This is a review and detailed measurements of the HDPlex 200 watt linear, multi-voltage power supply. It is on kind loan from a member. The 200W costs US $485 from the company.
The enclosure is small but impressively hefty and quality feeling:
As you see, there are no controls or indicators in the front. The business end is the back:
I was pleased to see so many concurrent outputs with two of them fixed and two programmable. For my testing, I only used the 5 volt output to power USB based DACs.
Use of an XLR connector is a bit unusual but is fine if one wires it up with heavier gauge wires. One adapter came with the unit that went from XLR female to 9 volt plug. That allowed me to test the unit with Topping D50. I also tested the 200W with Schiit Modi 3 DAC which requires a micro-USB cable. I managed to build an adapter to power that.
I wanted to test the 200W with my two best performing headphone amplifiers but could not. The JDS Labs Atom needs AC input and the voltage requirement for Massdrop THX AAA 789 was too high for the HDPlex 200W.
I see the list of regulatory certifications. Hopefully they are real and not just stamped on the unit.
The company provides pictures of the insides and it seems tidy and nice:
Measurements
As noted, I focused my testing on DACs that are USB powered. There always seems to be anxiety with regards to power coming out of a PC being "too dirty" to power a DAC. We have explained many times that the power is not used as is. Rather, the USB power is filtered and often converted to another voltage before use. But audiophiles persist and want to use linear power supplies anyway. So let's start with Topping D50, running a 1 kHz tone FFT spectrum to see if either distortion, spurious tones, or noise floor changes with different methods of powering the unit. I used a wide bandwidth way beyond our hearing range so there is no criticism of cleaner spectrum above hearing range. Here is the three-way comparison:
The baseline in orange is a little external USB charger adapter. Red uses the PC power supply and green is with HDPlex. If I were to squint, there seems to be a bit less random junk in there around 10 kHz compared to USB Power. But we are talking about levels well below -130 dB. With our best case hearing dynamic range being 116 dB or so, no way this is material.
Above is with USB audio input by the way. Schiit Modi 3 DAC powers itself from the USB data jack so I could not test it the same way. Instead, I used S/PDIF coax input when forced the DAC to power itself from the secondary USB jack. Here are the same three tests:
The USB adapter this time is a beefy 3 amp switching supply I use for testing streamers. The other two are USB power and HDPlex as before. This time I can't see any difference even if I squinted. Whatever is wrong here is the fault of the S/PDIF input on the Schiit Modi 3, not anything to do with how it is powered.
I want to make sure you all note that these are highly sensitive measurements. Through power of signal processing, we have a measurement noise floor of -150 dB. That is insanely low levels and hence the reason we can see tiny spikes deep inside the noise floor. Hearing some of these noise spikes would be akin to you hearing me flush the toilet at our house.
It ain't going to happen!
Conclusions
The HDPlex 200W has a very quality feel to it with seemingly good choice of components. Price of nearly US $500 while somewhat high, is not really out of the range of what something like this could sell for. The issue is that such power supplies are a solution looking for a problem. Yes, our audio devices have incredibly high precision. Engineers know how to design power supplies for them that achieve that precision with no external help. The power is already cleaned internally because external power is assumed to not be so. No wonder then that adding a different power supply makes no difference.
So please put aside your intuition in judging such products. When even a $99 DAC shows no improvement with a power supply that costs $500, you should be on notice that there is no there there. If you spend thousands of dollars for your DAC and assumed its designer is even less competent, you really are leaving common sense at the door.
I read that people are hooking these up to their routers, computers, etc. Man, what a waste of money and electricity.
"Good news" is that nothing got worse by using HDPlex. So no harm is done.
Needless to say, I can't recommend this power supply as an audio tweak.
----------------------
Questions, comments, critique, etc. are welcome.
I want to go on a low-carb diet. Problem is, I can't cut back on bread, rice and grains as I love eating them. My solution is to heavily increase my intake of meat so the ratio works out! Alas, good steaks cost money so please, help me with my diet by donating generously 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).
The enclosure is small but impressively hefty and quality feeling:
As you see, there are no controls or indicators in the front. The business end is the back:
I was pleased to see so many concurrent outputs with two of them fixed and two programmable. For my testing, I only used the 5 volt output to power USB based DACs.
Use of an XLR connector is a bit unusual but is fine if one wires it up with heavier gauge wires. One adapter came with the unit that went from XLR female to 9 volt plug. That allowed me to test the unit with Topping D50. I also tested the 200W with Schiit Modi 3 DAC which requires a micro-USB cable. I managed to build an adapter to power that.
I wanted to test the 200W with my two best performing headphone amplifiers but could not. The JDS Labs Atom needs AC input and the voltage requirement for Massdrop THX AAA 789 was too high for the HDPlex 200W.
I see the list of regulatory certifications. Hopefully they are real and not just stamped on the unit.
The company provides pictures of the insides and it seems tidy and nice:
Measurements
As noted, I focused my testing on DACs that are USB powered. There always seems to be anxiety with regards to power coming out of a PC being "too dirty" to power a DAC. We have explained many times that the power is not used as is. Rather, the USB power is filtered and often converted to another voltage before use. But audiophiles persist and want to use linear power supplies anyway. So let's start with Topping D50, running a 1 kHz tone FFT spectrum to see if either distortion, spurious tones, or noise floor changes with different methods of powering the unit. I used a wide bandwidth way beyond our hearing range so there is no criticism of cleaner spectrum above hearing range. Here is the three-way comparison:
The baseline in orange is a little external USB charger adapter. Red uses the PC power supply and green is with HDPlex. If I were to squint, there seems to be a bit less random junk in there around 10 kHz compared to USB Power. But we are talking about levels well below -130 dB. With our best case hearing dynamic range being 116 dB or so, no way this is material.
Above is with USB audio input by the way. Schiit Modi 3 DAC powers itself from the USB data jack so I could not test it the same way. Instead, I used S/PDIF coax input when forced the DAC to power itself from the secondary USB jack. Here are the same three tests:
The USB adapter this time is a beefy 3 amp switching supply I use for testing streamers. The other two are USB power and HDPlex as before. This time I can't see any difference even if I squinted. Whatever is wrong here is the fault of the S/PDIF input on the Schiit Modi 3, not anything to do with how it is powered.
I want to make sure you all note that these are highly sensitive measurements. Through power of signal processing, we have a measurement noise floor of -150 dB. That is insanely low levels and hence the reason we can see tiny spikes deep inside the noise floor. Hearing some of these noise spikes would be akin to you hearing me flush the toilet at our house.
It ain't going to happen!Conclusions
The HDPlex 200W has a very quality feel to it with seemingly good choice of components. Price of nearly US $500 while somewhat high, is not really out of the range of what something like this could sell for. The issue is that such power supplies are a solution looking for a problem. Yes, our audio devices have incredibly high precision. Engineers know how to design power supplies for them that achieve that precision with no external help. The power is already cleaned internally because external power is assumed to not be so. No wonder then that adding a different power supply makes no difference.
So please put aside your intuition in judging such products. When even a $99 DAC shows no improvement with a power supply that costs $500, you should be on notice that there is no there there. If you spend thousands of dollars for your DAC and assumed its designer is even less competent, you really are leaving common sense at the door.
I read that people are hooking these up to their routers, computers, etc. Man, what a waste of money and electricity.
"Good news" is that nothing got worse by using HDPlex. So no harm is done.
Needless to say, I can't recommend this power supply as an audio tweak.
----------------------
Questions, comments, critique, etc. are welcome.
I want to go on a low-carb diet. Problem is, I can't cut back on bread, rice and grains as I love eating them. My solution is to heavily increase my intake of meat so the ratio works out! Alas, good steaks cost money so please, help me with my diet by donating generously 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).
