Raspberry Pi I2S to SPDIF Hat

Sorry I dont mean the physical volume knob but how the Volumio volume control (on the gui) interact with the 502DAC pro board/ Spdif interface out to the external DAC.

I just wonder if the volume control is dealt with differently.
1. RPI3 USB -> USB DAC
2. RPI3 / 502DAC pro Spdif (toslink to be exact) -> DAC

ps. It is the same iFi iOne DAC just using different interfaces.

 

I am not sure if Volumio supports the limited hardware volume control inside the PCM5122 DAC. The software volume control simply modifies the signal before it leaves the pi, and is known to create small, but potentially audible errors. Your best bet is to select none for volume control in Volumio and rely on your downstream DAC or amplifier to control the final volume.

Cheers,
Michael

 

Hi Michael,

1 more question. Is the the DC Jack spec. confirmed? I plan to order a LPS for it. Thx.

8.2 J1 – DC JACK This jack is designed to accept a 5.5mm x 2.5mm center positive plug for external power in. Voltage must be 5V +/- 10%.

 

Correct.

Michael

 

I plan to buy this LPS to power the RPi3 and later may be use it for the 502DAC pro hat.

What do you guys think?

https://world.taobao.com/item/525221374183.htm?spm=a312a.7700825.1997196601.18.45c5a63fMZu2Eh

 

If you are in China and don`t have to pay import-tax and shipping...it might be a good deal. I am no electrical-engineer mind you so I can`t tell if the used parts are high quality or not. Add to that that the designer of the 502 denies there is an improvement in audio-quality with an LPS and you might want to spend the extra cash on a fancy cable. If you want to go full raspberry(long-term and with different HATs) having an LPS around is a good idea anyways. So it`s up to you I say!

 

Just to be clear, I don't deny there is a difference, I just can't measure it! As I said, human hearing is very complex and not all we can hear can be measured reliably.

Cheers,
Michael

 

I am not exactly in China but I am in HK.
Since I need to buy a power adapter so may as well buy a cheap LPS since I never own one and want to try it. Someone said this one is only good for 2A (although the seller said it goes upto 4A) which is not enough for my need.

Another option is just to get the 5V ipower which is a bit cheaper but I heard many die after a few months.

 

Sorry Micheal! It`s true. That is what you said.
I just hear someone speaking Engineer saying: I can`t meassure it!
So I just assumed that means it`s not there to you and the other engineers .

 

What he means is that the accepted, well implemented measurements may not be discriminating enough to capture all the subtleties of human hearing. If you are curious about the history of the science and engineering of human hearing, and what digital systems make of it, there are much worse investments than spending some quality time with https://www.cambridge.org/core/books/human-and-machine-hearing/3660166B40020EE587D94BB7A309FC12. Full disclosure: the author is a colleague, but he does not know of this endorsement.

 

Guys and Gals,

Just posted a new thread about our new 502HTA Tube DAC/Amp for the Raspberry Pi. Take a look and let me know what you think. Some of you may recall this thread started as an offshoot of our original 503HTA Tube DAC/Amp.

Cheers,
Michael

 

Hi Michael,
I am looking for an amp for my alarmclock/radio-pi.
This one looks like it may produce some heat. Would it need a fan in a closed housing you think?

 

If you don't mind, please ask this in the other thread so we can get the conversation rolling.

Cheers,
Michael

 

NVM

 

Just updated one of my volumio`s and saw the 502DAC appear in the dropdown for dacs. Shitty part is that my pi with the 502 has the OTA update bug.
So looks like a full reflash to make good use of it.

 

Hi Michael,

I already told you I had this issue with the connection dropping when I touched the BNC cable.
I was still hoping it would be the cable but I tried another cable just now and the signal still drops when you touch it or move the raspberry.
Before that I already made sure there is no way the soldering joints on the bottom of the board touch anything and short.
Anything else you think I should try? Please keep in mind I`m a fatfingered noob that is just about able to hold a soldering iron

 

Anyway you can test the other digital outputs? Right now my best guess is the BNC connector itself or the soldering of it. I can't replace your unit until about 2 weeks, so if you're brave enough, go ahead and try to see if the pins look correct. Or send it back and we'll fix or replace as soon as possible. I am sorry this is happening to you.

Cheers,
Michael

 

I already looked at the joints when I took of the board to make sure nothing was shorting under there.
Couldn`t detect one that was off or seemed different. I`ll try the optical port and see what happens.
Don`t be sorry yet!

Edit:
I can wiggle the optical all I want. No drops.
So it probably is a bad connector or joint.

 

Hi Michael, what is the currect expected delivery date of the Pro model? Thx.

 

We should start shipping about 3-4 weeks after the campaign dens. It takes Indiegogo up to 2 weeks to transfer the funds. We have per-purchased some of the components, but will need those funds to complete the build.

Cheers,
Michael