Raspberry Pi I2S to SPDIF Hat

Sorry I was not clear. The Sabre DAC's can not be used since they always require SW control. Besides the AK4490 (and 4497) we can use the TI PCM179x family and the Analog Devices AD1955. Are there others I've missed?

Cheers,
Michael

 

Hi All, I made another case without LCD. It has openings for all outputs including analog RCAs. The microSD card can be swapped easily (via the opening on the bottom). The Pi3 onboard wifi has been hacked to be external with antenna.

Sounding wise, I haven't heard any significant difference. The last picture is the old unit on the left (with LCD using Michael's prototype board) and the new unit on the right.

Cheers.

 

@hifiandrun - Please send me the part number of the box you used. I will go ahead and pay to get a few of them custom cut for the board. If it works out, I will offer this as a standard in our store. Depending upon cost I will try to get them to the SBAF folks at a discount.

Cheers,
Michael

 

Hi Michael, Unfortunately, the box was purchased from a local store "You-do-it Electronics Center". I don't know the part number. I will check with them to see if I can get more info.
I don't have pro tools. Drilling these openings and filing them to the right size was not a fun job , but I am happy with the final result .

 

Most small box suppliers offer custom cutting, so if we can get the part number, or if you other folks find another option (prefer metal), then we can work with that.

Cheers,
Michael

 

This is an aluminum box. I will go to the store tonight and get back to you. Cheers.

 

That's nice @hifiandrun! -- Is that a multi color LED for the clock multiple? And the thin coax for the wifi probably moves that noise outside the box, did you remove the pi3's internal antenna?

 

Yes, that is a dual color LED

Regarding to the external wifi, I followed instruction on this webpage: https://www.dorkbotpdx.org/blog/wramsdell/external_antenna_modifications_for_the_raspberry_pi_3
I think that removing the onboard antenna should be easier. It is hard to move the zero-ohm resistor 45 degrees and solder a u.FL socket. The resistor is very small and easy to get lost without the right tools - I learned this the hard way. After move the zero-ohm resistor, the onboard antenna is disconnected.

There is one benefit hacking the Pi3 wifi - the wifi doesn't use the usb bridge, thus it will free up USB bandwidth when using a external USB hard-drive for music files.

 

Good idea. If you go ahead you may want to offer an option for plastic (or whatever) front/back panel(s) that'd let wireless signals in/out for those that don't want to do the external antenna mod, but like Scott I'd be interested in hearing more info on that hack from @hifiandrun.

Edit: already answered lol

 

Here's another option: a ModMyPi plastic case.





It's much less impressive, than hifiandrun's metal case , but it's an easily sourced one.

I used a ModMyPi case from Amazon and it was my first shot at customizing a case...if I can hack something together, anyone can!

 

Hi Michael, the box is a LMB Heeger model # EAS-200. I sent you a picture of the package via PM. Cheers.

 

For the new dac chips. This would be to provide better analog out? It wouldn't matter to the spdif output I currently use it or would it enhance it?

 

The change would only be to improve the analog out. Although most of you guys have been interested in the digital, some of you have tested the analog.And compared to a middle or high grade external DAC, it is not all that good.

The AKM [edit] DAC is what is used in a lot of external [edit] DAC's. The AKM AK4490 is what is used in the Schiit Audio products. Putting it on the shield, would in many ways make this combination as good as a discrete set up. And I know a number of you own those products so would be able to test and compare!

Cheers,
Michael

 

I could try and make a comparison between the analog out of the 502DAC (using the PCM5122) and the digital AES output to Aune S16 DAC that uses AK4495S. I guess AK4495S is similar to AK4490 you intend to use in the upgraded version of the 502DAC so this comparison would be welcome.
I don't know if the analog output of the 502DAC can be used simultaneously with the digital out so I can listen both on different inputs in my amplifier (Rega Elex-R) and switch between them and see the differences.

What methodology do you propose for making this test ...? Any suggestions of relevant songs used in this kind of test?

Thank you!

 

The 4490 and the 4495 are similar, but he 4490 has much lower THD (-109db vs -101db). As for test methodology, whatever works for you! Play music you are familiar with and give us your impressions. We know the specs will be better, but specs do not automatically translate into better or more pleasing sound. After all, that is in your head, and only your head!

Cheers,
Michael

P.S. Yes, digital and analog out occur simultaneously. Same data, same frame rate and same master clock on both.

 

I just ordered a 502DAC last night, do I have a long wait in the queue? Also for the planned updated version, do you anticipate a price increase?

 

The upgraded board will not replace the current version. They will be two separate products. The original is primarily for those who only need digital, and a modest but serviceable analog DAC. The new board will have a significantly upgraded DAC (maybe the PCM179x as well as the AKM as options) as well as high quality headphone amplifier using the LME49720 op amp driving the LME49600 buffer at peak output of 6V RMS. And it will be much more money! Probably close to $150. Right now I am thinking we will bundle it with a very low noise power supply for $199 total.

While that is more than most raspberry pi audio shields, the combination gives you a network based streamer that has the same level of audio quality you would expect from a $500-$1000 device. At least that's the hope!

As for lead time on the current board, we are building a batch this week and plan to ship early next week all of the current backorders.

Cheers,
Michael

[edit] P.S. open to suggestions on the 5V@4A (or better) supply.

 

Hi all,

I record the sound with Zoom H1.
There is analog output pcm5122. No bad, no bad.


Budget PCM1794 DAC ($200)


So far I have not made an opinion about the class of this product, I have to listen to the expensive DAC.
Thanks Michael!

 

Any updates?

Cheers,
Michael

 

Would there be any chance of a device that does ethernet in and I2S out (HDMI style)? Sonore used to have a big expensive unit that seemed grossly overpriced and the Pi platform seems suitable (to this uneducated reader anyways).