Pi 2 Design Mercury Streamer

[chipvn]

On 11/17/2022 at 6:15 PM, Navin said:

As per what I remember, Allo had stated that there should be no advantage in using CM4 over the CM3+ version used in the USBridge Signature. 

 

At least when used with the RPi4, the CM4 equipped RPi4 has higher power consumption and slightly noisier than a CM3+ equipped RPi3B+ (via USB output).  The stock USBridge Signature works at 384Khz on i2s and DSD 512 via USB. 

I'm afraid that I could not agree on this assumption.

The CM4 running on USBridge Sig is obviously much more powerful than the original CM3+. With the CM3+, there is no way for me to output DSD256 with any real time kernel without static pop/click on my unit regardless of OS used. With CM4 module, I can output DSD512 with real time kernel on GentooPlayer with easy!

For the noise, I don't understand the basis to comment that the CM4 is noisier. Without any modification, the CM3 to Cm4 adaptor board use switching power IC to step up the 3.3V that feed the CM3+ to 5V that the CM4 required and thus, it might be noisier. Howerver, it is not too dificult to remove this switching stepup power IC and take directly 5V clean power from the GPIO to provide the CM4.

We can always order the CM4 without WIFI/Bluetooth/eMMC so basically there is no addtional noise generate.

There is no available option at this moment to use the built in Ethernet interface of the CM4 on the USBridge Sig. Therefore, it is still using the ASIX Ethernet to USB  chip then sharing the same USB hub using the TI chip of the USBridge Sig which is also use for USB output.

The whole CM4 modified solution still has all the advantages of the USBridge Sig but with a more powerful chip of the newer generation.

I can use either Roon Bridge or HQPlayer NAA to stream DSD512 with real time kernel on GentooPlayer64 with the CM4 running max at only 800MHz on the Allo USBridge Sig and the unit is still much cooler than the stock CM3+ that can only do DSD256 with normal kernel!

 

Back to the Pi2Design Mecury V2, it seems to be a really nice unit for those who need i2S/SPDIF interface. However, for those who just need USB output, it could be a bit overkill. A Mecury V2 light (or something similar) with just a USB interface might be a better solution for this user group.

[chipvn]

4 hours ago, RichardSF said:

If you only need USB output, you only need a Raspberry Pi 3 or Pi 4, and you have many choices for kits. The Mercury was created to provide high quality i2S/SPDIF outputs. It is the only reason for the Mercury to exist.

The main reason why Pi3B+ or Pi4 might not be an ideal solution for a number of user is there are DC to DC switch power conversion components on board that could create sufficient noise (either audible or electronical). My standard Pi3B+ create significant audible noise in rather quiet room.

That's why there is product like the USBridge Sig (with just USB output) which has zero DC to DC switching power conversion on board.

There are still some limitation on the USBridge Sig there for I'm still looking for something like a simplified version of the Mecury or Holo Red. Might be the StackAudio Link II is one of them but the price is a bit steep.

[chipvn]

5 hours ago, Navin said:

I didn't know the CM4 board could replace the CM3+ in the USBridge. To me they look so different with different connectors. I don't know much, I just relayed what Allo said when asked about when they are upgrading the USBridge from CM3+ to CM4. I didn't know there was a "CM4 modified solution". How complicated is this? Can a newbie like me do it (I have the USBridge). 

I shared mine here, you need to have an adaptor and a bit of customization.

 

 

 

 

There is dedicated topic for it so you can have more reference information there as well.

 

Sorry to all for the off-topic discussion.