Sure, i'll try without !
I'm still looking for wiring in balanced mode. Find this:http://www.diyaudio.com/forums/pass-labs/117444-xlr-pin-1-question-chassis-vs-circuit-ground-3.html
"An important issue occurs when using transformers for balanced use as opposed to electronic differential inputs. A transformer is only connected to pins 2 and 3 even if there is a center tap. The center tap should not be connected to pin 1. When you have a single transformer either at the send or receive end it will not work if either pin 2 or 3 is open at the other end.(simon 7000).
The Xlrs pin1 are grounded on my preamp, maybe a good idee to not connect it on the dac side ? (ground loop)
I'm still looking for wiring in balanced mode. Find this:http://www.diyaudio.com/forums/pass-labs/117444-xlr-pin-1-question-chassis-vs-circuit-ground-3.html
"An important issue occurs when using transformers for balanced use as opposed to electronic differential inputs. A transformer is only connected to pins 2 and 3 even if there is a center tap. The center tap should not be connected to pin 1. When you have a single transformer either at the send or receive end it will not work if either pin 2 or 3 is open at the other end.(simon 7000).
The Xlrs pin1 are grounded on my preamp, maybe a good idee to not connect it on the dac side ? (ground loop)
No, it's not a good idea not to ground pin 1 on both sides of the connection.
That doesn't mean that the center tap has to be connected to pin 1. Follow what the transformer manufacturer specifies.
The loop is formed in unbalanced connection when you connect the same ground point twice within the same box from different places.
On an unbalanced cable with two conductors and a shield you may leave the shield unconnected on one side, but there should always be two connectors soldered or one connector and a shield soldered on both ends.
That doesn't mean that the center tap has to be connected to pin 1. Follow what the transformer manufacturer specifies.
The loop is formed in unbalanced connection when you connect the same ground point twice within the same box from different places.
On an unbalanced cable with two conductors and a shield you may leave the shield unconnected on one side, but there should always be two connectors soldered or one connector and a shield soldered on both ends.
I'm very interested to this DAC & will buy it ASAP. But before doing that, is somebody kind enough to post the schematic, layout, etc. I know that some seller will send it after the purchase, but I want to have all the info prior to the purchase (just to start to list what other components I need to order to mod this thing).
thanks in advance...
thanks in advance...
Hello,
I have just ordered a CS8416 / AK4396 DAC kit (not assembled). While I am waiting for it to arrive, I am thinking about upgrading the 3.3V regs and using a LT1761 low noise reg at each power insertion as close to the relevant IC as possible. i.e. not use the LM117s.
LT1761 allow a maximum current draw of 100mA so I have been checking the current requirements of the receiver and DAC. The DAC is no problem. However, I am not so sure about the CS8146.
The datasheet DC electrical characteristics shows a maximum analog (VA) supply current of 9.5mA and digital (VD) of 23mA, both at at 192 kHz frame rate.
So, my question is whether I am correct in assuming that the maximum current draw is the 23mA for VD.
If so, the LT1761 will be quite comfortable. I am currently using a 3.3V LT1761 to feed an low jitter SMD XO that draws about 25mA and it runs just barely warm, provided it's V in is about 5V. With a suitable output cap, 150uF Oscon SEP for example, the output noise is less than 20uV, which is about half that of the LM117.
Joe
I have just ordered a CS8416 / AK4396 DAC kit (not assembled). While I am waiting for it to arrive, I am thinking about upgrading the 3.3V regs and using a LT1761 low noise reg at each power insertion as close to the relevant IC as possible. i.e. not use the LM117s.
LT1761 allow a maximum current draw of 100mA so I have been checking the current requirements of the receiver and DAC. The DAC is no problem. However, I am not so sure about the CS8146.
The datasheet DC electrical characteristics shows a maximum analog (VA) supply current of 9.5mA and digital (VD) of 23mA, both at at 192 kHz frame rate.
So, my question is whether I am correct in assuming that the maximum current draw is the 23mA for VD.
If so, the LT1761 will be quite comfortable. I am currently using a 3.3V LT1761 to feed an low jitter SMD XO that draws about 25mA and it runs just barely warm, provided it's V in is about 5V. With a suitable output cap, 150uF Oscon SEP for example, the output noise is less than 20uV, which is about half that of the LM117.
Joe
Thanks for your reply. You may well be right, but my recent experience with extensive upgrades to the power supply and regulators on my CD player's DAC and filter chips brought a general, albeit subtle, improvement.
I have all the parts to do the LT1761 regs and I am quite happy to invest the time and effort and to experiment.
So I am still looking for confirmation that I have read the datasheet correctly.
Joe
I have all the parts to do the LT1761 regs and I am quite happy to invest the time and effort and to experiment.
So I am still looking for confirmation that I have read the datasheet correctly.
Joe
If you are lifting the pins on the CS8416 and AK4396 at the VD and VA points and giving a regulator to each (4 regs) then it should be no problem current draw wise.
Make sure you return the ground of the regulators to the point on the PCB used by the existing regs, not some arbitrary close ground point near the chips.
Make sure you return the ground of the regulators to the point on the PCB used by the existing regs, not some arbitrary close ground point near the chips.
Thanks for your reply and advice.
When I was fiddling with LM3X7 adjustable regs I learnt about taking the ground from the the adjustment cap and resistor (Kelvin sense) direct to the ground pin of the chip. One of the participants on the Marantz CD63/73 mod thread, I think it was Andy Weekes, gave a little tutorial about that. I try to do it with all regulators now.
Guido Tent's capacitor bypass guide has similar advice about locating the bypass caps as close as possible to the chip's ground pin.
Joe
When I was fiddling with LM3X7 adjustable regs I learnt about taking the ground from the the adjustment cap and resistor (Kelvin sense) direct to the ground pin of the chip. One of the participants on the Marantz CD63/73 mod thread, I think it was Andy Weekes, gave a little tutorial about that. I try to do it with all regulators now.
Guido Tent's capacitor bypass guide has similar advice about locating the bypass caps as close as possible to the chip's ground pin.
Joe
It is the basis of local de-coupling. However, try it both ways if you are so inclined (and measure the results). I would bet the PCB designer did the job right, so I'd follow the grounding paths they put down. Grounding is quite complex and rarely as easy as simply dumping ground to the nearest connection next to the chip (IME).
By the way, if you are playing with 317 regs then try replacing the voltage divider resistors with a low value resistor (100R) on the output to adjust leg and put a zener diode from the adjust pin to ground to set the voltage. High frequency output impedance should drop significantly.
By the way, if you are playing with 317 regs then try replacing the voltage divider resistors with a low value resistor (100R) on the output to adjust leg and put a zener diode from the adjust pin to ground to set the voltage. High frequency output impedance should drop significantly.
salut Fmahia,
Could you please explain a little bit the improvement brings by VALAB DSIX module ? I'm interested to this module too (it's not expensive) but cannot find any info.
merci d'avance et bon journee...
I have a strange problem with my DAC, I am using it from the output of my miniDSP. When I use REW to measure my speakers, I get a strange clinking sound that seems to get higher in tempo the higher the frequency.
I have tried connecting it directly from the output of my pc to the DAC and then I don't have this clicking, but the same goes if I take the analoge outputs of my miniDSP the signal is also fine.
So the question is do I have a fault in my DAC or is there something with the signal of the miniDSP?
I have tried connecting it directly from the output of my pc to the DAC and then I don't have this clicking, but the same goes if I take the analoge outputs of my miniDSP the signal is also fine.
So the question is do I have a fault in my DAC or is there something with the signal of the miniDSP?
A quick reply to i2k92: I don't know more than what I've read in the seller text about the Valab DSIX board. It's a reclock board for the SPDIF signal. I've no mesurement of its real effect on the jitter but I can tell that it provide a really good improvement with my computer SPDIF out. The sound is really more detailed and the bass are very good.