This is a review and detailed measurements of the HTC USB-C DAC and Headphone "dongle" aimed at mobile phone industry. It is on kind loan from an overseas member. I can only find overseas pricing for it but I think I found one site that listed it at USD $12. In that regard, it falls in the same price category of Google and Apple dongles.
As you can imagine, there is not much to this little adapter:
Hard to predict if the cable will fail sooner or later than its competitor.
Ghost in the Machine
When I received the HTC dongle, I had a heck of a time getting it to be recognized by Windows. I plugged it into the same USB-3 capable ports I use for testing every DAC. Here though, nothing would happen when I plugged it in. Reboot did not help either, nor would it show up in device manager in any way. I then tried it on my USB 2 front-panel and it worked! This is surprising as with other USB-C adapters, it is the other way around: the USB 3 port works and 2.0 doesn't. That was not all however.
I went to look at my past measurements for Google dongles as a comparison and I remembered that I had gotten inconsistent results there with respect to available power. After some investigation, it seemed that both Google dongles act differently depending on what load you have on them when you plug them in. In other words, if you hook up a 300 ohm headphone/load on it when you plug it in, the output power will be different than if you plugged it in using 33 ohm headphone/load. Highest performance was available when plugging in using high-impedance load and then switching to low impedance.
From what I recall, the HTC was backward yet again. To get the most power out of it, you had to first plug it in with a low load, and then switch to high impedance load.
This is quite troubling as without instrumentation and knowing the above, you have no idea what mode the adapter is in. So your experience may be different/worse than what the measurements show. This also explains why someone had trouble getting as much output out of the Apple dongle as I did in my testing.
Bottom line, like the LG phone I tested, all of these adapters have load sensing and decide how to operate to keep power consumption low as there is no space for them to dissipate any heat. Wish there was an LED or something to indicate operational mode. For now, this is a trade off you have when using such a cheap and light DAC+AMP.
Measurements
As usual we start with our dashboard:
This is not bad in grand scheme of things with respect to distortion/SINAD. It lands the HTC in our third tier performance bucket:
What is bad though is the anemic output voltage of just 0.8 volts. This will naturally hurt the power rating. Here is how much the HTC produces using 300 ohm load:
It does better than some of the other dongles like Google version 2 thankfully. At 2 milliwatts though, you can expect anemic response with such headphones.
Here is the performance using 33 ohm load:
Note that this has an update graph for Google V2 (in blue) where it now produces more power than earlier measurements showed. As such, the HTC loses to it by a bit, albeit with lower distortion.
Putting this data in context we get this:
Output impedance is a bit high and the reason it did not do better in 33 ohm test:
So be careful in using headphones with variable impedance that is below 50 ohm.
Listening Tests
As expected, the experience with high impedance headphone like my Sennheiser HD-650 was not that great. Bass was subdued and overall, there was not enough volume for more than background listening. Switching to lower impedance Hifiman HE-400i made the situation better. Here, at max volume, we had pretty decent sound. Mind you, it won't even come close to competing with desktop products or more powerful dongles but it did OK.
For someone like me who craves power, there is nothing that compels me to recommend the HTC headphone dongle.
------------
As always, questions, comments, recommendations, etc. are welcome.
We have beautiful sunny weather. So I am thinking about getting some fish chips in a town 35 miles away and need gas money. Please consider donating funds using:
Patreon: https://www.patreon.com/audiosciencereview), or
upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).
As you can imagine, there is not much to this little adapter:
Hard to predict if the cable will fail sooner or later than its competitor.
Ghost in the Machine
When I received the HTC dongle, I had a heck of a time getting it to be recognized by Windows. I plugged it into the same USB-3 capable ports I use for testing every DAC. Here though, nothing would happen when I plugged it in. Reboot did not help either, nor would it show up in device manager in any way. I then tried it on my USB 2 front-panel and it worked! This is surprising as with other USB-C adapters, it is the other way around: the USB 3 port works and 2.0 doesn't. That was not all however.
I went to look at my past measurements for Google dongles as a comparison and I remembered that I had gotten inconsistent results there with respect to available power. After some investigation, it seemed that both Google dongles act differently depending on what load you have on them when you plug them in. In other words, if you hook up a 300 ohm headphone/load on it when you plug it in, the output power will be different than if you plugged it in using 33 ohm headphone/load. Highest performance was available when plugging in using high-impedance load and then switching to low impedance.
From what I recall, the HTC was backward yet again. To get the most power out of it, you had to first plug it in with a low load, and then switch to high impedance load.
This is quite troubling as without instrumentation and knowing the above, you have no idea what mode the adapter is in. So your experience may be different/worse than what the measurements show. This also explains why someone had trouble getting as much output out of the Apple dongle as I did in my testing.
Bottom line, like the LG phone I tested, all of these adapters have load sensing and decide how to operate to keep power consumption low as there is no space for them to dissipate any heat. Wish there was an LED or something to indicate operational mode. For now, this is a trade off you have when using such a cheap and light DAC+AMP.
Measurements
As usual we start with our dashboard:
This is not bad in grand scheme of things with respect to distortion/SINAD. It lands the HTC in our third tier performance bucket:
What is bad though is the anemic output voltage of just 0.8 volts. This will naturally hurt the power rating. Here is how much the HTC produces using 300 ohm load:
It does better than some of the other dongles like Google version 2 thankfully. At 2 milliwatts though, you can expect anemic response with such headphones.
Here is the performance using 33 ohm load:
Note that this has an update graph for Google V2 (in blue) where it now produces more power than earlier measurements showed. As such, the HTC loses to it by a bit, albeit with lower distortion.
Putting this data in context we get this:
Output impedance is a bit high and the reason it did not do better in 33 ohm test:
So be careful in using headphones with variable impedance that is below 50 ohm.
Listening Tests
As expected, the experience with high impedance headphone like my Sennheiser HD-650 was not that great. Bass was subdued and overall, there was not enough volume for more than background listening. Switching to lower impedance Hifiman HE-400i made the situation better. Here, at max volume, we had pretty decent sound. Mind you, it won't even come close to competing with desktop products or more powerful dongles but it did OK.
For someone like me who craves power, there is nothing that compels me to recommend the HTC headphone dongle.
------------
As always, questions, comments, recommendations, etc. are welcome.
We have beautiful sunny weather. So I am thinking about getting some fish chips in a town 35 miles away and need gas money. Please consider donating funds using:
Patreon: https://www.patreon.com/audiosciencereview), or
upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).