This is a surprise for me... It looks like a toy but it's not. This little plastic DAC has surprisingly good meaty bass. The composition of the sound here is different from PCM... it has a different balance as well as substance... it draws even more to the analog raw sound like a turntable. It deserves a decent better box.😎
It's a good DAC, I've made 5-6 of them so far for friends and familly. I'm building another one right now. 😎
That one was supposed to be mine as a spare DAC, for the closet, to use up the excess parts and try the Amanero USB/I2S copy. That's why I put it in that ugly box. It's a simple device.
And otherwise AD1865 has such a sound, warmer, more bass but less detail. For some it fits into the system, for some it doesn't.
That one was supposed to be mine as a spare DAC, for the closet, to use up the excess parts and try the Amanero USB/I2S copy. That's why I put it in that ugly box. It's a simple device.
And otherwise AD1865 has such a sound, warmer, more bass but less detail. For some it fits into the system, for some it doesn't.
It's a really great DAC. I'm pretty shocked—or, I had no proper frame of reference apparently for what a good DAC can be. It's not a vinyl killer (for me, I still perceive a definable edge in our system here—I won't attempt to define that with words other than that experience is just "even more" of everything)—but it's certainly the first DAC I've ever owned that I WANT to listen to that has a sense of space and whatever, again—subjective. That's VERY cool though and I love that it's so good and feel blessed to have made it. AD1865 next, after I finish the chassis for AD1862 (today).
To me, the AD1862 is better than the AD1865, but you'll hear it yourself when you put it together. It sounds more detailed but not quite like the PCM63 which puts out the most detail but is a bit thinner in the bass than all the others. I think PCM63 is ideal for tubes at the output. These OPA I/V variants are not as convincing sonically as tubes + PCM63.
All those DACs are really good sounding, even the cheap PCM56. I even like the AD1856 a bit more than the PCM56 and if it's the same chip formally. It's a bit brighter sounding, maybe that's why.
All those DACs are really good sounding, even the cheap PCM56. I even like the AD1856 a bit more than the PCM56 and if it's the same chip formally. It's a bit brighter sounding, maybe that's why.
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Couple of finish shots from the shop...Pretty basic, but clean...Nice to finally have a fully DIY system—nice nighttime glow...Might be fun to try it with the tube pre there at some point...
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The whole system looks very nice.
Just one note, the USB connector should not touch the chassis. The JLS board has galvanic isolation so that the PC GND does not mix with the DAC GND. Slightly widen the opening around the USB connector, 1-2mm is enough.
Another note on the note. If you have a too stiff USB cable, make sure it is fixed somewhere physically. I succeeded to bend the USB port on the JLS out of the place .😆
I used sommercable Cat.6 SC-MERCATOR CAT.6 as USB cable. 🤣
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I would prefer to use AD1862 chip.
Also plan to use JLsounds I2SoverUSB.
I'm going through a lot of reading on PSU and haven't decided anything. Between PSU1/PSU2/VRDN/L-adapter/etc. there seems to be an abundance of choice 🙂
Also plan to use JLsounds I2SoverUSB.
I'm going through a lot of reading on PSU and haven't decided anything. Between PSU1/PSU2/VRDN/L-adapter/etc. there seems to be an abundance of choice 🙂
PSU2 for sure.
No modifications are required to Miro AD1862 PCBs. Only OPAs are not installed, and the Iout signal is taken from the DAC chip and terminated to GND with a max 100ohm resistor for AD1862. You connect each OPA pin 2 (Iout) and pin 3 (GND) with 100ohm (or less) resistor, instead of R8 you install a jumper and you have voltage at the output.
This is how a passive I/V conversion is done and that voltage signal leads to the tube gain stage. A smaller I/V resistor is better, but you should take care that the current output of the AD1862 is only +-1mA peak, so accordingly you should have enough amplification in the tube stage. 100 ohms gives you 70mV RMS, that should be amplified to the desired level. For 2.1V RMS gain should be 30x.
AD1865 tolerates larger passive I/V resistors (200-300ohm). Iout is also +-1mA peak, so the tube stage can have a lower gain (10-15x) for 2.1VRMS at the output.
Higher passive I/V resistor = higher signal distortion. So the smallest possible values I/V resistors are recommended, but then you put the tube stage in an awkward position to have a high gain. Let's say 50ohm on AD1862 Iout to GND - 35mVRMS - gain 60x - 2.1VRMS output voltage.
What is the voltage gain of that one "tubes4hifi SP14" ?
No modifications are required to Miro AD1862 PCBs. Only OPAs are not installed, and the Iout signal is taken from the DAC chip and terminated to GND with a max 100ohm resistor for AD1862. You connect each OPA pin 2 (Iout) and pin 3 (GND) with 100ohm (or less) resistor, instead of R8 you install a jumper and you have voltage at the output.
This is how a passive I/V conversion is done and that voltage signal leads to the tube gain stage. A smaller I/V resistor is better, but you should take care that the current output of the AD1862 is only +-1mA peak, so accordingly you should have enough amplification in the tube stage. 100 ohms gives you 70mV RMS, that should be amplified to the desired level. For 2.1V RMS gain should be 30x.
AD1865 tolerates larger passive I/V resistors (200-300ohm). Iout is also +-1mA peak, so the tube stage can have a lower gain (10-15x) for 2.1VRMS at the output.
Higher passive I/V resistor = higher signal distortion. So the smallest possible values I/V resistors are recommended, but then you put the tube stage in an awkward position to have a high gain. Let's say 50ohm on AD1862 Iout to GND - 35mVRMS - gain 60x - 2.1VRMS output voltage.
What is the voltage gain of that one "tubes4hifi SP14" ?
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Thanks! Are there audible ramifications to/of this situation? This seems to be a very important detail… maybe it should be more prominent someplace in the thread?
A GND loop may or may not appear. It is better to prevent it at the start with some isolation or gap. Heat-shrink insulation around the connector can also be used.
How is the DAC supply grounded to that box? The box must be directly on safety GND as it is metal.
How is the DAC supply grounded to that box? The box must be directly on safety GND as it is metal.