There should be USB-C audio amplifiers.

[amano]

There are already USB-C headphone amplifiers for low impedance headphones, but I want USB-C PD(power delivery) power amplifiers as well.

USB-C PD 3.1 cable can carry both power and data. For computers that lack USB-PD ports, the amp can be powered by a USB-PD charger.

USB-PD 3.1 can supply up to 5A at 20V, 28V, 36V, and 48V. That's enough power for a room audio system.

Specification	Current (max.)	Voltage	Power (max.)
Low-power device	100 mA	5 V	0.50 W
Low-power SuperSpeed (USB 3.0) device	150 mA	5 V	0.75 W
High-power device	500 mA	5 V	2.5 W
High-power SuperSpeed (USB 3.0) device	900 mA	5 V	4.5 W
Battery Charging (BC) 1.2	1.5 A	5 V	7.5 W
Single-lane SuperSpeed+ (USB 3.2 Gen 2×1) device	1.5 A	5 V	7.5 W
Power Delivery 3.0 SPR	3 A	5 V	15 W
Power Delivery 3.0 SPR	3 A	9 V	27 W
Power Delivery 3.0 SPR	3 A	15 V	45 W
Power Delivery 3.0 SPR	3 A	20 V	60 W
Power Delivery 3.0 SPR Type-C	5 A	20 V	100 W
Power Delivery 3.1 EPR Type-C	5 A	28 V	140 W
Power Delivery 3.1 EPR Type-C	5 A	36 V	180 W
Power Delivery 3.1 EPR Type-C	5 A	48 V	240 W

USB-PD chargers are increasingly being used to power everything.

 

[voodooless]

It's not super convenient to have both data and power go through the same cable, because most data sources are not equipped to also supply high power and voltage to a target device.

But yeah, one could make an amp running on a USB-PD power supply.

 

[kemmler3D]

Would only really make sense for PCs that have the highest spec PD ports, not sure how common that is. Otherwise you still need to plug into the wall so it's whatever, just a more expensive power supply.

I'm sure there are more situations where it could make sense but my brain fails me at the moment.

 

[respice finem]

I think such amps will emerge quite soon, allowing manufacturers to at least get rid of potential RMA because of "power brick" problems.
On the other hand, the overall power delivery of a given PC is finite, so the shared power draw might reach its limit sooner than expected, if other devices are running.
Therefore, I would still prefer at least more potent amps to be self-powered rather than bus-powered. But the idea is nice in itself, giving the user more choice of power sources without a myriad of proprietary plugs. Choice is a good thing.

 

[MCH]

For small desktop amps, i expect and hope that in a couple of years USB-PD will be the standard. One could have one single PSU for all the devices on the desk. I currently can charge even my laptops with a small 20W charger when i travel. Yesterday Allthingsoneplace reviewed a 380W charger....what i have no idea is how these chargers cope with variable loads.... For the moment, seeing allthings. reviews, it seems that the current chargers are a bit complex in the way the assign priorities and power to each port, so perhaps we are not there yet and someone will need to sell dedicated ones.

 

[kyuu]

Not really sure I see the advantage over just having an integrated power supply in the amp, like the Wiim lineup. Then you just connect it to AC power. Unless you want something very compact and low power, I guess? Few USB power supplies I've seen do much more than a few tens of watts unless it's a laptop power supply, but using one of those isn't really any different than what you're using now except for the connection on the end.

 

[RogersCompactMonitorFan]

It's not quite what you're saying, but almost is:

I've had success using a USB PD trigger cable to power my Aiyima A07 amplifier from a battery. - Search "USB PD trigger Barrel jack cable" or similar.

The TPA3255 amplifiers seem to be happy at 20v.

It's quite neat running a HiFi with a phone as an audio source and the amplifier powered from a power bank. Did this for a while and had a solar powered HiFi.

You can also get little trigger boards which have a USB-C connector on and I think might fit into an amplifier as a modification - removing the power socket and squeezing one of these in its place. Maybe in a similar vein there is a little USB-C DAC board somewhere which could fit and replace the input connectors.

 

[raif71]

After the usb-c , there could be the gpmi

 

[milus]

I would like to see this USB-C PD implemented in desktop monitors.

 

[amano]

If it is not desirable to deliver power over data cable, you can have a separate power cable.

180~240 watts are quite enough for a personal room.

If the power is delivered by USB-PD 3.1 and the data are delivered through a separate USB-C port, then all you need is USB-C ports and USB-C cables and USB-C PD 3.1 chargers.

You can also convert USB-PD 3.1 to a DC jack with a USB-PD trigger cable.

 

[EJ3]

If it is not desirable to deliver power over data cable, you can have a separate power cable.

180~240 watts are quite enough for a personal room.

If the power is delivered by USB-PD 3.1 and the data are delivered through a separate USB-C port, then all you need is USB-C ports and USB-C cables and USB-C PD 3.1 chargers.

You can also convert USB-PD 3.1 to a DC jack with a USB-PD trigger cable.

It may be a scale of production issue: the more they can sell, the lower the price, if less people want it, it may be pricier than more powerful items.

 

[NTK]

Why not just stick with the PoE (power over ethernet) solutions. For example, PowerSoft has the tiny Nota 142 that runs off AES67 and has built in DSP.

It doesn't have the 5 m cable length limitation of USB-2 (shorter for USB-3) and have the other problems such as latency, high channel count (multiple units/channels) solved.

Powersoft tiny PoE Power Over Ethernet AES67/USB Nota amplifier with DSP

Powersoft is more in the industrial and commercial world not the audiophile world. No doubt they would be using the same chips as everyone. One use case is the distributed PA system in a hospital with speakers down a passageway. All the wiring to do that is a lot of work. This is the type of...

www.audiosciencereview.com

 

[voodooless]

Why not just stick with the PoE (power over ethernet) solutions

That’s currently 100W max (PoE++), still okay for a lot of things. You’ll be fairly limited in switch choices, though.

You can expand the power budget with a battery buffer, since music has a fairly high crest factor, you could easily power a 200 or 300W amp with a much lower PoE power input. All of this does add significant cost, though.

 

[NTK]

PoE just for power delivery?

Both power and audio signal. One cat 5 cable does it all.

 

[amano]

AES67 seems more complex than USB-C PD.

 

[just1n]

After having to swap out a device and realizing the spaghetti I was dealing with the biggest frustration was power. Playing Tetris with plugging in devices is immensely frustrating. I’d take a USB-C surge protect to power more devices than this nightmare any day. Too many don’t require this adapters because of how low demand they are.

 

[NTK]

AES67 seems more complex than USB-C PD.

For good reasons. For example, how would USB deal with multiple devices if you need more than one?