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ddHiFi TC44B Review (Headphone Adapter)

amirm

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This is a review and detailed measurements of the ddHiFi TC44B balanced portable DAC and headphone amplifier. It was kindly sent to me by a member and costs US $90 although I think Drop carried it for $80.

The TC44B brings a bit of departure in form factor in its triangular shape:

ddHifi TC44B review portable headphone adapter dongle.jpg


A permanent USB-C cable comes with it. As you can see, there are only provisions of "balanced" headphones in the form of 2.5 and 4.4 mm jack. Please do NOT attempt to convert this to 3.5 mm unbalanced as that can damage the unit. You have to have balanced wiring for your headphone to use this adapter.

ddHiFi TC44B Measurements
As usual we start with our dashboard of 1 kHz tone:

ddHifi TC44B measurements balanced.png


This is excellent performance, landing the TC44B near top of the class:

best headphone dongle review.png


There are countless DACs including some costing thousands of dollars which can't attain this level of performance!

Unfortunately the output level is only 2 volts. This will hurt the performance of TC44B on high impedance headphones as we will shortly see.

Dynamic range is excellent which should yield very low noise floor for sensitive IEMs:

ddHifi TC44B DNR measurements balanced.png


Jitter test is a weak point for many portable dongles but not this device:

ddHifi TC44B jitter measurements balanced.png


Multitone shows the same low distortion results:

ddHifi TC44B multitone measurements balanced.png


Like most dongles, the way the TC44B advertises itself to Windows causes my ASIO interface emulation to get confused and produce higher noise and distortion. In the above tests, I did not use that scheme and instead just played the test tones using my Roon player. For sweep tests however, I have to use the ASIO layer so don't go by the noise floor and just pay attention to the maximum power:

ddHifi TC44B Power into 300 ohm measurements balanced.png


best portable headphone amp 300 ohm review.png


With balanced dongles we are able to get 4 volts typically. But since the TC44B only outputs 2 volts, it suffers here relative to the top ranked devices. At the same time, it is miles ahead of those that only output 1 volt.

Current delivery is very good though so with 32 ohm load, we get top class performance:

ddHifi TC44B Power into 32 ohm measurements balanced.png

best portable headphone amp 32 ohm review.png


Company spec is 120 milliwatts which is what we measured.

TC44B Headphone Listening Tests
Performance with my Drop Ether CX headphone which is 25 ohm was excellent. I could get plenty of volume and satisfying experience. I swapped the cables on my Sennheiser HD-650 to balanced and there, with content that was mixed loud, there was plenty of volume and excellent performance. With content that was less so, it was still loud but borderline.

Conclusions
The TC44B nails objective performance, producing desktop class performance in a tiny package. Its output though is half as much as the other balanced dongles we have tested so can't drive high impedance headphones as loud. With low impedance, it is there with distortion and noise-free performance.

I am happy to put the ddHifi TC44B on my recommended list. It is very well executed DAC and headphone amplifier.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
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vkvedam

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Wow! If it can drive your Ether to satisfactory levels then I am impressed
 

GWolfman

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Looks like good for 150 ohm (e.g., HD 58X Jubilee) and borderline 300ohm. Worth a consideration on my part... Thanks!
 

martijn86

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If power is sufficient, this should even be a nice desktop upgrade. If you're on a budget then the TC44B can be one device that does it all. Plug it in your desktop PC or take it with you. $90,- and you can rest assured knowing that your DAC/amp is clean.
 

Tks

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Looks pretty good. Even though seeing as how it's not producing more power which usually means better things like SINAD and such - it still manages good results throughout except for the aforementioned power output it seems.

Also, this shape is pretty cool tbh.

One thing that's annoying is it uses those audiophile IEM style braided cables that I feel won't last much at all. No relief at the connection either. Really wish companies would stop doing that, but then again, it's a ~$90 DACAMP, so can you really complain too much from a relatively unknown company?
 

Palfim

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I think Amir mentioned the spreadsheet he uses didn‘t have that unit on it for some reason, and maybe he just forgot to add it back in.
At that time he only had a 50 ohm unit for balanced measurements, I think the 9038s did 220mw before clipping .

This may be the best dongle for sensitive IEMs. Out of the hidisz s9 , eida 9038d or s, it has the best dynamic range (123 dB) should be lowest noise yet ?
 
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dorirod

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Thank you for the review @amirm. Small typo here "Unfortunately the output level is only 4 volts."
 

TK750

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At that time he only had a 50 ohm unit for balanced measurements, I think the 9038s did 220mw before clipping .

This may be the best dongle for sensitive IEMs. Out of the hidisz s9 , eida 9038d or s, it has the best dynamic range (123 dB) should be lowest noise yet ?

I think there was a slight error in measuring the 9038D with the analyser, if you read this post here and the one after it, I think the 9038D has either the same or slightly better dynamic range.
 

Spocko

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So this sounds perfect for IEMs which are sensitive - I just bought it for my IEM plugged into my Macbook Air! Wait... it is compatible with the Mac OS right?
 
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Spocko

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Question regarding the 2.5mm vs 4.4mm connectors. The product literature says the 4.4mm balanced connectors are "grounded connected, so it’s more suitable to use with balanced active speakers." So does that mean I shouldn't use the 4.4mm balanced connectors on my IEM and should instead buy another 2.5mm balanced cable for IEM use? What exactly would be the problem if I plugged my IEM into the 4.4mm balanced input?
 

AdamG247

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I think there was a slight error in measuring the 9038D with the analyser, if you read this post here and the one after it, I think the 9038D has either the same or slightly better dynamic range.
Welcome Aboard @TK750.
 
OP
amirm

amirm

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Question regarding the 2.5mm vs 4.4mm connectors. The product literature says the 4.4mm balanced connectors are "grounded connected, so it’s more suitable to use with balanced active speakers." So does that mean I shouldn't use the 4.4mm balanced connectors on my IEM and should instead buy another 2.5mm balanced cable for IEM use? What exactly would be the problem if I plugged my IEM into the 4.4mm balanced input?
There is no difference between them with respect to headphone listening since your headphones are not referenced to ground. Either connection works fine. Indeed I tested using 4.4 mm jack.
 
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amirm

amirm

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So this sounds perfect for IEMs which are sensitive - I just bought it for my IEM plugged into my Macbook Air! Wait... it is compatible with the Mac OS right?
It should be. The class driver worked on Windows and Mac has the same thing.
 
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