Thank you, sir.
In case anyone is interested in how Topping chose to implement D90, the four regulators (along with 4 Nichicon FW electrolytics, and a few SMD ceramics) power VREFHxx and VDDxx, 2-channels per regulator (dac channels are summed in pairs after I/V to end up with stereo out).
Exactly the same part used in Topping Dx3pro powering AK4493. 10x worse noise spectral density than LT3042. Considerably worse PSRR and load transient response. Are these for Vref in D90 indeed?
Sure looks like it, unless some other regulator comes in the same package and has the same SMD marking code.
Then again, its a commercial dac that has to sell for under $700. The total price of all the parts including the multilayer PCB, the case, shipping box, accessories, etc., all has to cost only a fraction of the selling price of the unit.
It sounds very good indeed for the price (compared to what some other dacs cost). Its just not the very best of what AK4499 is capable of.
EDIT: All the foregoing IMHO only!
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What I find interesting with the D-90 is that despite the necessarily compromised build quality, the measurements are outstanding for both noise and distortion. Very close to as good as it gets on standard measures, including multi-tone testing. After some level matched comparison with my ESS 9038 DIY DAC (Buffalo PRO with Mercury, with power supplies of my own design), I sold the D-90: it did some things better than the BuffPRO, but lacked a bit in body, presence, and dynamics: these are all sonic qualities which I often associate with power supply implementation (among other things). Of course this was hardly a fair fight: just a single transformer (of two) from my BuffPRO build weighs more than the entire D-90 DAC.
I must say, I am very, very impressed by what I think the AKM 4499 is capable of (especially in DSD direct mode), and will be looking for a suitable DIY approach to this chip going forward. (I am not capable of, nor should I attempt, a high speed DAC PCB design myself).
I must say, I am very, very impressed by what I think the AKM 4499 is capable of (especially in DSD direct mode), and will be looking for a suitable DIY approach to this chip going forward. (I am not capable of, nor should I attempt, a high speed DAC PCB design myself).
well, ADP7112ACBZ would be about 1€ in contrast to 2.7€ for LT3042, but the latest will need more parts around.
still I think that Toping is somehow recycling design fragments. for instance this is the case comparing their es9018k2m and es9028q2m dacs.
so, I would not be surprised in order to quickly release the product many things are copy-pasted. for the first time I saw this tiny reg in Dx3pro, it is also present in D70. not sure, whether it powers Vref there (U4 in the pic attached).
nowadays the gap between measurement and sounding is widening indeed. 120€ worth Topping E30 (AK4493) measures excellent but the sound is average at best. IMHO of course
still I think that Toping is somehow recycling design fragments. for instance this is the case comparing their es9018k2m and es9028q2m dacs.
so, I would not be surprised in order to quickly release the product many things are copy-pasted. for the first time I saw this tiny reg in Dx3pro, it is also present in D70. not sure, whether it powers Vref there (U4 in the pic attached).
nowadays the gap between measurement and sounding is widening indeed. 120€ worth Topping E30 (AK4493) measures excellent but the sound is average at best. IMHO of course
Attachments
Mark,
What Camera did you use to take the Macro picture of the Regulator?
Its VERY decent Zoomed Photo
That certainly appears to be the case based on what people post in this thread.
A slightly modified version of: Amazon.com: Andonstar 5 inch Screen 1080P Digital Microscope HDMI Microscope for Circuit Board Repair Soldering Tool ADSM302: Camera & Photo
Also, used some contrast (gamma) enhancement on the regulator to make the marking codes easier to read.
So you mean one regulator powers the left and right channel vref of DAC1, one powers the left and right channel vref of DAC2. Then one does vdd for the left and right channel of DAC1 and the last vdd for the left and right channel of DAC2?
That, or to similar effect. It may be that one powers both left channels, and one powers both right. Didn't check the exact pairing.
Sounds like a good idea - can you confirm the exact fuse spec for the D90?
Many thanks
Please provide a link to the kit you found on aliexpress.
Have you built a dac kit before? Know how to make it work?
Dual AK4497 AK4497EQ AKM HIFI DAC DSD Decoder XLR DAC+ Bluetooth 5.0 CSR8675 APTX HP
Dual AK4497 AK4497EQ AKM HIFI DAC DSD Decoder XLR DAC+ Bluetooth 5.0 CSR8675 APTX HP|Digital-to-Analog Converter| - AliExpress
This is not exactly a kit.
Dual AK4497EQ DAC AK4118 DAC decoder CSR8675 Bluetooth 5.0 support APTX HD DSD Coaxial fiber Input T0656|Digital-to-Analog Converter| - AliExpress
Dual AK4497 AK4497EQ AKM HIFI DAC DSD Decoder XLR DAC+ Bluetooth 5.0 CSR8675 APTX HP|Digital-to-Analog Converter| - AliExpress
This is not exactly a kit.
Dual AK4497EQ DAC AK4118 DAC decoder CSR8675 Bluetooth 5.0 support APTX HD DSD Coaxial fiber Input T0656|Digital-to-Analog Converter| - AliExpress
Those dac boards look like some of the better Chinese variants. They are made for use with an Amanero USB board. Only a real Amanero, not a Chinese clone like on Aliexpress, supports ASIO drivers in Windows and Native DSD. Unfortunately, even real Amanero boards do on have great clocks or galvanic isolation. Much better IMHO is JL Sounds I2SoverUSB, although it won't directly plug into the USB board socket on the dac board. Whatever clocks are on the USB board will do a lot to define the jitter the dac chip will see, it it will affect sound quality.
Also, something to know about most of the dac boards coming out of China is that the dac chip is usually the only genuine part. Capacitors and resistors in particular are generally cheap clones despite the brand names on the labels. Similar in many cases for opamps, depending on the cost of a genuine article.
Another thing to know is that dacs are sensitive to power supply quality, particular the output stage reference supply, but the other dac power pins have some effect too on ultimate sound quality too. A cheap regulator, especially with mixed load types on a single regulator, very commonly has an adverse effect on sound quality.
Even with cheap parts and jittery clocks, frequency response should be flat, and stationary harmonic distortion spectrums may look okay. Many have found there are audible effects from dacs that do not always show up on basic tests that usually work better for things like amplifiers that don't mix digital, RF, and analog all in the same chip. Just sayin'
Some people are bothered by small-ish defects in sound quality and other people don't notice them at all. Varies a lot from person to person just the way it is.
So, the dac board may sound very much to your satisfaction more or less as-is, or some modding work might be in your future if you were hoping for better.
Also, something to know about most of the dac boards coming out of China is that the dac chip is usually the only genuine part. Capacitors and resistors in particular are generally cheap clones despite the brand names on the labels. Similar in many cases for opamps, depending on the cost of a genuine article.
Another thing to know is that dacs are sensitive to power supply quality, particular the output stage reference supply, but the other dac power pins have some effect too on ultimate sound quality too. A cheap regulator, especially with mixed load types on a single regulator, very commonly has an adverse effect on sound quality.
Even with cheap parts and jittery clocks, frequency response should be flat, and stationary harmonic distortion spectrums may look okay. Many have found there are audible effects from dacs that do not always show up on basic tests that usually work better for things like amplifiers that don't mix digital, RF, and analog all in the same chip. Just sayin'
Some people are bothered by small-ish defects in sound quality and other people don't notice them at all. Varies a lot from person to person just the way it is.
So, the dac board may sound very much to your satisfaction more or less as-is, or some modding work might be in your future if you were hoping for better.
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What do you recommend any dac “kit” with ak chip ?
I’m not experience in dac but I’m looking a micro detail of dac.
Ak4499 is my best opinion, but I can not choose which kit to build.
My goal is micro detail dac .
I hope anyone Here knows where to build one.
I can not find anyone bought the dac on aliexpress and review.
I’m not experience in dac but I’m looking a micro detail of dac.
Ak4499 is my best opinion, but I can not choose which kit to build.
My goal is micro detail dac .
I hope anyone Here knows where to build one.
I can not find anyone bought the dac on aliexpress and review.
Don't know of any AK4499 kits. AK4497 is the closest I have seen. I would suggest to study the AK4497 data sheet, and if you can find it, an AK4497 evaluation board schematic (should be in the evaluation board manual/datasheet document). That's what AKM recommended as a starting point. Then compare that to what you in the pics at Aliexpress or Ebay. Not the same, I'll bet. That might give you idea of the direction you would likely go if you wanted to modify a Chinese board. Just my opinion, of course. Others surely will have some other ideas.