Do you reckon this board would be good?
https://www.ebay.com/itm/283975094118
The idea is to use it as a part of a preamp I'm building. I've been very happy with the sound quality of the Fiio BTA30, which has the same Bluetooth chip. I don't know the rest of the insides of the Fiio, though, so I don't know if expecting similar sound quality from a board like this is in any way realistic?
https://www.ebay.com/itm/283975094118
The idea is to use it as a part of a preamp I'm building. I've been very happy with the sound quality of the Fiio BTA30, which has the same Bluetooth chip. I don't know the rest of the insides of the Fiio, though, so I don't know if expecting similar sound quality from a board like this is in any way realistic?
I see a board on ebay with the newer QCC5125 and ES9038Q2M for around the same price, but it doesn't have the USB DAC function...
https://www.ebay.com/itm/174700531341
https://www.ebay.com/itm/174700531341
Thank you, good find! Missing the USB is no problem. It will be necessary to have another DAC unit in the preamp anyway, but it should have optical input as a must, USB nice but not necessary. Any suggestions? Perhaps something like this? https://www.audiophonics.fr/en/diy-...ical-coaxial-32bit-384khz-dsd256-p-12557.html
What should the expectation level be with these Chinese boards? A total crap shoot? According to this the DAC I linked might not be totally hopeless: https://www.audiosciencereview.com/...urements-of-generic-es9038q2m-dac-board.2408/
Funny that you mention these boards as I just purchased B2 Deluxe board in the newest version with Usb input. It can support 16bit 48kHz if the designers have used this function and not just usb for power. My board has better value with better dac and more inputs. I just hope the layout is good enough to avoid hiss. They also have more opamps on the dacs output, but I doubt they have proper IV implentation as recommended by ESS Sabre. But is should be decent. I plan to bypass the last op amp and run balanced mode straight into a cheap TPA3255 3e Audio clone board. I have already built a high end dac with the ES9038Q2M so I'm already familiar with modding this dac chip if hiss is a problem. The same board can also be found on Aliexpress.. https://www.ebay.com/itm/174698607022.
If you buy that DAC from audiophonics.fr, why not get the QCC5125 I2S module from them as well? Then you have one DAC with both BT and SPDIF. Seems like the best option to me.
https://www.audiophonics.fr/en/blue....html?search_query=QCC5125 I2S&fast_search=fs
Fair point, I had missed that. I guess the main challenge with that setup would originate from the fact that the plan is to put the DAC inside a preamp. Meaning I would need to be able to control the inputs from the preamp input selector, and won't be able to use the controls of the DAC. This means that I need two DAC's, unless I have a DAC that switches automatically to Bluetooth when a device is connected, and defaults to Toslink otherwise. I don't know if these are capable of doing that.
From the description of the DAC, you need to press and hold the MODE button to switch to the active input. A short press of the same button is mute function. Adding a simple momentary button to the front of the chassis seems like a simple thing, but I guess you are using some pre-fab chassis with a selector switch?
Well, no. I could implement a button like that, I suppose. I would like to keep things simple, though, as in one input selector and one volume control. I guess going for simplicity somewhere adds complexity elsewhere. 🙂
The shipping from EU or US to Norway is horrendous expensive, more like 30usd vs 5usd from China. So in practice that dac board from Audiophonics would be ca 70% more expensive. In some of the other listings of my suggestion it says BT takes priority atleast.. I plan to use an Alps pot on the analog in line and make a simple all in one unit in one box. I'm aiming for decent performance only and that dac board would probably sound slightly better. My pc's spdif is already in use to my headphone amp/dac so I'm left with usb for transfer.. I really hope the board pops up as a soundcard.
I'm very curious regarding the performance of this board.. Most china solutions have hiss problems and I wonder if the QCC5125 has analog passtrough or a AD converter inside?
I'm very curious regarding the performance of this board.. Most china solutions have hiss problems and I wonder if the QCC5125 has analog passtrough or a AD converter inside?
Yes, like another solution I thought of. You could use an I2S switch like this...
https://www.ebay.com/itm/174217739929
Connect a BT to I2S module on one input and an SPDIF to I2S module on the other, and then the output could go to any I2S input DAC of your liking. I don't know how you plan to do the preamp input switching, but if it's an electronic board with relays, you could use the relay signal from the source selection for the BT or SPDIF to power another relay to toggle the I2S switch. A little confusing, but really not all that complicated. Just a lot more wiring going on.
I can’t speak for the sound quality of these Bluetooth DACs, however, I wouldn’t mind comparing them to the $2 Bluetooth 5.0 boards that are based in the Jieli chips.
Keeping in mind that any Bluetooth is limited to 16/48, I have been fairly impressed with them when care has been taken for power supply and coupling parts, and the range nearly covers my entire house.
Some of my other equipment includes; Volumio/Asus Tinker Board with an ak4495 DAC that uses the akm demo board circuit, with modified power supply, Burson op amps; WM8741 DAC using the Arcam circuit, lots of power supply mods, Burson op amps.
Keeping in mind that any Bluetooth is limited to 16/48, I have been fairly impressed with them when care has been taken for power supply and coupling parts, and the range nearly covers my entire house.
Some of my other equipment includes; Volumio/Asus Tinker Board with an ak4495 DAC that uses the akm demo board circuit, with modified power supply, Burson op amps; WM8741 DAC using the Arcam circuit, lots of power supply mods, Burson op amps.
Interesting idea! I'm going to use the Salas I-Select for input selection, so it is a relay-based concept like you described. Using relays to change the input of the DAC like you said would actually be a rather nice solution. I don't have the exact wiring needed to accomplish this clear in my mind yet, but I'm sure something like this could work. Thanks for bringing that up!
Yeah that's a pretty hefty shipping cost, for us its 6€. I'm somewhat worried about potential hissing or other problems as well, which is why I'm also a bit hesitant about these boards. If I could find a proven solution with a bit more money, I would rather go with that. Not being familiar with the scene, I haven't really found many DIY solutions that would fit the bill, so unless that changes a proven solution for me would mean taking a commercial product and repurposing that.
For example, I have a Fiio BTA-30 and a Schiit Modi that I know work fine and deliver a sound quality that I'm personally happy with. I could just put them inside the preamp and be done with those parts of the build. But, to me that seems like a bit of a waste of perfectly good stand-alone products, and I would rather not disassemble them but keep them in working condition for other purposes. My assumption is also that by buying a board or DIY kit I should be able to get similar quality levels with less expense, or higher quality with similar expense, compared to the ~300€ total what the two commercial units are combined.
If you don't plan on using all 6 inputs of the board, one could be used to toggle the I2S switch. That would really simplify things. Just connect two of the relay coils to the same pole on the selector switch. One of the relays would be for the actual audio signal of the BT or SPDIF, and the other relay to toggle the I2S switch.
On second thought, that would probably require cutting some traces on the board. Probably best to just use a separate relay.
The usual problem with cheap bt amp board is ground loop noise inside the board ground layer. Putting on external psus on the different chips usually removes the hiss. So if there is a hiss problem I'll just add small dual voltage trafos and voltage regulators on each chip. That gives huge sound benefits aswell. Changing voltage dividers on the analog signal line also helps in certain cases. Increasing cap size on the psu side doesnt affect hiss as some people belive. I just hope the board is good enough stock so I can recommend it to others aswell.
A quick follow up on my dac/bt board: It works well and has decent output volume and the sound seems very good on usb. It does not use usb for power and shows up as a 24bit 96kHz with native windows support. I paired it with a cheap china tp3255board and got way to much gain so the output signal is decent. It did not come with a 5V adaptor so thats a bummer. Running separate psu for dac and amp there is no ground noise or other problems 🙂
It looks to me that the op amps creates a virtual ground for the dac chip!! Most cheap solutions just run regular voltage gain wich lowers performance so seeing this done right is a huge pluss. (I might be wrong here but following the traces it looks like the IV part is done right).
I cant test the LDAC but regular BT sounds fine.
One let down is no analog in. I havent found out what the button does either so please tell me if you find out 😉 The board is easy to mod so I added few small caps here and there around the opamps just for kicks 🙂 I'm quite happy with this litte unit and so far I havent found any reason not to recommend it.
It looks to me that the op amps creates a virtual ground for the dac chip!! Most cheap solutions just run regular voltage gain wich lowers performance so seeing this done right is a huge pluss. (I might be wrong here but following the traces it looks like the IV part is done right).
I cant test the LDAC but regular BT sounds fine.
One let down is no analog in. I havent found out what the button does either so please tell me if you find out 😉 The board is easy to mod so I added few small caps here and there around the opamps just for kicks 🙂 I'm quite happy with this litte unit and so far I havent found any reason not to recommend it.