working on sound quality it is something that makes working for AKM very enjoyable but it is also demanding. We listen to everything we produce and solicite outside very often for impressions on sound quality. However at the end of the day your own ears have to make the call.

Regards,
Richard Kulavik
AKM Semiconductor
rkulavik@akm.com

nonsub 2nd February 2010 04:27 AM

Spec wise though it seems almost identical to the previous version 4393 except what I posted.

data 2nd February 2010 04:44 AM

Read the cut & past I put up, It's a different design to other DAC's

"AK4396 this DAC is a large departure from other delta sigma DAC's designed by us and others like BB, ADI and Cirrus. The AK4396 is an entirely new modulator"

Those other specs tell very little about how the DAC chip works.

nonsub 2nd February 2010 05:20 AM

Sorry I have a marketing hype filter enabled :P OK I will be doing them anyway as I got 3 and am anxious to try my smt techniques on the DCX :)

Can you/anyone explain how the digital attenuation works on these, I don't understand from the specs. Thx!

data 2nd February 2010 05:22 AM

At the end of the day, due to the design differences in how the chip works, the AK4396 produces less hi-frequency noise than the other chips, that is the makings of a better sounding chip...

Someone else will be able to answer that question, I'm sure I can't :P

4real 2nd February 2010 08:28 AM

Quote:

Originally Posted by data (Post 2070286)
The AK4396 today effectively does not have any high freq noise caused by the modulator

I don't buy it, neither does the datasheet, stating:

"The internal switched-capacitor filters attenuate the noise generated by the delta-sigma modulator beyond the audio passband"

Any why would the filter be exactly the same, as the presumably so much different AK4393? That doesn't make sense... And for having such a revolutionary new modulator, AKM is fairly quiet about it, not even mentioning it..

Why is AKM about the only one that is not specing out of band noise, not even an simple picture...?

data 2nd February 2010 10:48 AM

4real, well that's what is stated by the guy from AKM in that post I cut & pasted from the other site, not myself.

Though I did swap the AK4393 out of a SRC2496 I had for the AK4396 and the AK4396 had such a black background I was stunned by it, unfortunately I killed the chip (my own fault) before I could optimise the output section of the SRC2496.

As for those questions, you would need to ask AKM themselves ;)

Jaimo 3rd February 2010 01:19 AM

Why Bother with a AK4396
 
The 4396 data sheet suggests that it's differential SCF output eliminates the need for a coupling capacitor, Is this not a good enough reason for changing to the 4396?

Also, a major "Gotcha" with upgrading a DCX or DEQ to a AK4396 has to be the higher output voltage - this chip is not a drop in replacement - one will have to change the driver stage to compensate for the higher output.

nonsub 3rd February 2010 01:45 AM

Quote:

Originally Posted by Jaimo (Post 2071598)
The 4396 data sheet suggests that it's differential SCF output eliminates the need for a coupling capacitor, Is this not a good enough reason for changing to the 4396?

No as far as I can makeout the 4393 has same? Also those are indeed coupling caps on the DCX (6 X 10uf) right?

Also, a major "Gotcha" with upgrading a DCX or DEQ to a AK4396 has to be the higher output voltage - this chip is not a drop in replacement - one will have to change the driver stage to compensate for the higher output.

That's why I was thinking one possible reason why people think it is improved sound (although I respect the other claims numerous ppl have made and will still do this mod myself.) There is evidence that people in listening tests think that louder is better sometimes in an A/B test where B has a slightly higher output.


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