Why not USB to PCM

[mbiraboy]

Hi.  I'm getting a subscription to the Naxos Music Library, so for the first time I need to worry about getting streaming audio into my UMC-200.  Naxos offers a "premium" quality stream, so I don't want to go through Bluetooth.  The obvious and much discussed method is to get a USB DAC, and run the analog into the UMC-200.

My question is this:  Since the UMC-200 has a high quality DAC, why don't I want to get a PCM stream out of my computer via some type of "USB-to-PCM converter"?  I mean, won't the analog stream be immediately converted back into digital in the UMC-200 to go through the EQ?  Don't I want to avoid this extra step?  

[jmilton]

Dec 23, 2016 11:22:00 GMT -5 mbiraboy said:

Hi.  I'm getting a subscription to the Naxos Music Library, so for the first time I need to worry about getting streaming audio into my UMC-200.  Naxos offers a "premium" quality stream, so I don't want to go through Bluetooth.  The obvious and much discussed method is to get a USB DAC, and run the analog into the UMC-200.

My question is this:  Since the UMC-200 has a high quality DAC, why don't I want to get a PCM stream out of my computer via some type of "USB-to-PCM converter"?  I mean, won't the analog stream be immediately converted back into digital in the UMC-200 to go through the EQ?  Don't I want to avoid this extra step?  

You could run the analog to the UMCs analog inputs and not re-convert to digital. If you use the USB and go into the UMC digitally, the UMC will use its DAC to convert to analog. Some may prefer the UMC DAC because they want to use EQ. The UMC 200 gives both options.

I've heard good things about the vast Naxos catalog. Glad you are into "long hair" music!

jm

[mbiraboy]

Thanks!

It's starting to appear to me that what I actually want is Chromecast Audio. It's just a question of how well the Naxos app will play with the Cast app.

[yves]

Do you mean a USB to S/PDIF converter piece? Personally, I, would stick to using the HDMI output of the computer hooked up to one of the HDMI inputs on the UMC-200, or get a separate very high quality 2 channel USB DAC to improve the sound for stereo listening, but while keeping in mind that adding such a USB DAC to the analog inputs on the UMC-200 only makes sense if switching the UMC-200 to Direct Mode before each USB DAC listening session so that, during those listening sessions, you will lose the EQ. IMO losing the EQ for stereo music listening is not a problem. In fact I find that using any kind of EQ on high quality stereo recordings just makes everything sound worse, not better. I am not the only one who thinks that.

P.S., An alternative way to use the UMC-200 in Direct Mode is to to hook up the L + R analog outputs [of the separate 2 channel USB DAC in question] to the L + R channels of the analog 7.1 Ext inputs on the UMC-200. Switching the source input on the UMC-200 to the 7.1 Ext will ALWAYS cause the UMC-200 to be in Direct Mode.

[mbiraboy]

Interesting. For me, the EQ is the whole point of having the UMC-200.

[Loop 7]

mbiraboy

+1 on the HDMI approach.

I use a Mac Mini with an XDA-2 (USB) then analog in to a UMC-200 and I think it sounds amazing.

However, I've bypassed the XDA-2, running HDMI from computer directly into the UMC-200 and it sounds really good. HDMI has so much going for it that I think this would absolutely be the best way to go. You will be impressed.

[KeithL]

If your computer supports audio via HDMI, than that is the easiest option, and supports the most features.
However, if not, then a USB to S/PDIF converter is also an excellent option.
(Converting between USB and S/PDIF, which are both lossless digital formats, is a purely digital process.)

Dec 23, 2016 14:26:50 GMT -5 yves said:

Do you mean a USB to S/PDIF converter piece? Personally, I, would stick to using the HDMI output of the computer hooked up to one of the HDMI inputs on the UMC-200, or get a separate very high quality 2 channel USB DAC to improve the sound for stereo listening, but while keeping in mind that adding such a USB DAC to the analog inputs on the UMC-200 only makes sense if switching the UMC-200 to Direct Mode before each USB DAC listening session so that, during those listening sessions, you will lose the EQ. IMO losing the EQ for stereo music listening is not a problem. In fact I find that using any kind of EQ on high quality stereo recordings just makes everything sound worse, not better. I am not the only one who thinks that.

P.S., An alternative way to use the UMC-200 in Direct Mode is to to hook up the L + R analog outputs [of the separate 2 channel USB DAC in question] to the L + R channels of the analog 7.1 Ext inputs on the UMC-200. Switching the source input on the UMC-200 to the 7.1 Ext will ALWAYS cause the UMC-200 to be in Direct Mode.

[yves]

Dec 23, 2016 15:21:19 GMT -5 mbiraboy said:

Interesting. For me, the EQ is the whole point of having the UMC-200.

The manual PEQ is terrific for multichannel movie sound. For very high quality stereo music listening through a very high quality 2 channel separate DAC, that's a whole other story... but the manual PEQ in the UMC-200 is not to blame for that, as IMO the same problem applies to ANY AND ALL TYPES of EQ, BUT... EQ for stereo music listening can still be useful if, for example, the acoustic properties of the room are so poor that very high quality sound is technically materially impossible with or without the EQ, in which case it can, and very often does, yield a significant improvement (also IMO).

[yves]

Dec 23, 2016 15:54:45 GMT -5 KeithL said:

If your computer supports audio via HDMI, than that is the easiest option, and supports the most features.
However, if not, then a USB to S/PDIF converter is also an excellent option.
(Converting between USB and S/PDIF, which are both lossless digital formats, is a purely digital process.)

Dec 23, 2016 14:26:50 GMT -5 yves said:

Do you mean a USB to S/PDIF converter piece? Personally, I, would stick to using the HDMI output of the computer hooked up to one of the HDMI inputs on the UMC-200, or get a separate very high quality 2 channel USB DAC to improve the sound for stereo listening, but while keeping in mind that adding such a USB DAC to the analog inputs on the UMC-200 only makes sense if switching the UMC-200 to Direct Mode before each USB DAC listening session so that, during those listening sessions, you will lose the EQ. IMO losing the EQ for stereo music listening is not a problem. In fact I find that using any kind of EQ on high quality stereo recordings just makes everything sound worse, not better. I am not the only one who thinks that.

P.S., An alternative way to use the UMC-200 in Direct Mode is to to hook up the L + R analog outputs [of the separate 2 channel USB DAC in question] to the L + R channels of the analog 7.1 Ext inputs on the UMC-200. Switching the source input on the UMC-200 to the 7.1 Ext will ALWAYS cause the UMC-200 to be in Direct Mode.

It's a digital process, but if your computer doesn't support audio via HDMI, then getting a whole new computer that does support it will still typically cost less than a half decent USB to S/PDIF converter.

[garbulky]

No it's not USB to PCM. It's already in PCM. You are deciding where do you want the conversion to take place. USB is the transport method for digital audio. There's no reason for it to be better or worse as far as I know than other methods. Though I haven't been thrilled with USB (so far) my experience with it has been limited. Others report nice results.

The quality comes from which unit does the conversion. For isntance if you have a sound card and it's not terrbily good, it may not sound that great because the sound card does the conversion PCM to analog. The UMC-200 may have a better DAC that does the conversion from PCM to analog.
The eq or room correction function in the UMC-200 can be used to adjust the audio to fit your room better. If your room has a bass suckout at 60 hz, you can bump it up at 60 hz to give a smoother response. At least that's the idea. Whether it works well in practice is not my forte. I personally steer away from room correction.

The UMC-200 is used for multichannel audio like surround sound movies and stuff. If you are only interested in two channel audio, there may be other options that may sound even better to you.

(For two channel only audio i,e, only two speakers)
My setup is a PC to DC-1 to XPA-1 gen 2 to my speakers.
But I have used something similar with lower cost amps with good results too.
Like a PC to DC-1 to mini-x amp on the cheaper end or a used XPA-200.
I'm not 100% sold on the unit yet but my impressions have been positive the Emotiva TA-100 to your speakers may sound reasonably good as well.

[Gary Cook]

I see 2 simple options;
1. If your computer supports HDMI output then simply use a HDMI cable to one of the UMC-200 HDMI inputs.
2. If your computer doesn't support HDMI output then use a USB to SPDIF converter and a toslink cable to one of the optical inputs on the UMC-200

Merry Xmas to all
Gary

[yves]

Dec 23, 2016 16:14:23 GMT -5 garbulky said:

No it's not USB to PCM. It's already in PCM. You are deciding where do you want the conversion to take place. USB is the transport method for digital audio. There's no reason for it to be better or worse as far as I know than other methods. Though I haven't been thrilled with USB (so far) my experience with it has been limited. Others report nice results.

The quality comes from which unit does the conversion. For isntance if you have a sound card and it's not terrbily good, it may not sound that great because the sound card does the conversion PCM to analog. The UMC-200 may have a better DAC that does the conversion from PCM to analog.
The eq or room correction function in the UMC-200 can be used to adjust the audio to fit your room better. If your room has a bass suckout at 60 hz, you can bump it up at 60 hz to give a smoother response. At least that's the idea. Whether it works well in practice is not my forte. I personally steer away from room correction.

The UMC-200 is used for multichannel audio like surround sound movies and stuff. If you are only interested in two channel audio, there may be other options that may sound even better to you.

(For two channel only audio i,e, only two speakers)
My setup is a PC to DC-1 to XPA-1 gen 2 to my speakers.
But I have used something similar with lower cost amps with good results too.
Like a PC to DC-1 to mini-x amp on the cheaper end or a used XPA-200.
I'm not 100% sold on the unit yet but my impressions have been positive the Emotiva TA-100 to your speakers may sound reasonably good as well.

There are several many valid reasons why USB can be better or worse than HDMI or S/PDIF. Modern asynchronous USB 2.0 input on a DAC is not superior by design, but by careful implementation.

Agreed that the UMC-200 has a good DAC, but not as good as my Eastern Electric MiniMax DAC Supreme. The former I use for multichannel audio content, the latter only has stereo so there's pros and cons to everything.

If your room has bass suckout at 60 Hz, then if this bass suckout is caused by acoustic phenomenae known as standing waves, bumping up the energy responsible for these standing waves will worsen the suckout. The only solution that works is to move the speakers and or listening position, as well as venture into the world of (DIY) physical room acoustic treatments (starting out by installing thick heavy bass traps, and boatloads of them, instead of making the classical error of going for thin acoustic foam products or similar sound absorbers that have zero impact on bass anomalies except for making them stand out more as opposed to help solving them).

The UMC-200 is not only used for multichannel audio, but also for a high quality analog preamp, and, depending on what it is you are looking for / what your expectations are, can even be used as a 2 channel DAC in addition to multichannel audio. But like I said, it's not as good as my...