Audio-gd Digital Interface
May 24, 2011 at 4:58 PM Post #2,027 of 4,156


Quote:
I'm not sure if this has been discussed within the thread, but has anyone tried the no-change setting without the clock in the socket?
 
I was testing between the stock clock, a Vanguard TCXO and a Tentlabs XO for the upsampling. In the end I preferred without upsampling. Since Kingwa said the clock is not used in the no change setting, I took out the clock. Surprisingly there seems to be some difference in the sonic and I wonder if there's any influence the clock has in the socket and without. I tested all three clock in the socket in the no-change setting. There were perceptible changes in the sound with each clock having a subtle impact on the sound. In the end, I found that no clock in the socket turns out to provide the most transparent and clean output signal to the DAC. Details and ambient information are a lot more noticeable without any clock in the socket. I thought Kingwa said the clock isn't used when not upsampling but it seems to have an effect on the signal.


Same result here. I already using DI without upsampling but when I took out clock sound get more transparent and hard passages (eg many instruments playing different partitions at same time) get more clear. I am using it with nfb10es btw.
 
 
May 24, 2011 at 7:54 PM Post #2,028 of 4,156


Quote:
It's curious that we don't have a consensus on the effects of upsampling.

Indeed, very curious. I tried non-upsampling mode this afternoon and liked it, just not as much in Classical scores. I feel that the instrumental separation and soundstage in complex symphonic music is better with up-sampling. On vocals (Patricia Barber, k.d. lang) with small instrumental groups, the sound is extremely truthful and non-fatiguing. I frankly can't tell the difference between “up and non-up” on Rock band tracks like, for instance, Angra's various albums or Pink Floyd's DSOTM and Division Bell. The Dead Can Dance discography, however, sounds sensational with up-sampling. Well, this last group has always been extremely well recorded so maybe it really doesn't matter what setting on the DI you might choose.
 
 
 
May 24, 2011 at 10:19 PM Post #2,029 of 4,156


Quote:
Hey rhythmic, just to confirm a few things:
1) how long have your Vanguard TCXO been burned in?
2) have you controlled for the listening volume?
 
Vanguard TCXO and the one Audio-gd is selling look the same in its physique and form factor (except its engraving). Anyone can confirmed that they are the same chip?
 
With the TCXO clock and without upsampling, I find the vocals to be more upfront and I could listen comfortably at low listening level to what the singers are singing.
With the TCXO clock and with upsampling, I find the vocals to fall back to the other instruments: I will need to play on a higher volume now as before in order to hear the vocals clearly. This in return makes me listen to other instruments more loudly as well.


uelover,
 
The TCXO and the Tentlabs were each burnt-in over a 3 weeks period each. This was something I had been testing for the past 2 months before posting the results here. Yes, the volume on my DACs remain the same. I sent an email to Kingwa asking about this and whether the circuits are affected by the insertion of the clock but he gave me a very generic reply saying that clock will only be used when in upsampling mode.
 
 
May 25, 2011 at 2:27 AM Post #2,030 of 4,156
i'm going to receive the Audio-gd PSU for DI next week and i'll also definitely buy an USB isolator dongle because i really hear how my PC pollutes the sound.
a guy named "Leeperry" had massive experiments with those, so, following his impressions, i guess i'll buy this one: http://www.olimex.com/dev/usb-iso.html
 
May 25, 2011 at 7:44 AM Post #2,032 of 4,156
it's one of them. yes. there i a variety of adum4160 realizations and as i've read - the Olimex one is the most interesting of those.
 
May 25, 2011 at 7:53 AM Post #2,033 of 4,156
Simple question (can't seem to find the answer on the AUDIO-GD site) - if we are inputting a 16/44.1 signal to the DI, and using the 96kHz upsampling, is it also converting the 16 bits to 24 bits?
 
Reason I ask is that I am using a non-oversampling AD1865, so I am trying to work out what signal it can accept.  I think the 96kHz is okay, but I am not sure about 24 bits as it is an 18 bit DAC chip.
 
May 25, 2011 at 8:34 AM Post #2,034 of 4,156
ad1865 should understand 24bits.
i have a DAC on ad1862 and it does.
 
May 27, 2011 at 1:52 AM Post #2,035 of 4,156
Just installed a 74VHC04N in my DI. Huge upgrade (and I haven't even burnt it in yet) for such a small investment, mainly in terms of bringing out detail. My music sounds almost like it's in slow motion the way that the details are being fully conveyed now. Can't wait to get a few more hours on it.
 
May 27, 2011 at 2:35 AM Post #2,036 of 4,156
Nice to hear that.
 
I have difficulty sourcing for one on my side. Mouser charges USD30 for shipping and a few cents for 74VHC04N which is a little too ridiculous.
 
eBay doesn't sell the VHC variant but sells the HC variant.
 
 
What are the difference?
 
May 27, 2011 at 3:27 AM Post #2,039 of 4,156
Nice to hear that.
 
I have difficulty sourcing for one on my side. Mouser charges USD30 for shipping and a few cents for 74VHC04N which is a little too ridiculous.
 
eBay doesn't sell the VHC variant but sells the HC variant.
 
 
What are the difference?


The HC is the same as what's in there by default. VHC is what borrego recommended. I have 3 of these VHC left and I could ship you one if you paid me $2+airmail. Shoot me a PM if you're interested.

what do you mean by "slow motion"?


The music almost seems slowed down because of the amount of detail being resolved. Instead of notes playing into eachother they're more separated and discretely positioned than before. Soundstage also seems improved.
 
May 27, 2011 at 10:42 AM Post #2,040 of 4,156
reporting:
i've bought an Audio-gd PSU for DI from a nice guy here if FS forum, received it an hour ago.
that's a nice upgrade, i should say.
imho, not worth $120 (as it would cost me to be shipped from Kingwa), but for the $72 shipped that i've payed, it is pretty good.
feeding DI with a usual D-link 7.5v/1A PSU (taken from my internet-router) sounded nicer than usb-powered. feeding it from audio-gd's PSU gives twice better improvement comparing to a that PSU.
 

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