My December-bought DCX stopped working after a month: upon switch-on, the display screen would lit but remained blank, and the LED segments on input channel A and output channel 1 were all lit - the unit was "frozen" like that.
The dealer replaced it with a new unit.
However this second unit behaves similarly after switch-on: sometimes the display is lit but without any data on it, and no LED segments lit/ sometimes the display (w/o any data) and the LED segments are all lit....... However this time - for now at least - the next switch-on will bring it back to normal.
Any similar experiences? What may be the culprit? I am about to implement the mods (Oettle src/clock and direct outs) but would like to solve this first.
The dealer replaced it with a new unit.
However this second unit behaves similarly after switch-on: sometimes the display is lit but without any data on it, and no LED segments lit/ sometimes the display (w/o any data) and the LED segments are all lit....... However this time - for now at least - the next switch-on will bring it back to normal.
Any similar experiences? What may be the culprit? I am about to implement the mods (Oettle src/clock and direct outs) but would like to solve this first.
I was wondering if anyone had replaced the ADC's for ASRC's to accept I2S in various flavours, and does it make sens to do so or is optical just as good.
Connecting I2S directly to the DSP would require major surgery, and it would only be able to handle 96khz 24bits.
Does anyone know why one of the ADC's of the DCX inputs (left and right) are tied together? I know it is a mono configuration but why tied them? doesn't make sens to me
Connecting I2S directly to the DSP would require major surgery, and it would only be able to handle 96khz 24bits.
Does anyone know why one of the ADC's of the DCX inputs (left and right) are tied together? I know it is a mono configuration but why tied them? doesn't make sens to me
I was wondering if anyone had replaced the ADC's for ASRC's to accept I2S in various flavours, and does it make sens to do so or is optical just as good.
Connecting I2S directly to the DSP would require major surgery, and it would only be able to handle 96khz 24bits.
Does anyone know why one of the ADC's of the DCX inputs (left and right) are tied together? I know it is a mono configuration but why tied them? doesn't make sens to me
I've never understood that either. This is the ADCs that receive the C-channel input. For one, the tying together doubles the already low load on the driving opamp. That can't be good for the distortion performance.
It may have to do with how they switch the ADC outputs around to the switch matrix and DSP. Tying together probably saves them a switching pin, but I haven't checked that in detail.
jan didden
Input C is intended for measurements and other auxiliary purposes only. It therefore has a cheaper ADC than the main inputs (AK5383 as opposed to an AK5393 for inputs A and B).
I always thought that feeding both input channels of that ADC saves the DSP precessing power and eases code development efforts for spreading the monaural digital stream across multiple signal paths during the auto-align process.
I would imagine that leaving one channel muted would create more work and new problems with a now funny digital signal during software development.
Or maybe a DAC like this behaves odd in the digital domain with one channel "empty"?
I always thought that feeding both input channels of that ADC saves the DSP precessing power and eases code development efforts for spreading the monaural digital stream across multiple signal paths during the auto-align process.
I would imagine that leaving one channel muted would create more work and new problems with a now funny digital signal during software development.
Or maybe a DAC like this behaves odd in the digital domain with one channel "empty"?
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I never knew that input C was for auxiliary purposes only.
But upgrading the DAC would make it a fully functional input, just like A & B or am i wrong ?
ps. I was thinking maby one of the channels is used for the measurments, it was maby developed in software like this and the hardware is later cut down to overcome costs.
But upgrading the DAC would make it a fully functional input, just like A & B or am i wrong ?
ps. I was thinking maby one of the channels is used for the measurments, it was maby developed in software like this and the hardware is later cut down to overcome costs.
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According to Asahi Kasei, the AK5383 is pin compatible to the AK5393, yes. The 5383 isn't that bad, though.
Simple as that, I guess. I assume the algorithms were developed first and the requirement for a stereo measurement signal somehow made it into the hardware specification.
No need for any magic to explain it.
My two cents.
Sebastian.
Balanced passive out modded DCX's THD, using digital input and balanced output, is nearly non-existent.
For quick comparison to the last weeks's measurements:
Unbalanced output, THD@-1dB = ~0,011%
Balanced output, THD@-1dB = ~0,0006%
Unbalanced output, THD@-10dB = ~0,004%
Balanced output, THD@-10dB = ~0,0003%
Also the IMD-measurements dropped at the same extent.
Here are the graphs (-4dB was taken with 24 steps per octave, others 6 steps pe
r octave)
For quick comparison to the last weeks's measurements:
Unbalanced output, THD@-1dB = ~0,011%
Balanced output, THD@-1dB = ~0,0006%
Unbalanced output, THD@-10dB = ~0,004%
Balanced output, THD@-10dB = ~0,0003%
Also the IMD-measurements dropped at the same extent.
Here are the graphs (-4dB was taken with 24 steps per octave, others 6 steps pe
r octave)
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.
An externally hosted image should be here but it was not working when we last tested it.
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Did you see these measurements? http://www.diyaudio.com/forums/digi...r-dcx2496-digital-x-over-296.html#post2462982
At least when used capacitors to block DC instead of transformers, the passive out modded DCX distorts mainly H2 with unbalanced output.
An externally hosted image should be here but it was not working when we last tested it.
Due to my 6ch volume controller (av-receiver) I have to use unbalanced outputs from DCX, so I get mainly H2 to the signal. Little flavor
. I should look into balanced 6ch volume controllers one of these days, because the THD is ultra low with balanced output and the max ouput voltage drom DCX would double.Ps. Unmodded DCX however had mostly H3 and H5 even when used unbalanced output. Here's my old plot of unmodded DCX with unbalanced outputs, taken approx. 6 months ago:
An externally hosted image should be here but it was not working when we last tested it.
Gents, I have a fairly new DCX2496 and all seemed fine until last night. It may have been the static shock I accidentally induced... (yes my bad but in my defense the house is at 20% humidity) So, now when I turn on the unit, the display lights up but stays blank and the Line A LED bank and Output 1 LED bank continuously pulses once every second. On rare occasions it will start up and boot as it is supposed to. But I fear something got damaged and not sure how to check/troubleshoot at this juncture.
Any ideas you may have are welcomed.
Any ideas you may have are welcomed.
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Thanks Legis, it conforms partly some other measurements I've seen that peg the xtalk at around -60dB. Doesn't seen a lot, although still much better than would be audible.
jan didden
I have a second DCX that behaves the same way as you describe. The first one (just about to be modified!) would not reboot at all, but was replaced by the dealer with this second new one.
Looks like it is happening often - the frozen display and LEDs. This really makes it difficult for those DIY-ers who modify - the mods void the warranty, and the mods could be costly too specially if the DCX freezes on you. Hmm?
In a way this is good. At least someone else has the same problem which means I will have to get in touch with the manufacturer. No mods for me. Not while on warranty anyway. Not surprised something as such would happen. Pay bottom dollar - get bottom quality...
The problem is that the DCX is basically a pro-audio positioned piece of equipment. Pro audio input and output levels are up to 14dB higher than home audio equipment. So if you mod your player, you have to keep on modding any other source you'll be using.
The output level is also too high so you'll have to turn it down more than ususal, and hopefully you don't overload your preamp/level control.
To use the DCX in an easy and flexible way in home hifi there's a lot to say for modding the DCX rather than the rest of your system.
jan didden