Or I'm too fk'd up from lack of sleep. I am using ancient NAIM NAP 250s. I could swear they have only ONE XLR-3 input on the back of each.
Looking around it does look like Naim used a single XLR for unbalanced L/R/G. I guess this gives you the option of bridging it by plugging in a normal, balanced, signal.
For your setup, unless you want to bridge them, you'll need to make some custom cables. From the DCX, you'll want to use pin 1 for ground and pin 2 for phase+ signal. Pin 3 you can either leave open or connect to pin 1 for extra gain on pin 2.
On the Naim end, I have no idea. At a guess, I'd first try pin 1 for ground and then see whether 2 is left or right. A bit of trial and error and you should be able to figure it out.
For your setup, unless you want to bridge them, you'll need to make some custom cables. From the DCX, you'll want to use pin 1 for ground and pin 2 for phase+ signal. Pin 3 you can either leave open or connect to pin 1 for extra gain on pin 2.
On the Naim end, I have no idea. At a guess, I'd first try pin 1 for ground and then see whether 2 is left or right. A bit of trial and error and you should be able to figure it out.
Hmmm thanks. What considerations would I give to deciding on the extra gain being desireable or not?
Thx again. Do you know if Jan's active mods reduce the gain at all (yes I know it is then attenuated, but the not sure what his mods do before that.)
Also question, I'm sure cost wise this unit must have only one AK DAC and this is a 2 channel, how do they get 6 channels out is it basically muxd?
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From my recollection of owning 3 briefly (triamped Briks), the XLR was for a preamp power supply out.
I just dropped two I/O boards and two digital boards to local radio-tv repairer who changes the DACs and op-amps to them. We agreed the cost limit to be 100 euros, could cost even less.
Yesterday I changed PSU's capasitors to low-ESR Nichicon caps designed to be used with switching power supply. In theory it could benefit transient/bass response slightly. I could not compare the two DCX's since the other is not burnt in yet. I did notice some difference between their sounds in a/b comparison (slightly more bass, fuller sound) but coudn't tell was it because of the new caps or the lack of burn in. Also the RMAA result vere slightly better, but this was so slight that it could be due the natural variation.
After verifying that my mod worked I changed some caps on the digital board. Those five caps that are nearest to the ADCs I changed to Elna Cerafines, and from the capasitor herd near the PSU I changed all 10µf caps except the three that are between the power regulators. RMAA measurements showed that THD% and IMD% dropped:
THD%
before: 0,0094 %
after: 0,0044 %
IMD%+noise
before: 0,014 %
after: 0,0080 %
IMD% over freq:
before: 0,056 %
after: 0,045 %
In graphs, these lower THD and IMD values show themselves as less "noise" in the high frequencies. IO have attached a picture of THD graph comparison.
I have not yet changed the caps in the I/O board nor the caps that are next to the DACs (will do once I collects the boards).
After I have collected the boards with new op amps and DACs I will run some test to verify the possible improvement. I'm pretty excited to hear the AK4396's sound, it has got good reviews and seems to live up to it's name "crystal".
After this I will change the rest of the capasitors and measure and listen again. Then I'm finally done with this "improvements based on the stock design" modding. If neither of the DCXs doesn't die in the process I'm kind of a surprised.
It seems that replacing the stock capasitors to some high quality caps is a very easy and quite benefial upgrade to DCX. Take a look, this result even with half of the stock caps still inside:
Yesterday I changed PSU's capasitors to low-ESR Nichicon caps designed to be used with switching power supply. In theory it could benefit transient/bass response slightly. I could not compare the two DCX's since the other is not burnt in yet. I did notice some difference between their sounds in a/b comparison (slightly more bass, fuller sound) but coudn't tell was it because of the new caps or the lack of burn in. Also the RMAA result vere slightly better, but this was so slight that it could be due the natural variation.
After verifying that my mod worked I changed some caps on the digital board. Those five caps that are nearest to the ADCs I changed to Elna Cerafines, and from the capasitor herd near the PSU I changed all 10µf caps except the three that are between the power regulators. RMAA measurements showed that THD% and IMD% dropped:
THD%
before: 0,0094 %
after: 0,0044 %
IMD%+noise
before: 0,014 %
after: 0,0080 %
IMD% over freq:
before: 0,056 %
after: 0,045 %
In graphs, these lower THD and IMD values show themselves as less "noise" in the high frequencies. IO have attached a picture of THD graph comparison.
I have not yet changed the caps in the I/O board nor the caps that are next to the DACs (will do once I collects the boards).
After I have collected the boards with new op amps and DACs I will run some test to verify the possible improvement. I'm pretty excited to hear the AK4396's sound, it has got good reviews and seems to live up to it's name "crystal".
After this I will change the rest of the capasitors and measure and listen again. Then I'm finally done with this "improvements based on the stock design" modding. If neither of the DCXs doesn't die in the process I'm kind of a surprised.
It seems that replacing the stock capasitors to some high quality caps is a very easy and quite benefial upgrade to DCX. Take a look, this result even with half of the stock caps still inside:
Attachments
I did just basic RMAA. It has pre-set IMD% test, which measures the IMD with two tones, one at 60 Hz and one at 7 000 Hz. Is there some more versatile measurement tool? Preferably one that is free or available in "the other way".
The pure stock unit was broke in for 2 weeks maybe before that measurement, the modded unit's new parts were broke in maybe for 30 minutes
.It would be good test that I measure my newly modded units straight after modding and then measure them again after 2 weeks of daily use. I personally don't think the actual measurements will change, even though the tone quality might change little during the break in.
Me neither - but your measurements and panomaniac's multi tone measurements made me think about "eventually re-think" that standpoint.
Michael
Me neither - but your measurements and panomaniac's multi tone measurements made me think about "eventually re-think" that standpoint.
Michael
How did my measurements made you thinking about re-thinking?
When I will measure again my modded DCX's in two to three weeks, do you think they will measure better, same or worse compared to the initial measure which will be done approx. 30 minutes after the mods have been installed? It shall be very interesting if there should be any differences that can't be explained with natural variance.