Lossy music and resolution.

[namaiki]

I've read:

1) DAC's are 24bit at best...drivers will either ignore the 8 bottom bits, or worse convert from 32 to 24.

2) no point in doing useless conversions, Reclock will either do the same or better conversion to 32float than ffdshow would...just make sure to decode lossy audio to 32float whenever possible, in order to avoid rounding errors and useless conversions.

You should input in reclock the format that will need less prior conversions. For example:
(1) a 24 bit lossless soundtrack should be sent to reclock as PCM 24, If you convert it to 32 bit floating point and input that in reclock, it would not be lossless anymore, because ffdshow's conversion to 32 bit floating point is not as accurate as reclock's conversion, even though you would not be able to hear the difference.
(2) a lossy encoded soundtrack decoded using 32 bit floating point, should be sent to reclock as floating point. ffdshow's conversions from floating point to PCM are not as accurate as reclock's

*ALWAYS* decode lossy audio to 32float whenever possible(read above for the reason )

Perhaps I'm reading out of context, but say I am playing an MP3 file(ReClock audio-only mode) -> wasapi-> headphone jack out-> headphones
Sampling rate: 44.1 KHz
Resolution: 16 bits

..should I be setting FFDShow Audio to output in 32-bit float and ReClock in 24-bit int padded? Or more like just both at 16-bit?

 

[leeperry]

should I be setting FFDShow Audio to output in 32-bit float and ReClock in 24-bit int padded?

yup, 24 or 32bit...depending on how your drivers cooperate(24 can be problematic IME, padded or not).

 

[namaiki]

I advised this one to a friend, and it made him sell his STX: http://www.audiophonics.fr/info-ng27-amplificateur-casque-usb-ipod-dac-pcm2702-p-5006.html

USD90 shipped on ebay from a chinese seller, put some nice op-amps(LT1364CN8 as final buffer for instance), use KS/WASAPI(it supports both w/ the ploytec USB drivers) and you're good to go! 16/48 max, though

it's a fake Neutrik plug btw, but well

Okay, I just made this thread, so I don't think I should make another one.

Just a question about this 'replace the something with the LT1364.' I had a look on the HA INFO NG27 page and the bottom picture is of the internals of the DAC.

It looks like there are two replaceable chips, so would I be needing two LT1364s for that?

 

[leeperry]

Just a question about this 'replace the something with the LT1364.' I had a look on the HA INFO NG27 page and the bottom picture is of the internals of the DAC.

It looks like there are two replaceable chips, so would I be needing two LT1364s for that?

there's 3 of them:
-two single op-amps(BUF634) to drive your headphones
-one dual op-amp(OPA2604?) as final buffer on the DAC output

replacing the BUF634 would take some time, as you'd need an op-amp w/ high current output(to properly drive the headphones)...but replacing the lofi OPA2604 by a LT1364CN8 will send you up in the sky

this amp comes w/ a LT1364 stock: http://www.audiophonics.fr/poppulse-dac-707-convertisseur-audio-numerique-24bit192khz-p-4379.html

this is a much better sounding chip than the LM4562/LME497xx/LME498xx....you can get better, but not by a night and day...the LT1364 is a very good chip(or better two LT1363 on an adapter to get a clearer stereo image )

 

[namaiki]

Messaged a couple of eBay sellers: http://shop.ebay.com.au/i.html?LH_AvailTo=15&_nkw=DAC+707

Not sure if it is the same product though.. :doh:

 

[leeperry]

this is a DAC, not a DAC+headamp

 

[namaiki]

edit: messaged two eBay sellers and probably confusing the heck out of them and me.

I think I'll have a look at the HA INFO NG27 again.

With the OPA2134(as it appears to have stock) instead of the LT1364, do you think I could expect it to sound warmer, or would it just sound crappier/sloppy?

 

[leeperry]

With the OPA2134(as it appears to have stock) instead of the LT1364, do you think I could expect it to sound warmer, or would it just sound crappier/sloppy?

less detailed, less impressive, less "taking the headphones off your head"...rather boring.

OPA2134 is the lesser grade of the OPA2132

very often the 1364 will give you the feeling to be in the studio cabin right next to the singer, that's how good it is!

as a friend of mine would say:

LT1363/4/5
Great for buffers, not so hot for something with high gain like I/V or amplification. Sometimes, but only sometimes, you feel like you're in the studio or concert hall... Can be a bit bright and anemic if it isn't supplied well.

 

[leeperry]

some food for thoughts: http://www.head-fi.org/forums/6334309-post5.html

 

[namaiki]

Thanks for the warning. ;_;

 

[namaiki]

Okay, I am set (in my head ). I am going to purchase the NG27, and then chuck in a LT1364. (a start at the very least)

The thing is the NG27 will come with either a OPA2134 or OPA2604, so which of those two do you think would perform better?

edit: it appears that OPA2134 is the safe option and OPA2604 can sound really bad, or slightly better than OPA2134 if it has enough voltage.

 

[leeperry]

OPA parts are no match to the LT...2132 is bad, 2134 is worse and 2604 is worthless. LT1364 crushes them all :agree:

 

[leeperry]

I'm currently listening to four LT1363 on the Prodigy HD2 DAC output...it gives better stereo seperation than two LT1364, dual op-amps carry a way too high crosstalk to my taste(many ppl agree on this, even Browndog that sells adapters for them).

it's got the major advantage of being "unity gain stable", meaning it'll work pretty much anywhere..I loooved the AD797B/LT1028A combo but neither of them is! and they were giving random pops, I hate murphy's law

you can read some tests from a notorious opamp'holic here: http://www.head-fi.org/forums/f6/au...ewed-OPA-earth-OPA-moon-OPA-sun-v-2-a-397691/

I'll try AD8597, it seems very promising! 8)

 

[leeperry]

hehe, cool I'm exchanging PM's on diyaudio.com w/ the AD797 designer...I love the internet

anyway yeah, when I listen to a 1363/1364, I don't see a cartoon anymore...I picture the dubbing actors recording in the studio cabin, talk about analytical sound ^^

and the soundstage on this chip is very impressive too.

 

[namaiki]

Waiting for (another) reply from (another) eBay seller..

 

[leeperry]

they should make an OA(Op-Amp'holics Anonymous), it's a nasty disease! I dearly hope that you won't fall into it...it's worse than a drug, just say "no thanks" ^^



I'm currently listening to LT1113ACN8, and I love it...hah

 

[leeperry]

I still think that LT1363 does just about everything a man could need, it's got a VERY fast slew rate that allows it to capture far more low level details than most other chips.

but eventually, enough is simply never enough to some ppl :disagree:

My ultimate DIY stereo soundcard - Head-Fi

 

[namaiki]

What do you think about these? (I was waiting for a reply from ebay seller about ng27 but the auction ended and I haven't written again >_>)

NG98 #1
NG98 #2
(btw, I live in Australia )

Differences:

CS4398 vs AD1852 (leaning towards the AD1852)

and #2 mentions "I/V and LVP: Burr-Brown OPA2604*3" which I have no idea what that means(perhaps #1 is the same in regards to this parts?).

 

[leeperry]

yeah I saw those two, they have even more replaceable op-amps: http://www.audiophonics.fr/info-ng98-headphone-amplifier-dac-usb-spdif-ad1852-p-5008.html

I can't comment on the two optional DAC cards w/o hearing them...you need to look up their datasheets and see how high they do oversampling(AK4396 does 128X up to 192kHz), but op-amps are known to color the sound far more than DAC's...I would personally not worry too much about it.

thing is, the NG27 for USD90 + one LT1364(or better two LT1363) was a no brainer...but the NG98 for USD150 is another story altogether, there's a tough competion in that price range...OTOH it supports 16/96, which would be really nice for using Reclock w/ movies :agree:

 

[namaiki]

the NG98 for USD150 is another story altogether, there's a tough competion in that price range

Anything quite outstanding? I don't mind paying a bit more.

Though I am this close to purchasing the NG27 + LT1364.

btw, do any of these seem fine?

cheapest?

2

3

most costly

Some of the LT1364CN8 are sold in pairs is what confuses me..