I save a conversion. I've got no spdif out on my laptop so I'm using a USB converter which has 2 outputs : spdif and I2S. I take directly the I2S and link it drectly to the dac instead of converting the signal to spdif and then to I2S. That is what I want to do, but for the moment I use spdif and it is working.
ah i see, is there any quality differance between spdif/optical and usb or are they just digital signals so as good as each other?
I'm using the diyparadise one, it is in the diy module section and you have to solder averything by yourself exept the chips.
About the quality différence I don't know, I assume that it is the same as the signal is digital in every cases. I think you lose quality with the conversions more than with the format of your signal.
About the quality différence I don't know, I assume that it is the same as the signal is digital in every cases. I think you lose quality with the conversions more than with the format of your signal.
Can any one help with what size transformer this requires, was thinking of a 100va 2x16 volt? The psu board supply's + and - 12v and 6v to the dac
100VA is definitely overkill. The digital parts use < 100mA @ 3.3V and < 50mA @ 5V. Being generous, that's less than 1A @ 16V input, or 16VA. The opamp uses well under 100mA @ +/-12V, if you're even using it - 150mA at +/-16V for another 5VA. These numbers are very conservative, you'd be fine with a 25VA or 50VA trafo.
16V is probably a bit high too, but it's the most appropriate common voltage (or 2x15V).
16V is probably a bit high too, but it's the most appropriate common voltage (or 2x15V).
Spot on, Didnt think it would be very big but i wasnt sure how to work it out so i thought better safae than sorry, though thats just saved me £10!
Just chcked the shop, they only do 20va or 50va, 20va still fine yes?
Just chcked the shop, they only do 20va or 50va, 20va still fine yes?
Probably fine, but it may be loaded fairly heavily. If you want to know for sure, you can measure how much current the DAC draws at each voltage and we can work out how much power is being used. I suspect 20VA would be sufficient, but it's below my (conservative) estimate, so I'd rather measure to be sure.kanifee said:
___"The problem with this setup for 192KHz is that the DAC chip needs to be told whether you want it to work at ~44.1KHz, ~96KHz or ~192KHz, and the board isn't set up to detect that and inform the DAC. That's actually what the described mod does in fact, it allows the S/PDIF chip to tell the DAC it needs to run at 96KHz or 44.1KHz - but the S/PDIF chip unfortunately doesn't provide a similar output for 192KHz.
You could wire it with a switch and set it manually and it should work, or you could permanently set it for 192KHz (but this will prevent it from working at 44.1/48KHz, and probably for 96KHz too). This board can't work automatically detecting 192KHz."---
HI, I'm sorry if my questions will be too simple - how exactly can I set permanently for 192KHz ?
Thanks in advance.
Vaclavus
You could wire it with a switch and set it manually and it should work, or you could permanently set it for 192KHz (but this will prevent it from working at 44.1/48KHz, and probably for 96KHz too). This board can't work automatically detecting 192KHz."---
HI, I'm sorry if my questions will be too simple - how exactly can I set permanently for 192KHz ?
Thanks in advance.
Vaclavus
if i get rid of the on board output caps, am i right in assuming this will need rather small replacements. This iwll be feeding my headphone amp and will see a 50k pot.
suggests a value of under 1uf?
suggests a value of under 1uf?
crickey, reading that back you wouldnt know i was english!
Basically i am asking what size cap i will need to prevent any bass roll off. I will remove the output caps and jumper the pads, then hook up some output caps directly to the RCA connectors.
Basically i am asking what size cap i will need to prevent any bass roll off. I will remove the output caps and jumper the pads, then hook up some output caps directly to the RCA connectors.
adamus said:
1uF into 50k should be OK at the low end, but are you intending to take the output via the caps direct from the CS4397? If so, you will get some ultrasonic noise which may upset your amp and appear as hiss. I took a balanced output direct from the CS4397, but I added some passive HF filtering. That works well.
John
Disconnect CS4397 M2 (pin 4) from 3.3V and connect it to ground instead.vaclavus said:
To fit a switch, use a pull-up resistor and a switch to ground. If you fit switches to M2 and M4 you can choose any speed.
adamus said:
I based my arrangement on this: http://www.jensen-transformers.com/as/as093.pdf
Instead of the transformer you would have your volume control pot, and with series 1uF caps you don't need the offset circuit.
If you are going single-ended instead of balanced you could just try 250 Ohms and 1uF in series with the +ve output, followed by 2n2 cap to ground.
I have boxed this up in a temporary card board box.
Sound good... but when there is noise when turned up.
Its not typical white noise, more like a constant crackle if that makes sense.
Any ideas where to look? its not the opamp (swapped opamps and it remains).
Cheers
Adam.
Sound good... but when there is noise when turned up.
Its not typical white noise, more like a constant crackle if that makes sense.
Any ideas where to look? its not the opamp (swapped opamps and it remains).
Cheers
Adam.
actually, i think this is a ground loop manifesting itself as a slightly higher pitch sound to what i am used to with a loop.
I hate ground loops!
I hate ground loops!
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