Caiman II USB vs. Spdif

[mrboonmee]

having some noise issues using the onboard (realtek) optical out from motherboard.

when looking for an USB to Spdif (coaxial) converter should it be asynchronous?

thanks for any help.

[StanleyB]

Why not try the USB out from the PC to the Caiman first?

[mrboonmee]

I thought the coaxial input sounded better in the living room. wanted to use that in the office with the Emotiva speakers. not positive if i get the noise from the USB, it's sort of been a constant issue in the office, mostly with 24bit files. sometimes it just starts making noise without anything playing.

seems to be ok in the living room lately. must be this goofy PC, that is why I was thinking about an USB to Coaxial adapter. would it matter if it was async? I am a bit confused on that, i don't want to mess things up too much.

any way to turn the gain down a bit? sometimes i want to listen at a lower volume on my super efficient Grado RS1.

thanks

[mkrzych]

I thought the coaxial input sounded better in the living room. wanted to use that in the office with the Emotiva speakers. not positive if i get the noise from the USB, it's sort of been a constant issue in the office, mostly with 24bit files. sometimes it just starts making noise without anything playing.

seems to be ok in the living room lately. must be this goofy PC, that is why I was thinking about an USB to Coaxial adapter. would it matter if it was async? I am a bit confused on that, i don't want to mess things up too much.

any way to turn the gain down a bit? sometimes i want to listen at a lower volume on my super efficient Grado RS1.

thanks

What kind of noise is it? Is a hum or clicks or something else? Are you able to hear is only on higher volume positions or also on the lower ones?

[mrboonmee]

sort of hard to explain, some pops and also like radio static? gotta be the output from my motherboard i guess. heard at all volume. thanks

[mkrzych]

Besides prior mentioned pops and clicks I would like to share with you my experience with USB and SPDIF optical version. In the past I used to have original Caiman with Gator PCB where I was using only optical, because USB there was limited to the redbook resolution. When I got Caiman II, I tried both interfaces optical and USB and at the beginning favored USB since I thought that first the implementation allow me now to use 24/96 and second players like Audirvana for instance have integer mode on Mac OSX to bypass the system audio mixer.

Now, I've been using USB over decent USB Supra Gold cable for some time on Caiman MKII powered by Anker battery pack, when I decided to check toslink again. I am not saying which interface is better, because now I think that it depends on your source hardware and possibly even on the operating system you use - that's my first observation.

Second, at least on my late 2008 Macbook, feeding Caiman MKII over USB, the sound quality is not the same - in favor to toslink. Toslink just seems to sound much better than USB. What I noticed on USB were few things:

1. The sound is "heavy" on USB and not well balanced (I mean kind of backward sounding, muddy and with weird instrument placement), I don't know if this is due to S/N and noise floor, but toslink sounds much more detailed and with better high frequency sibiliances - just more spacious and airy highs. I can't hear any anomalies in the instruments placements etc.

2. Some are talking about the jitter on optical etc, but in case of USB I think the differences in sound are more audible than theoretical only more jitter on optical. CMII USB implementation is not async and galvanically separated AFAIK - the latter one for full speed USB is rather tricky and may be costly.

3. USB sound seems to be dependant on the operating system, I tried the same A+ settings on 10.7.5 (no INT mode) and Maverick (INT enabled) with Mode 1 (colder sound) and Mode 2 (warmer, but slightly less detailed) and the first one sounded worst than on Maverick (I know that 10.7.5 is one of the worst sounding OSes).

All these observations of course may be influenced by some mental bias, but when I switched over the optical again after some time trying to figure out how the USB is sounding, the difference was rather very audible. Hard to say where the devil is sitting in, but that could be my Macbook, where in 2008 the USB 1.1 implementation was crappy or CMII where generally SPDIF (coax/optical) is better - Tenor USB PCB is rather simple and grounding of USB and lack of galvanic separation may also be noisy.

CMII does not disable the hardware volume over the USB as well (can be disabled by software), which could be also potentially a problem. I am not sure what level of signal is going from the OS towards the Tenor. Any software volume changes on your OS in that case will degrade the sound, so you must keep the OS volume at max all the time for best results. I said that USB sound "heavy", maybe because of too high signal level going from my Macbook - this is just my theory, and quite some time ago I pointed it somewhere that what I could here is that USB sound is just louder than optical.

[mrboonmee]

DAC working now!

I was only having an issue when using the PC in the office.

I bought an Peachtree TI which turned out the have the same chipset as the DAC TE7022 (i think) and same issue using that.

I came across an NuForce uDAC 2 in my drawer which has an Coaxial SPDIF out and hooked that up and working well now.

just wondering if a different USB to SPDIF converter would improve things.

right now sounding very nice, pretty happy.

Have you heard the Triangle speakers yet? I see they are in Poland. still waiting on some "EZ" models to arrive here in USA.

[Audio Advent]

These are supposed to be good according to people on DIYaudio.com and about the web:

http://www.ebay.co.uk/itm/CM6631-USB...-/160935378721 Only £29 and I think people were saying it was better than more expensive branded products like Hi-Face, although it's been around for a few years now.

Uses the CM6631 for which drivers are up to date, although I think you have to request different firmware depending whether it's for Mac or PC (but you can flash the firmware back again if you're confident in that sort of thing).

[mrboonmee]

looks like a nice piece very reasonable. listed as DAC?

sounds like it can be powered from USB or 5v external supply?

i was hoping for something powered from USB.

will be fine if it supports 192k and the Caiman ii is 96k?

is the Caiman ii USB input asynchronous?

should the USB to SPDIF converter be asynchronous?

[Audio Advent]

It can be powered from either - flick the switch for one or the other. Yeah, I guess the "DAC" in the discription is just to catch people searching.. It does do up to 192kHz (don't think it does 176KHz..) and the Caiman II does up to 192kHz I think.

There are boxes which use the more up to date version of the USB controller chip, the CM6631A but I haven't seen people's review of them that's all. There's one here for example: http://www.ebay.co.uk/itm/LJM-CM6631...-/121500418438 which comes in a plastic case?? Must be to keep costs down and appear competitive? Would have thought it would require some good shielding..

Synchronous / Asynchronous - that's a technical matter beyond me. I think there is different thinking depending on people's expertease and understanding.