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dac & amp question

post #1 of 14
9/3/10 at 8:16am
Thread Starter 

Hi all


I'm new to this forum.
I'd like to buy a dac with the matching amp and need your help before i make up my mind.

Most of the songs i have are lossless with some in 24bit, 96KHz and preserving this quality from the source over

to my Sennheiser HD 650 is of importance.

 

Currently the source is ipod and laptop.
My 80gig ipod classic does not play 24/96 songs. Even if i copy 24/96 songs onto it the songs are downsampled to
16/44 or 16/48 depending on what they are. My laptop is ok to play 24/96 songs.

As for the DAC and amp my plan is to buy a LD DAC I with a LD MK III tube amp or MK V solid state amp.
I like both the tube and ss amps, however i don't have much experience with tube amps.
 
 
Within the many posts about LD DAC I i found the following:

"I wonder how after 10 pages nobody noticed this but... It must be said this DAC when fed data by USB will go to 16bit/48kHz max, as it does use the ubiquous BB PCM2704 chip for USB input.
So for anybody looking to use for computer audio with HD downloads, this is an important thing to look for. I must say neither DacMagic and V-DAC are able to do HD audio from USB for the same exact reason.
I wanted to clarify because someone asked about this, and there is no mention of it on any of the tech data (I find a bit misleading btw).
Regards
Josep"

From the above it seems the LD DAC I is not capable of playing 24/96 songs if the source is connected via USB.
It is also mentioned in the LD DAC I specifications on LD's website: "USB input: 16-bit / 48 KHz"
What if i use coax or optical cable to connect the source to LD DAC I ? Is that feasible to transport 24/96 to the LD DAC I ?
I do not want my songs to be downsampled.

Is there any DAC that handles 24/96 via USB ?


I do not know much about tube amps. If i chose the MKIII tube amp, what should i know about its maintenance?
How frequently do i need to change the tubes? What indicates that if a tube needs to be changed?
When they need to be changed, do i need to change the entire set of tubes?


Can you tell me what type/brand of cable i should buy to wire the above properly?
 

 

 

Thanks, David.

 

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post #2 of 14
9/3/10 at 4:51pm

If by "handles 24/96 via USB" you mean it has an upsampling chip integrated in the circuit after the USB receiver, there's the Audio GD's. The UDAC2 says it's 24/96 so I suppose it does that, too, given no USB chip can send out and receive 24/96. As for tube maintenance, generally the MkIII is still easier to service given the tubes are socketed, and outside the chassis, unlike other designs where they're soldered into the board and inside the chassis.


Edited by ProtegeManiac - 9/3/10 at 4:54pm
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post #3 of 14
9/3/10 at 6:00pm
Thread Starter 

"given no USB chip can send out and receive 24/96" - so as i understand 24/96 via USB isn't possible without upsampling.
 If i use coaxial or optical cable to connect my laptop to LD DAC I, would that transport the the 24/96 songs to the DAC without downsampling them?

Can you also help me out with an answer to the other 3 questions

How frequently do i need to change the tubes?
What indicates that if a tube needs to be changed?
When they need to be changed, do i need to change the entire set of tubes or is it ok to change only one of them,
say ... if only one goes wrong? or it is not advisable to change only one of them.
 

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post #4 of 14
9/3/10 at 7:59pm

1. Only when the filament in the tube burns out that's when you need to change the tube. Tubes last a long time.

2. There is really no way to check unless you have a vacuum tube tester.

3. No, you can just change the bad one.

 

Some vacuum tube amps have an auto-bias circuit. Some have manual bias. But you need to know the bias voltage.

 

Quote:
Originally Posted by Dohara View Post

"given no USB chip can send out and receive 24/96" - so as i understand 24/96 via USB isn't possible without upsampling.
 If i use coaxial or optical cable to connect my laptop to LD DAC I, would that transport the the 24/96 songs to the DAC without downsampling them?

Can you also help me out with an answer to the other 3 questions

How frequently do i need to change the tubes?
What indicates that if a tube needs to be changed?
When they need to be changed, do i need to change the entire set of tubes or is it ok to change only one of them,
say ... if only one goes wrong? or it is not advisable to change only one of them.
 

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post #5 of 14
9/4/10 at 3:46am
Thread Starter 

Thanks ProtegeManiac and wuwhere

 

 

 

If i use coaxial or optical cable to connect my laptop to LD DAC I, would that transport the 24/96 songs to the DAC without downsampling them?

what type/brand of cable i should buy to wire the above properly?
 

 

 

David.

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post #6 of 14
9/4/10 at 8:30am

Unless your laptop has a dedicated SPDIF (coax or optical) output there is no way you can transmit the 24/96 natively. What will happen is, a USB to coax converter will receive it as 16/44 from the laptop, then send them over to the LD DAC. Some USB to coax interface can upsample the signal back though. Some have toslink output via theheadphone out, you jsut need a special adapter, but I'm not sure if that's capable of doing 24/96.

 

Other ways to transmit 24/96:

 

1) Buy a desktop with a good soundcard that can output 24/96. I'm using my onboard sound card because it has SPDIF and the last time I installed a video card it wouldn't run on my HP, so I said, what the heck, I'll not risk hasslign myself. And most likely I might jsut assemble my next PC from scratch so no conflicts with bundled drivers on recovery discs, as I'm not software savvy.

 

2) Buy an NMT with an internal HDD, upload your 24/96 files, and play it from there. Just make sure it can output at that resolution through SPDIF.

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post #7 of 14
9/6/10 at 6:18am
Thread Starter 

 

I have an external sound card that is connected to my laptop through USB.
It is a TASCAM US-144mkII, with S/PDIF stereo coaxial input and output.

If i connect the TASCAM to the LD DAC_I via coax would that be a solution to play 24/96 ? no matter if the
TASCAM is connected to the laptop via USB ?
 

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post #8 of 14
9/6/10 at 7:56am

I haven't tried that unit but as long as it does the upconversion then it should be fine. Take note though it's still not the same as sending it out natively from a PC with a good internal soundcard. What will happen is, your laptop will downconvert to 16/44, then send it via the USB, at which point hte Tascam box will upconvert to 24/96. For the really, really OC audiophiles, that's too much digital processing. But I say try it anyway, if it turns out great and you like the sound, then that's that.

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post #9 of 14
9/8/10 at 7:30am
Thread Starter 

Hi

 

Thanks for all of your help, i really appreciate it

 

cheers, David

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post #10 of 14
9/10/10 at 5:35am
Thread Starter 

Hi

 

 

If i used an external sound card that is connected to laptop via firewire, would that make any difference ?

Or the 24/96 songs would still be downsampled to 44,1  then upsampled by the sound card ?

 

 

David

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post #11 of 14
9/10/10 at 5:47am

I don't know if Firewire supports 24/96, but AFAIK, it'll be the same. 16/44 to soundcard upsampling it to 24/96 to DAC.

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post #12 of 14
9/10/10 at 6:30am

Couple of thoughts: There are now a few USB receivers that can handle 24/96.  Firewire can handle anything.  I seriously wouldn't bother caring about 24/96 with cheap gear.  If you're spending thousands on hi-fi, maybe, but with a $300 or however much DAC? If there is a difference (which is debatable) then you're not going to notice it. 

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post #13 of 14
9/10/10 at 11:31pm
Thread Starter 

Hi


thanks for your reply


Which usb dac do you think would make a noticeable difference between 16/44 and 24/96 songs and receive 24/96 songs without up/down sampling?
The reason i decided to try Little Dot is that i currently have no space/room for a hi-fi system (in the middle of house hunting)
but i want to listen to good quality music until i get there. So i thought a proper source,dac,headphone amp and a good headphone would do that and i have read lots of good reviews about Little Dot.


On a longer term i plan to build my hi-fi system and i don't mind spending more money on the dac right now.


For my future hi-fi setup I have a pair of Canton Chrono 507 DC speakers but I still need to find an amp to drive them.
So it would look like:
Laptop - Dac - amp - Canton Chrono 507 DC


http://www.canton.de/en/hifi/chrono/produkt/chrono507dc.htm


Which DAC would you suggest?
If you have experience with Canton, would you also tell me which amp i could try with Canton speakers?
 

 

 

thanks, David

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post #14 of 14
9/17/10 at 3:20am
Thread Starter 

Hi all

Can you please suggest me a high quality usb DAC that handles 24/96 song files and can be used for both
Little Dot III tube amp (and later to my hifi that includes Canton Chrono 507 DC speakers?)

Still don't know which amp matches best the Canton Chrono 507 DC so any advice is welcome. (further detail is above)

Thanks, David

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