Hey thanks Bill.
Pulled the up-sampling board out and could only get it to go upto 96Khz ?? and anything above would show a lock (relay opening) but no audio regardless of dip switch settings. I would have imagined that if the up-sampling board was doing 192-24 and I pulled the board (put jumpers in) then it sould have at leaste had the same result at 192-24 (if not better) however I'm getting nothing then. wondering if it could maybe be the small coax input filter?
Pulled the up-sampling board out and could only get it to go upto 96Khz ?? and anything above would show a lock (relay opening) but no audio regardless of dip switch settings. I would have imagined that if the up-sampling board was doing 192-24 and I pulled the board (put jumpers in) then it sould have at leaste had the same result at 192-24 (if not better) however I'm getting nothing then. wondering if it could maybe be the small coax input filter?
It's either the input wiring, the signal itself, or the 8416. I read somewhere that changing the coupling caps from .1uf to .01uf has a beneficial effect. I think I read that in the 8416 datasheet.
Also, the use of RCAs for SPDIF is not the right impedance spec. and might cause enough ghost reflections to screw up the transfer at the elevated sampling rate. I'm grasping at straws here, no direct experience, just what I've read. Changing to 75ohm BNC connectors would be a good idea anyway. Or even F connectors.
Anyway, the 4398 chip is off the hook if things were working ok with upsampling lesser signals to 192khz.
Also, the use of RCAs for SPDIF is not the right impedance spec. and might cause enough ghost reflections to screw up the transfer at the elevated sampling rate. I'm grasping at straws here, no direct experience, just what I've read. Changing to 75ohm BNC connectors would be a good idea anyway. Or even F connectors.
Anyway, the 4398 chip is off the hook if things were working ok with upsampling lesser signals to 192khz.
I noticed that Decware is now selling it's own "Zen DAC ZDAC-1".
What's interesting is that looking at the shot of the innards from the DAC's online manual it looks to be nothing more than a Gigaworks DAC with an R-core transformer and a few upgraded parts, stuffed in a rather ordinary looking case and priced at a ridiculous US$875!
Here's the interior of the DAC:
Link to the DAC product page: Audiophile Tube Amps and Tube Gear from DECWARE
After reading the following blurb on the product page,
I've long known there is plenty of snake-oil going around in the high-end audio industry but I hadn't imagined Decware as a guilty party.
What's interesting is that looking at the shot of the innards from the DAC's online manual it looks to be nothing more than a Gigaworks DAC with an R-core transformer and a few upgraded parts, stuffed in a rather ordinary looking case and priced at a ridiculous US$875!
Here's the interior of the DAC:
An externally hosted image should be here but it was not working when we last tested it.
Link to the DAC product page: Audiophile Tube Amps and Tube Gear from DECWARE
After reading the following blurb on the product page,
for what to me seems to be basically a Gigaworks DAC with upgraded caps & op-amps, it's difficult not to reach the conclusion that Decware may be attempting to take advantage of it's customers.
I've long known there is plenty of snake-oil going around in the high-end audio industry but I hadn't imagined Decware as a guilty party.
Hey guys,
There are two resistors (I think? picture is blurry) missing from my newly arrived big DAC.
What exactly are these, and why were they removed?
I probably wouldn't think much of it, but they were literary clipped off my board. Parts of the leads are still there.
Also, is there any documentation on the DIP switches on the DAC PCB?
The documentation that was included is confusing as hell.
I'll make a drawing up in a sec that exhibits what I think might be correct, and you guys can confirm.
There are two resistors (I think? picture is blurry) missing from my newly arrived big DAC.
What exactly are these, and why were they removed?
I probably wouldn't think much of it, but they were literary clipped off my board. Parts of the leads are still there.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Also, is there any documentation on the DIP switches on the DAC PCB?
The documentation that was included is confusing as hell.
I'll make a drawing up in a sec that exhibits what I think might be correct, and you guys can confirm.
I am having problems with pops and clicks.
And every so often one or both channels will start artifacting/hissing until I stop and start the song. (I think foobar restarts the sound connection or something)
I thought it might be oscillations, but I put the stock opamps back in, and it still does it.
I am now wondering if the USB could be the culprit, but I don't have anything else to try.
I've tried with and without upsampling.
and, with quad and double enabled (w/o upsampling)
It doesn't work at all with either of the single settings.
Does anyone have any ideas?
And every so often one or both channels will start artifacting/hissing until I stop and start the song. (I think foobar restarts the sound connection or something)
I thought it might be oscillations, but I put the stock opamps back in, and it still does it.
I am now wondering if the USB could be the culprit, but I don't have anything else to try.
I've tried with and without upsampling.
and, with quad and double enabled (w/o upsampling)
It doesn't work at all with either of the single settings.
Does anyone have any ideas?
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Strange, the problem went away after took it off as my default sound card. (and then explicitly set it in foobar)
The files are 16bit 44100Hz.
Am I suppose to resample them?
Also, I am suppose to be able to use USB + up sampling right?
I am thinking the problem may have been some weird software thing though.
EDIT: false alarm, it's back. damn.
The files are 16bit 44100Hz.
Am I suppose to resample them?
Also, I am suppose to be able to use USB + up sampling right?
I am thinking the problem may have been some weird software thing though.
EDIT: false alarm, it's back. damn.
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Not sure it helps, I experience similar with any kind of inputs.
The severity varied with different opamps. I was about to give up and decided to check one simple thing - the voltage into the opamps. If memory served me right, the V- was at only -3V which was way too low. It is worth to give it a measurement to confirm.
Good luck.
The severity varied with different opamps. I was about to give up and decided to check one simple thing - the voltage into the opamps. If memory served me right, the V- was at only -3V which was way too low. It is worth to give it a measurement to confirm.
Good luck.
checked the voltages, they seem fine. 11V or so.
Thanks anyway pchw.
EDIT: looked at it again.
now that I look at again, I am getting 11.75V on V- and 10.75 on V+
This seems like quite a great difference, but I don't think that cause any of these problems.
Might be why I've been thinking that the balancing seemed off a bit..
=/
Wasn't expecting this thing to be such a hassle.
Thanks anyway pchw.
EDIT: looked at it again.
now that I look at again, I am getting 11.75V on V- and 10.75 on V+
This seems like quite a great difference, but I don't think that cause any of these problems.
Might be why I've been thinking that the balancing seemed off a bit..
=/
Wasn't expecting this thing to be such a hassle.
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The readings look within the specs. In my case, it was like +11 and -3!!
You can adjust the voltage by turning the pots in the power supply. These are multi-turns, so the change won't jump. This is not likely the cause of the pop, but it still bugs if you know something is far from perfect.
Good luck!!
You can adjust the voltage by turning the pots in the power supply. These are multi-turns, so the change won't jump. This is not likely the cause of the pop, but it still bugs if you know something is far from perfect.
Good luck!!
so, I decided to check the voltages of the DAC while I was at it.
VD, Digital Power - 3.33 - NORMAL
VA, Analog Power - 5.1 or so - NORMAL
VREF, Voltage Referance - 10.15V !!!!
Is that normal? The Datasheet for the DAC says it should be in the 5V range.
EDIT: so there is no way thats right, looking at the schematic.
I am thinking maybe my transformer is output 10V and that the regulator in charge of that is doing nothing at all.
how do I figure out which regulator it is?
Is it time to send it back?
VD, Digital Power - 3.33 - NORMAL
VA, Analog Power - 5.1 or so - NORMAL
VREF, Voltage Referance - 10.15V !!!!
Is that normal? The Datasheet for the DAC says it should be in the 5V range.
EDIT: so there is no way thats right, looking at the schematic.
I am thinking maybe my transformer is output 10V and that the regulator in charge of that is doing nothing at all.
how do I figure out which regulator it is?
Is it time to send it back?
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