Topping D50

[wwmhf]

D50 is a decent DAC, but I will not venture to try that DAC listed on ebay.

 

[carlmart]

A very good point.

 

[carlmart]

Continuing the D50 internal power supply upgradings, for those that are willing to go that path, perhaps this might be a good start:

https://www.ebay.com/itm/HIFI-DAC-D...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I already bought it some time ago, to try it on another DAC. I am not sure how many voltages the D50 needs, but the board has three trimmers, so you just input the closer unregulated voltage you need, and then trim it.

Usually you shouldn't need more than 3-4v more, DC in that is. On this board you input AC voltage, remember that.

Unfortunately there's no space inside the D50 to put this board inside, so some thinking on how to wire it is in order.

You will also need separate transformers for each AC voltage.

 

[439598]

Continuing the D50 internal power supply upgradings, for those that are willing to go that path, perhaps this might be a good start:

https://www.ebay.com/itm/HIFI-DAC-Dual-Supply-Pure-Class-A-Parallel-Dual-Supply-12V-5V-for-PCM1794/272627899831?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I already bought it some time ago, to try it on another DAC. I am not sure how many voltages the D50 needs, but the board has three trimmers, so you just input the closer unregulated voltage you need, and then trim it.

Usually you shouldn't need more than 3-4v more, DC in that is. On this board you input AC voltage, remember that.

Unfortunately there's no space inside the D50 to put this board inside, so some thinking on how to wire it is in order.

You will also need separate transformers for each AC voltage.

here is a good picture of the PCB.

There are multiple 3.3V converters providing power to the main important areas.
''USB3.3V'' for the XMOS chip. ''VCC33DAC'' and the ''VCC33L'' and ''VCC33R'' are probably all for the DAC chips, im not sure why there is 3.

The other converters must be for the display and controls, easy to keep using the 5V input for this.
I wonder how good this DAC will become with all of these areas externally powered aswell, endgame for sure.

 

[carlmart]

Which are the 0 ohm resistors?

What is the output chips PS voltage? I guess they are those three on the upper right.

It would be great to get a service manual. Probably unavailable.

 

[jacken]

Yes, the D50 internal supply is a switching type, instead of linear, and I believe it might be a bottleneck.

It's the price you have to pay to use power through the USB interface, or even feeding one single supply through the power socket.

This has to be stepped up to the different voltages inside. You need DC-DC switching for that.

It looks like they're using ADP151 linear voltage regulators to drive the DAC at least. They have 9 µV RMS output noise, so very quiet. I've used them in several projects and are excellent.
I'm getting mine D50 tomorrow and will do measurements with different power supplies to see if there's a difference.

 

[carlmart]

A linear regulator fed by a switch supply would still keep the noise, woildn't it?

Actual measurements would be a very good thing.

 

[jacken]

A linear regulator fed by a switch supply would still keep the noise, woildn't it?

Actual measurements would be a very good thing.

I need to get a closer look at the circuit board, but I've seen measurements at https://www.audiosciencereview.com/...iew-and-measurements-of-topping-d50-dac.2403/
He has an Audio Precision Audio analyzer which is standard in the industry and after reading a lot of his reviews, I've concluded that he knows how to use it as well.
In the measurements, it doesn't seem too sensitive to a noisy power supply. I find it funny that a lot of people talking about getting a power bank to power it. There you have a buck and/or boost switching regulator with a lot of noise. The batteries are not connected directly.

I'll use my audio analyzer and do some measurements with different power supplies just for kicks.

 

[wwmhf]

I agree with Jacken's comments on power/battery banks: they use regulators. Some power/battery bank use good one, some of them use just junks.

I am very interested in your measurements about different power supplies. Those measurements can be valuable because they will shed some light on modding D50 and other DACs.

 

[jacken]

I agree with Jacken's comments on power/battery banks: they use regulators. Some power/battery bank use good one, some of them use just junks.

I am very interested in your measurements about different power supplies. Those measurements can be valuable because they will shed some light on modding D50 and other DACs.

I've been down the road of modding DACs and headphone amplifiers. But after working on a new headphone amplifier design for the last year and a half, I've come to the conclusion that the best thing is to get the DAC and amplifier to be as transparent as possible. As long as the DAC + amplifier is not distorting the sound, you can easily just try different headphones. You're feeding a signal with (hopefully) a linear frequency response that has a THD of 0.001% into a resistive/capacitive load that is around 0.1% THD, aka the headphone. As long as the amplifier is able to drive them to an acceptable level, without adding distortion, you're all good. I know that it's fun to try to improve on a design, but my skin crawls when I see people recommend to replace a JFET op-amp with a bipolar or vice-versa. They all have their uses, but just mix and match in a well-designed construction is doomed to fail. Yeah, sometimes the design skimps on quality components, but isn't it time then, to consider a better manufacturer?

 

[carlmart]

Already received the eBay triple discrete regulator I showed above. It looks extremely good.

It might be a Sulzer/Jung regulator, but I will have to back-engineer it to check that. The active parts are a 5534 chip and an IRF9z34ns mosfet.

As mentioned, the board can't fit inside the D50, but it could be used as pre-regulator, and inside put these very low noise regulator boards.

https://www.ebay.com/itm/NEW-LT3042...m=273013276211&_trksid=p2047675.c100752.m1982

But first I would try the regulator board I got direct.

 

[andrewinukm]

Wow! Finally some mods on the D50!

Good job guys. Too bad I'm not much of an engineer, so I'll have to follow what you guys have discovered.

 

[Faber65]

Last weekend at the CanJam in Shanghai, I had the opportunity to test the D50, together with the new siblings A50 and P50 (coming soon).
I carried with me my beloved MrSpeakers Aeon Flow C and I must say that I was positively impressed about the SQ for the money.

I know that SQ is a very personal thing and IMHO the guys at Topping did another pretty damn good job.

Probably the new P50 Power Linear Supply unit is what many of us were looking for.

 

[spacequeen7]

What are the specs on that "A50" ?

 

[Faber65]

Not sure, the few info were on the small tag beside of the amp, and I did not take the picture.
As far as I remember it has two gain options: 0 and 9 dB.
6,5 and 3,5mm SE output and the 2,5mm balanced output.
1W output on 16 Ohm.
Nothing more, but let me ask.... maybe the sales guys have more info to share.