Question about Topping DX1 II

[lovetl2002]

I’m currently considering buying a DAC + AMP combo for my HD 600. The newly released Topping DX1 II fits my needs quite well in terms of features, but I’m a bit worried whether its driving power is sufficient. I need 10 dB room for EQ. Since this unit is powered solely via USB, if I connect it to my iPhone 15, the maximum power it can draw would be 4.5W, instead of 15W from a PC USB-C port. I’m also wondering whether, if I use an adapter to convert the 4.4mm jack to a 3.5mm jack, the output power would remain the same, or reduced to just one quarter of the the 4.4mm output power.

 

[staticV3]

Hi @lovetl2002! Welcome to ASR.

I rarely need more than 1.0Vrms for my HD600 (with full correction to Harman OE2018), so the 4.2Vrms (3.5mm) / 8.3Vrms (4.4mm) that the DX1 II can provide should be complete overkill (at least they would be for me).

4.5W input should be fine, after all the headphone Amp will almost certainly be fed from an internal capacitance and thanks to the crest factor of music, that enables much greater instantaneous output power compared to the constant input power.

And that's ignoring the fact that the 300Ω HD600 will barely permit any current, and therefore power, to flow anyway. It's effectively purely voltage driven.

Lastly, Never Ever convert a differential headphone output like 4pin XLR or 4.4mm Pentaconn into a single-ended output for connecting your 3.5/6.35mm headphones.

It's very likely that this will short the Amp's outputs, which if you're unlucky can fry the output.

The basic rule of thumb is that if your headphones have a differential connector (4pin XLR, 4.4MM Pentaconn, 2.5mm TRRS), then you can adapt and plug them into any headphone jack you want.

But if your headphones have a 3.5mm or 1/4" connector, then you'll have to stick to 3.5mm and 1/4" jacks.

 

[spigot]

At 300 Ohms with 3.5mm it's half as powerful as the DX1 (22mW vs 45mW). Might be related to the digital volume control of the DX1 II (and other features).

 

[staticV3]

At 300 Ohms with 3.5mm it's half as powerful as the DX1 (22mW vs 45mW). Might be related to the digital volume control of the DX1 II (and other features).

Look again.

At 300Ω:
DX1 3.5mm -> 51mW
DX1 II 3.5mm -> 58mW.
DX1 II 4.4mm -> 230mW.

 

[Roland68]

I’m currently considering buying a DAC + AMP combo for my HD 600. The newly released Topping DX1 II fits my needs quite well in terms of features, but I’m a bit worried whether its driving power is sufficient. I need 10 dB room for EQ. Since this unit is powered solely via USB, if I connect it to my iPhone 15, the maximum power it can draw would be 4.5W, instead of 15W from a PC USB-C port. I’m also wondering whether, if I use an adapter to convert the 4.4mm jack to a 3.5mm jack, the output power would remain the same, or reduced to just one quarter of the the 4.4mm output power.

Your information regarding the power requirements of the DX1 II is not entirely accurate.
The DX1 II draws a maximum of 2.5 watts via USB—specifically, 5.0 volts at 1.0 A.
Therefore, you should not encounter any issues.

At 300 Ohms with 3.5mm it's half as powerful as the DX1 (22mW vs 45mW). Might be related to the digital volume control of the DX1 II (and other features).

That has absolutely nothing to do with it.
The DX1 II is a balanced headphone amplifier featuring four amplifier branches; consequently, it possesses a completely different amplifier architecture than the older DX1 II, which had only two branches.
Typically, power output quadruples when switching from single-ended (SE) to balanced mode—something the DX1 II demonstrates very effectively.

 

[solderdude]

I’m currently considering buying a DAC + AMP combo for my HD 600. The newly released Topping DX1 II fits my needs quite well in terms of features, but I’m a bit worried whether its driving power is sufficient.

It is, certainly from 4.4mm you can even play very loud (120dB SPL peaks, average will be 105-115dB with dynamic music).
On TRS out you get 6dB less maximum SPL but still a loud 114dB peaks.
Peak power in music will not be drawn directly from the USB power so while there may well be peaks drawing 0.5W (balanced) the average power draw at these high listening levels will be around 0.05W. Then there is some loss in the amplifier itself amounting to around 0.03W.
Also there will be some base current being drawn (USB receiver, DSP, processor, display etc. which will be the biggest contributor.

This means when playing HD600 VERY loud it will only draw about 0.1W more than its standard power draw.
Nothing to worry about...
It becomes another thing when it will be powering insensitive low impedance planar headphones but that's not the case.

I’m also wondering whether, if I use an adapter to convert the 4.4mm jack to a 3.5mm jack, the output power would remain the same, or reduced to just one quarter of the the 4.4mm output power.

You can always safely use an adapter that converts from a TRS output to a 4.4mm plug from a headphone.

The other direction can be a bit tricky ... so 4.4mm output of an amplifier being connected to a TRS plug of a headphone.
When such an adapter is wired correctly AND the 4.4mm output from the source is FULLY connected (meaning the sleeve is connected to the audio ground) then such an adapter can be used BUT you will only get 1/4 of the power output of the 4.4mm balanced spec.

You are simply just using 2 amplifiers of the available 4 in the source.

Be careful though as not all of those adapter(cable)s are always correctly wired and those could potentially damage the source as L- and R- might simply be tied together (shorted) in those adapters.

The DX1 II draws a maximum of 2.5 watts via USB—specifically, 5.0 volts at 1.0 A.

2.5W at 5V = 0.5A.

The big question would be what the 'idle' current draw is from the DX1-II.
This is not in the specs and have never seen such numbers mentioned in any review.

For instance the power-input of my E30 (which is a desktop DAC only, no amp, no DSP) is 0.23A (4.94V) = 1.1W when doing nothing but being 'on'.
An UMC202HD draws 0.17A in idle.

All way below the spec for USB-C outputs (max 0.9A) iphone 15 and newer.

Lightning outputs, however, are limited to 0.1A (0.3A short peaks).

 

[Roland68]

2.5W at 5V = 0.5A.

The big question would be what the 'idle' current draw is from the DX1-II.
This is not in the specs and have never seen such numbers mentioned in any review.

For instance the power-input of my E30 (which is a desktop DAC only, no amp, no DSP) is 0.23A (4.94V) = 1.1W when doing nothing but being 'on'.
An UMC202HD draws 0.17A in idle.

All way below the spec for USB-C outputs (max 0.9A) iphone 15 and newer.

Lightning outputs, however, are limited to 0.1A (0.3A short peaks).

Sorry, I must have been asleep.

Standby power consumption for the DX1 II is 0.8 watts.
Typical power consumption is approx. 2.5 watts (5V/0.5A).
The recommended power supply is 5V/1A.

According to Topping's specifications, the DX1 II should be fully powered via standard USB 2.0 ports.

If I get my hands on a DX1 II in the coming weeks, I'll take some measurements to verify this.
However, @amirm might test it sooner, as it is an extremely interesting device for the mass market.

 

[solderdude]

Standby power consumption for the DX1 II is 0.8 watts.

0.16A is not that much.
With the HD600 playing at full volume it will be consuming less than 1W (0.2A)

I can certainly see driving low impedance planars at high level will certainly requiring 1A or so.

 

[mdmower]

According to Topping's specifications, the DX1 II should be fully powered via standard USB 2.0 ports.

As a heads up, this device appears to require every bit of power a USB 2.0 port can provide during startup. My 4-port USB 3.0 hub is externally powered; when it only had a 2.4W charger providing power, the DAC took down the whole hub (none of the devices worked). I switched to a 30W USB-C charger and now the hub works fine. During startup, the max power draw I saw was 2.61W (picture below), which technically exceeds the 2.5W max of USB 2.0, but if this were the sole device on a USB 2.0 port, then yes, I think it would manage.

Sorry, I don't have low impedance headphones on hand to test power draw when properly loaded. My HD598 HD 599 SE headphones only resulted in 2.31W at 0db.

 

[Roland68]

As a heads up, this device appears to require every bit of power a USB 2.0 port can provide during startup. My 4-port USB 3.0 hub is externally powered; when it only had a 2.4W charger providing power, the DAC took down the whole hub (none of the devices worked). I switched to a 30W USB-C charger and now the hub works fine. During startup, the max power draw I saw was 2.61W (picture below), which technically exceeds the 2.5W max of USB 2.0, but if this were the sole device on a USB 2.0 port, then yes, I think it would manage.

Sorry, I don't have low impedance headphones on hand to test power draw when properly loaded. My HD598 headphones only resulted in 2.31W at 0db.

View attachment 535926View attachment 535923

This is understandable, since—with a 2.4-watt power supply/charger—an active USB 3.0 hub consumes power itself. If an additional 0.1-0.2 watts are missing, that's a problem, especially with other devices connected to the hub...

Is that the power consumption of just the D1X II without the hub?
Could you please measure the power consumption of the D1X II using a USB 2.0 cable, or the original cable included in the box?

 

[mdmower]

Is that the power consumption of just the D1X II without the hub?
Could you please measure the power consumption of the D1X II using a USB 2.0 cable, or the original cable included in the box?

Oh, right, I should have mentioned that. The power meter was only measuring the DX1 II and that was with the USB-C to USB-C cable that came in the box. The highest power reading I've seen is 2.84W.

I got an old computer out of storage that has a USB 2.0 port. The DX1 II powered up just fine off of only that port. It did read 2.60W during startup, so it took everything it could get from the port, but it eventually settled down to 2.25W while idle and 0.78W in standby mode.

[  582.523899] usb 1-2: new high-speed USB device number 6 using xhci_hcd
[  582.661586] usb 1-2: New USB device found, idVendor=152a, idProduct=8750, bcdDevice= 2.46
[  582.661608] usb 1-2: New USB device strings: Mfr=1, Product=3, SerialNumber=0
[  582.661614] usb 1-2: Product: DX1 II
[  582.661619] usb 1-2: Manufacturer: TOPPING
[  582.699068] input: TOPPING DX1 II as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.4/0003:152A:8750.0006/input/input19
[  582.699302] hid-generic 0003:152A:8750.0006: input,hidraw0: USB HID v1.10 Device [TOPPING DX1 II] on usb-0000:00:14.0-2/input4

 

[solderdude]

Should not be a problem for phones with USB-C out (0.9A) but it will drain its battery quite a bit more.
For USB 1-2 it will require an additional power supply.

At max output power (2x 1W) it will likely draw an additional 1.5W and will be close to the max, 0.9A of USB3-C spec.

 

[Gradius]

Still no review of this puppy?

 

[Demmers]

Still no review of this puppy?

Not from the likes of Amir, but there's plenty more chat about it here https://www.audiosciencereview.com/...me-info-about-toppings-incoming-dx1-ii.69841/
As an owner myself, the only gripe that others also have is a sound bug, where crackling may appear after a period of time. Changing the input/re-connecting the USB cable stops this. The latest firmware update 2.54 says it was meant to resolve a sound bug, but either that hasn't worked, or they were looking at something else.
Apart from this, it works as advertised. Still glad I have it, a nice "upgrade" to my Topping D10s and JDS Labs Atom mk1.

 

[Bleib]

Still no review of this puppy?

If Amir doesn't review it then at least NTTY will. So at least we know it's coming.