yeah I do see that. I don't know why it has an option for usb power in the menu. I thought I had seen differently from a previous pic. I suppose the iusbpower would be good then. no wonder coax sounds better.
Teac Reference Line UD-501 USB DAC "DSD" - Page 13
I also thought it has internal USB power supply when I bought it, many reviews copy&paste this mistake. In manual we see only:
USB input circuit power
The USB port is powered only when the input is USB. When any other input is active, the USB port is not powered.
The USB port is always powered.
It's not about switching from internal to external power supply. And who need to switch to external power when internal one is definitely much much better in any cases? I think it means only, you can switch off the power chip on the USB board when USB connected, but not selected as signal source, to avoid interference. So, Teac engineers thought it could be very noisy.
Edited by wztrack - 2/4/14 at 2:46pm
i just used my meter. it provides self power on the board. it does not use opto couplers but few dacs under 3 grand do. it is noiseless to my ears although i can scope noise. i can scope noise on pretty much any dac. it is a pretty good competitor(the usb implementation) for most dacs under 3 grand. the McIntosh,bryston,nad,mytek have similar noise floors on the usb. the benchmark dac2 is slightly better. of course these are measurements not my ears. anyways the output measurements are awesome for the price of this thing. the jitter on all inputs does not raise any eyebrows. plus i just happen to like the way it sounds. having the power on instead of auto does increase noise on spdif but not as much as you are thinking.the iusbpower may indeed improve what is already pretty decent. however with the Gemini cable you are buying a $400 usb buffer for a dac you can get for about $800. at that point i would go to a better dac. the thing is to seriously best the usb implementation on this you need to look at 5+x the price. they did something right. i wish i had the service manual. don't forget this is the company that makes esoteric. they wouldn't just go out and embarrass themselves there is a guy that has 3 pages of measurements online.that concure with mine. i did not know if he would want me to link him here. if you want google "archimago's musings". it is a three part series.he also has some information as to why he feels the usb implementation actually does not matter. in fact i measure all these dacs usb about the same as well. you may not agree about his feelings on cables but the measurements are facts. even though he did not have the best measurement equipment.
well i just got around to trying the headphone amp. it is pretty good(used hd800,k702). however i feel first and foremost it is a dac. headphone amps over $500 seem like they are mostly going to be better. over a grand and a lot better. benchmarks hpa-2 is better as well. a lot of people do not like that though. overall i think they could sell this box for $1,500 and get away with it fine.
Edited by music_man - 2/4/14 at 5:41pm
Sure, Teac engineers are very professional and they develop Esoteric series, but don't forget, they develop a lot of mp3-Iphone-all-in-one sound devices also ;)
I didn't tell it sounds bad. I just mention that it has no internal power supply for USB, it's is not isolated and they use low-cost power chip on the board. It's less about SQ, it's more about idea of reference device design. Dual power supply for dedicated mono chanells is about reference design, non-isolated USB powered board with impulse power chip is not about reference design, they save up here.
SQ is good generally, but It would more depend form computer sources, cables etc here. And same device with isolated USB part powered on linear internal power supply will sound better in most cases.
It's sad that Teac engineers mix esoteric and all-in-one boom-box device design here.
It's on my would like to buy list. Not that I'd be using the built in headphone amp (except maybe to get a variable signal to a pair of powered speakers) how does the unit feel? Knobs firm but smooth? No serious play in any switches or knobs?
I don't mean to sound like a complete fanboy of cheap gear but..... I swear the thing looks and feels better built than the esoteric d-02. it also has a similar layout inside if that says anything. I weighed this little thing at 9.3 pounds. the knobs are smooth enough and feel solid they are metal. okay to redeem myself I will say I "think" it is made in china. however the $2,000 nad m51 proudly states made in china right on the back. that means nothing is what I am actually trying to say. audio-gd is awesome too. made in china does not always mean junk anymore. my real deal with this was I wanted a half size device. in that regard I will say the McIntosh d100 is at least better sounding at $2,500usd. however the chassis is not as robust if that matters to anyone. plus I am really surprised this does not have aes/ebu. no real worries as on lower priced dacs coax and usb usually sound better. overall I don't know how msrp is $849. perhaps it will quit in six months.
wztrack, I just told you I measured +5v power on it. I guess you don't believe me. try yourself. I don't see where it is coming from either but it is present. I wish I had the service manual. I can't even see looking right at it let alone from a picture on the internet. also, it is "reference" for a lower end line of equipment. I agree it is. it is not esoteric. oh, here is an easy thing to do. cut the power wires on a usb cable and it should still work. in fact I suppose I will try that.
Edited by music_man - 2/4/14 at 7:52pm
I wouldn't say $850 puts this in the cheap gear category. For most equipment you've hit the peak of quality that the human ear can honestly perceive. That peak is really hit at about $300 for a DAC/Amp.
At 9#+ I definitely see myself picking one up soon. $700 at their warehouse site.
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I just continue to be dumfounded as to why Purrin hates this DAC so much lol!
I keep coming back to three DAC options around the $800 USD mark:
Schiit Gungnir Gen2 USB ($850)
TEAC UD-501 ($750)
Meridian Director ($700)
I am looking for a stand-alone DAC, not a HP DAC.
I'd be hard pressed to believe you could beat the low noise floor of the HRT Music Streamer HD. Lets be honest that's really the difference isn't it, low noise. The point of an expensive DAC is to put out a true analog conversion and have low noise. They aren't going to be much difference purely because of that.
Going by the way Purrin comments and rates I don't think opinion dwells in reality. He certainly fancies up his smash talk about these things.
okay I don't mean to hog this thread but I just figured out more. I have extensive test equipment but a schematic is priceless. TPS65070 seems to provide all the rails to TMS320. TPS65070 provides power to FT232 USB UART as well. power is from the ribbon cable. there is an unoccupied 3 pin molex you can see on the board. I guess they planned to use it but pulled high from the ribbon. so there you go, it has power. I already told you I measured +5 anyways. "auto" pulls down FT232 rails which is nice if you worry about noise on coax. as you said why would they go to the trouble of independent hot rails per channel and not provide measly dirt cheap usb power. linear would be tapped at the main rails obviously to the molex they did not use but I am about to take care of that right now! i have not even gotten to the i2s conversion going on! I was told I cannot share the service manual until I clear it with teac usa. sorry about that. i am sorry this is so technical but wztrack pushed me to do this. I hope this does not get deleted I realize it is not mainstream.
it would be rather impossible to host a flash drive unless that is hidden in the dsp programing. they did exploit stuff others have not on this chip like some of the filters. so who knows. I would not be surprised if it would host an ipod/iPhone. since those have the menu hierarchy and everything already set up. incredibly I do not currently have an mp3 player to try. I hope one of you guys go tries it.
btw, I just lifted the power from inside a usb hub. it still works with only data.
Sounds interesting. Does it mean, we can use signal-wired-only cable?
It doesn't work with OTG devices I checked (Note II and G2). Ipad also complains of high power consumption device.
Molex pin could be evidence that it's universal board for different devices in Teac product line. Or they use it for QC purposes.
the board is used in some Tascam products. the usb is pretty good. I got the same results with Belkin gold and audioquest diamond. that means it is really good. like -145db noise floor good. I don't know what anyone is complaining about. the thing is insane for the price. it does in fact need +5v host to start sync as do most devices. I can remove the hot after it is going but that made no difference either. not too shabby. I cannot use the molex without doing something to cut the ribbon but I am satisfied anyways. compare to bm dac2 which is considered very good. makes me wonder what if anything the ifi device will do. oh, these are scope stills of 24 bit usb input jitter in case anyone did not know. this is way below what a human can hear. this amount of jitter at least should have no bearing on sound quality. notice all the beloved dacs in this list that are bus powered. http://yourfinalsystem.com/cable-design-f-a-q/147-how-do-data-only-usb-cables-work now notice the ho1 is on that list but the ud-501 is not. bus powered dacs can be plenty good but it just so happens this one is not. with proper implementation either can be fine anyways. either can measure great. the bm dac2 is bus powered for the record. it is considered to set the bar for input performance.
Edited by music_man - 2/5/14 at 3:40am
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With some recordings I still prefer 32/384 pcm than DSD. I think it's a matter of how your system is voiced at the end. Both are excellent upscale options with this dac.
If you want something more quantifiable regarding the SQ of such a dac, German magazine Stereoplay has a review also. And if you see the scores of dacs, highest reference is 70 points. The most expensive ones score somewhere around that number And the Teac scores in 24/192 63 points. As several other dacs around 1000euro price do. That is like 90% of absolute reference sound! I know these ratings can't always be accurate cause reference points can change too. But it's an indication of great performance considering the price! Most other known dacs are somewhere in between. Can you get better? Sure for twice the cost maybe. But is just small percentages at the end. That's what highend is all about. Getting that last bit. It's a personal decision if it's worth paying for that.
In my system there is also a small but noticeable improvement going from 24/192 to 32/352.8 or 384. There's a bit more ease and finesse. And often DSD is better still.
Edited by pigunios - 2/6/14 at 5:11am