This is a Review and Measurement of Cheap Ebay CM108 Bare Board USB DAC. There are a number of these with the cheapest one retailing for just USD $8 (https://www.ebay.com/itm/CM108-TDA1...833370?hash=item467db6a85a:g:9hwAAOSwkJZbEbqj). It is part of a collection of USB dacs to test from a kind member.
Here is what it looks like:
The white solder mask saves the thing from looking crusty and cheap. Let's see how it measures.
Measurements
Starting with our dashboard we see this:
Distortion is about 100 times worse than the best products we test. Admittedly this is at max volume (but with 100 kohm load). Still, we are talking bottom of the barrel performance here.
Of note, the frequency counter was jumping up and down. Likely due to use of adaptive USB mode instead of async interface. FFT shows high noise floor and lots of distortion spikes.
Quick look at distortion versus output level produces this:
We see that the performance at 300 ohm load in red is all over the place. Good news there is that it doesn't really clip. It simply stops getting louder.
At 33 ohm, things calm down but at pretty high distortion levels until hard clipping at 1 volt output.
Didn't bother testing more as it is clear there are a lot of performance issues here.
Listening Tests
Quick listening test shows modulated bass frequencies and oddest response. It almost sounds like the output is run through a synthesizer in each bass note. All of this may be in my head, but I think it got there through my ears.
Conclusions
You all know that I am always on a hunt for a bargain product that performs excellently. Alas, this one isn't. Definitely NOT recommended.
If you want something cheap, the Speak DAC and its clone are the way to go at $30 or so. See https://audiosciencereview.com/foru...-speaka-usb-dac-and-headphone-amplifier.2423/
As always, questions, comments, corrections, jokes, etc. are all welcome!
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If you like this review, please consider donating funds for these types of hardware purchase 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).
Here is what it looks like:
The white solder mask saves the thing from looking crusty and cheap. Let's see how it measures.
Measurements
Starting with our dashboard we see this:
Distortion is about 100 times worse than the best products we test. Admittedly this is at max volume (but with 100 kohm load). Still, we are talking bottom of the barrel performance here.
Of note, the frequency counter was jumping up and down. Likely due to use of adaptive USB mode instead of async interface. FFT shows high noise floor and lots of distortion spikes.
Quick look at distortion versus output level produces this:
We see that the performance at 300 ohm load in red is all over the place. Good news there is that it doesn't really clip. It simply stops getting louder.
At 33 ohm, things calm down but at pretty high distortion levels until hard clipping at 1 volt output.
Didn't bother testing more as it is clear there are a lot of performance issues here.
Listening Tests
Quick listening test shows modulated bass frequencies and oddest response. It almost sounds like the output is run through a synthesizer in each bass note. All of this may be in my head, but I think it got there through my ears.
Conclusions
You all know that I am always on a hunt for a bargain product that performs excellently. Alas, this one isn't. Definitely NOT recommended.
If you want something cheap, the Speak DAC and its clone are the way to go at $30 or so. See https://audiosciencereview.com/foru...-speaka-usb-dac-and-headphone-amplifier.2423/
As always, questions, comments, corrections, jokes, etc. are all welcome!
----
If you like this review, please consider donating funds for these types of hardware purchase 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).