what exactly does the allo usbridge do?

[ash87]

I think devices like the DigiOne are no longer required. All it does is provide a S/PDIF out. All the current DACs have switched to Asynchronous USB. Some DACs will support S/PDIF and TOSLINK but the prime focus is USB.

All you need these days is a RPi and a DAC.

That's really interesting. If I understand you correctly, you're saying that USB tech has advanced far enough to make the S/PDIF and TOSLINK inferior to (or as good as) USB? What about somethign like the USBridge with it's "electrically quiet USB output", is that significantly better than streaming straight from an RPi?

 

[kchap]

That's really interesting. If I understand you correctly, you're saying that USB tech has advanced far enough to make the S/PDIF and TOSLINK inferior to (or as good as) USB? What about somethign like the USBridge with it's "electrically quiet USB output", is that significantly better than streaming straight from an RPi?

In practice asynchronous USB is definitely superior. On well designed units the jitter performance on S/PDIF and USB will identical but for a lot of DACs jitter is often worse on the S/PDIF input; USB v S/PDIF. USB has more options such as high bit rates, DSD > 64 and controlling the volume from the streamer. Some DACs might just give one or two to extra options but, that is one or two more than S/PDIF.

Thing's like like low noise and/or galvanically isolated USB are often discussed but most users do not have problems with noise or earth loops. I could not find the link but I sure @Amirm has tested various low noise USB PSUs and isolators and found they make no difference.

Buy a DAC and a RPi, and load your software of choice. If you do have problems with noise or earth loops - and most users do not - try a different "off the shelf" PSU or a different outlet on the mains before you spend money on linear PSUs and galvanically isolated USB interfaces.

 

[EdTice]

In practice asynchronous USB is definitely superior. On well designed units the jitter performance on S/PDIF and USB will identical but for a lot of DACs jitter is often worse on the S/PDIF input; USB v S/PDIF. USB has more options such as high bit rates, DSD > 64 and controlling the volume from the streamer. Some DACs might just give one or two to extra options but, that is one or two more than S/PDIF.

Thing's like like low noise and/or galvanically isolated USB are often discussed but most users do not have problems with noise or earth loops. I could not find the link but I sure @Amirm has tested various low noise USB PSUs and isolators and found they make no difference.

Buy a DAC and a RPi, and load your software of choice. If you do have problems with noise or earth loops - and most users do not - try a different "off the shelf" PSU or a different outlet on the mains before you spend money on linear PSUs and galvanically isolated USB interfaces.

USB has been at least equivalent since around the time the iPod mini came out. That was in like 2004. Remember the USB interface was designed to carry data with complete accuracy. (Imagine how unpleasant it would be if every time you opened an Excel spreadsheet a few of the values had changed!) The issue with USB audio has never been about the USB interface itself. If I want to get audio say from a disk drive (PCIe to make it simple) to a USB DAC, the data has to be first read from disk and then sent over the USB interface.

Early USB implementations were interrupt-driven. This meant that if the host computer was performing an operation (such as saving a file, writing packets to ethernet, paging memory to disk, et cetera), the interrupt may not be handled quickly enough for smooth audio performance. This has been alleviated through three mechanisms. Computers are generally faster and operating systems better designed, USB host controllers now use "direct memory access" to avoid having to raise nearly as many interrupts, read-ahead buffers are used for disk IO. Even a Raspberry Pi has more horsepower than a high-end computer back when Windows XP was released.

I'm sure there are some really lousy USB audio implementations out there (and some really lousy SPDIF implementations). But the "electrical" problem we see with USB/SPDIF are about the same. SPDIF used to be better because SPDIF outputs were on PCIe interfaces that could use direct memory access... and USB didn't. That ship sailed a long time ago.

 

[tw99]

That's really interesting. If I understand you correctly, you're saying that USB tech has advanced far enough to make the S/PDIF and TOSLINK inferior to (or as good as) USB? What about somethign like the USBridge with it's "electrically quiet USB output", is that significantly better than streaming straight from an RPi?

No, it isn’t. A Pi4 using USB with any of the “Amir approved” DACs will be as good as anything. The audiophile industry will always find pointless stuff for people to worry about…

 

[EdTice]

No, it isn’t. A Pi4 using USB with any of the “Amir approved” DACs will be as good as anything. The audiophile industry will always find pointless stuff for people to worry about…

@ash87 See this thread. https://www.audiosciencereview.com/...ere-any-dac-with-checksum-capabilities.19081/ All USB packets include CRC so that the receiving end can tell if a packet is corrupted. Some devices (including some DACs) log this. If it's really important to you, get one of the DACs with this functionality and you can measure your 'error rate.' Probably close to zero. Then, if you want, ask to audition an 'electrically quiet' USB interface and see if there are any more or less errors recorded. My guess is that there will be no delta

 

[ash87]

This is all really helpful info. Thank you.

Next challenge is finding an RPi that's in stock somewhere, although I did see Adafruit is selling an RPi built into a keyboard for about $70.

 

[Apesbrain]

Next challenge is finding an RPi that's in stock somewhere

I sometimes see them available as part of a kit:

Raspberry Pi 4B Budget Kit

American Raspberry Pi Shop. One stop shop for all your Pi needs. Raspberry Pi add-ons, HATs, accessories, Starter Kit, Media Center kit, RetroPi Arcade kit, Ultimate Kit, and many other project kits. PiShop.us is approved Raspberry Pi re-seller and carries all official Raspberry Pi boards and...

www.pishop.us

 

[ash87]

I sometimes see them available as part of a kit:

Raspberry Pi 4B Budget Kit

American Raspberry Pi Shop. One stop shop for all your Pi needs. Raspberry Pi add-ons, HATs, accessories, Starter Kit, Media Center kit, RetroPi Arcade kit, Ultimate Kit, and many other project kits. PiShop.us is approved Raspberry Pi re-seller and carries all official Raspberry Pi boards and...

www.pishop.us

Nice, thanks for the tip.

 

[EdTice]

Nice, thanks for the tip.

How much of a hurry are you in? The shortage isn't as bad right now as it was even a few weeks ago. CanaKit is taking pre-orders to ship at the end of the month. You are probably going to have to do some sort of preorder as, otherwise, shipments might sell out as soon as they come in. But you won't be waiting months.

Raspberry Pi 4 2GB Model B

www.canakit.com

 

[sharagan]

Hi Guys,
I have a USBridge from Allo, which I bought back in the days, when I believed in snake oil (before discovering ASR ).
It is my understanding that many times addons for improvement result in a degradation of the result. Therefore my question:

Would it make sense to remove the USBridge board and only use the sparky board for streaming music?

Thanks in advance for any suggestions.

 

[Novak]

Hello everyone,I'm curious to know if the USBridge can offer an improvement in terms of responsiveness when streaming. For instance, when I press the play button, will the music start faster compared to using a Raspberry Pi 4? Can we expect an increase in the device's responsiveness? Any insights or experiences regarding this would be greatly appreciated. Thank you!

 

[voodooless]

Nope, it has zero impact on that.