Constantine USB DAC Rant - Page 3

Thanks, Justin, for clarification.
I hope the next version will have it all, including line out.

alright guys, enough talking about microdac or stello and back to the topic of usb vs optical/coax-in on the mhdt lab dacs. well, i don't have the constantine, but i was able to compare the usb-in with the optical-in on my paradisea+ for a couple hours today. i believe the paradisea+ uses the same usb chip from c-media as the constantine. to me whatever difference between the two inputs was very very small. i think i hear a little more treble sparkle and high-frequency details with the optical-in, on the other hand, the midrange of the usb-in seems slightly fuller sounding. it really required some careful listening to be able to pick out the differences. if i was blindfolded, i highly doubt that i would be able to pick out which one was which. forgot to mention, my source was itune playing apple lossless files through my computer's usb port and built-in optical port (realtek). anyway, i definitely didn't find the drastic difference the original poster found in his constantine. going into the comparison, i was totally expecting to hear a much worse sound from the usb-in, but that was not the case. on a side note, the improvement i heard when i upgraded the power cord and when i put in the bendix 6385 tube were significant greater. just want to share my finding...

you are right, constantine and paradisea are different beasts. but my understanding is that the implementation of the usb input should be similar on both, using the c-media chipset.

btw, i've also tried the asio4all driver, though i don't really think that it sounded significant better than itune, it definitely didn't have any noticeable static. this makes me think that something might not be quite right with your setup. you might wanna try it with another computer. have you tried asio4all with other dacs, or just the constantine? you might want to do a little investigation here. although whether asio4all driver actually improves the sound quality is debatable, it definitely should not introduce any static to the sound...

finally, you caught me, i'm not really a head-fi person, so i don't currently own any high-end headphones or headphone amps. i've tried my paradisea+ with both my NAD amp and my Simaudio amp. Regarding power cord, I've only tried Zu Birth and Audioquest Noisebuster. I'm sure there are much better and more expensive power cords out there. the point I've been trying to make is that if you are using a generic computer style power cord (like i was before), then you might want to consider upgrading. but how much you should spend on the power cord is obviously up to your budget and taste. for me, the $40 i paid for the Zu Birth was probably how much i would want to pay, and it made a significant improvement. i'm sure i could spend $1000 for a Tara Lab and get even more improvement, but i'm not willing to spend that kind of money on a power cord.

The older Constantine is a different beast but the newer version is, in fact, quite similar to the Paradisea - minus the tube buffer. Maybe it has something to do with the voltage.

"As for the Costantine, indeed it is P+ without tube buffer basiclly.
All capacitors are in same grade (Nichicon KZ) but lower voltage.
OP is LM4562 same as P+ but working in lower voltage (+-9V), P+ is about 13+-.
OSCON cap is 100u while P+ is 470u.
P+ has many caps used because the tube stage.
Others are the same..

Thanks!!

Best Regards,
Lin-Li
Mhdt Labs"

USG,

Can you explain what "over-samply" means? I've not done very critical listening of a NOS DAC.

Thanks.

Not quite accurate - Mhdt didn't originally assume USB would be good for DAC input, but decided to try it anyway after many customer requests. After careful design and much test, Mhdt does feel their USB implementation is a success - but recommends using ASIO4ALL to achieve best sound quality with this interface. If Mhdt didn't think USB was appropriate, they wouldn't have implemented it in their DACs. [This info comes from direct communication with Mhdt.]

there's no reason why asio4all shouldn't work with your usb connection. you should:
1. make sure it's set up and configured correctly
2. make sure it's compatible with the OS you are running, and there's no conflict with other devices you are running
3. if all else failed, contact mhdt lab directly to see if you might have received a defective unit with a bad usb connection.

nah, what you were describing has nothing to do with resolution. plus even if my speaker + amp setup might not be in the ultra expensive exotic range, they probably still cost a few times more than the average headphone setup most people have on this forum. not to mention that i did own most of the headphones in Sennheiser's line-up at one point a few years back...

anyway, the problem you were having has nothing to do with whether usb is better than optical or vice versa on the constantine. sure the optical might still be better than the usb connection. but even if that's the case, the usb should still be far from unlistenable, and definitely should not demonstrate any static as you described even when used with asio4all. so if you are hearing any static noise on your constantine through the usb connection, then something is not right. you should really check with Mhdt Lab for a fix. but what the heck, it's your DAC, if you don't think it's worth investigating and can live with the optical input only. i guess it's really none of my business...