Why buy an ERC-1 if there is a DAC coming?

[clorets123]

Excuse me if this question has been raised over and over again, but if so this is my turn to ask this question.

A couple of months ago I would not have understood the use of a separate DAC for the general population. But after reading all those threads about the UMC-1 and ERC-1 DAC, I see the importance of this process to convert the digital signal to its analog form.

Perhaps I over simplify the parts inside any CD player, but the process of extracting the raw data off the disk is the simple part of it. Any decent CD-Rom in any computer tray can do this part at a 100% accuracy, and we're talking about a 20$ piece of equipment.

So.... if I buy the new Emotiva DAC in a couple of month, I will be able to obtain the same audio nirvana the ERC is giving to you lucky owners, using my already available DVD player, PS3 for audio files or streaming, computer etc.

I would have like the ERC-1 to have a digital IN and a "External IN" button in front. This way, I could use its DAC for computer, PS3, etc.... hence well invested $399.

Since it is not possible, I do not see any real advantage for the ERC-1 against the future Emotiva DAC. I should wait for it, unless of course this logic is all crap, a likely situation

[Mr. Ben]

Not crap at all, and what you say is basically correct. There is one tiny catch though: jitter. Within a single player, they can use a single clock to run both the DAC and the CD transport parts of the player. When these two components are separated, each has its own clock, and keeping them perfectly synchronized is difficult. There are some fancy mechanisms to share a clock between devices, but that gets expensive. People will argue about how important jitter is, but at the very least, this is one area where the ERC-1 will have an advantage over the stand-alone DAC.

Some more reading on the subject: www.tnt-audio.com/clinica/diginterf1_e.html

[littlesaint]

Dec 8, 2009 19:45:38 GMT -5 clorets123 said:

...

Any decent CD-Rom in any computer tray can do this part at a 100% accuracy, and we're talking about a 20$ piece of equipment.

...

Most PC CD-ROMs are actually far from 100% accurate.

[MukAudio]

Echoing Santino, i think if CD playback was just a matter of sending some zeros and ones down the pipe then a magazine like Affordable Audiophile or Secrets of Home Theater and High Fidelity would have exposed that by now.

I'm not an EE, but as far as I know, you have to deal with jitter, noise introduced from the power supply, etc etc.

Incidentally, trying to read one of my scratched discs in Exact Audio Copy causes a lot of drama, but the ERC-1 doesn't skip a beat.


Mark.

[roadrunner]

Clorets,

The basic concept of what you say is correct, but there is a lot more to it than the broad stroke reveals. You could write a whole book on the importance of the overlooked items in the broad stroke view. Jitter, resonance, harmonics, shielding, regulated power supplies, the ability to correctly read damaged discs, etc.

The cheap transports you allude to cannot begin to compete with the ERC-1 in those important, overlooked areas. There are many very good uses for a quality DAC, but you cannot turn a pig's ear into a silk purse. A certain level of quality is required in the transport for the DAC to work its magic. Make sense?

[littlesaint]

It's not just jitter and such, but the fact that reading pits in resin with a laser at high speeds isn't as easy as it sounds.

Standalone CD players will use error correction/hiding and oversampling to compensate for inaccuracies. CD-ROMs do not.

If you're ripping CDs, and you want 100% accuracy, you should be using good ripping software that uses it's own error correction and verifies your extractions with AccurateRip (or similar) databases.

[clorets123]

Great information thanks!

If I'm lazy, I buy the ERC-1 but I am limited to CDs as a source.

If I do what littlesaint said, use a good ripping software, use AccurateRip, etc.. then I can hope to get a really good quality analog music using an external DAC, but never as good as a standalone CD player.

I now see an external DAC as a "next best thing" solution for all the digital sources of music, as compared to a simple pc audio card.

[funboy]

If you rip the CD to the hard drive, then you eliminate the possibility of jitter, I believe, making a lossless rip played through a DAC the equivalent to a CD player without the constraints of CDs. Not 100% sure about that, but a DAC seems to make much more sense then the ERC-1, except when actually wanting to pop in a CD for a listen.

[largactil]

would there be any sound quality difference between:

1. ERC-1 analogue out to UMC-1
2. PC digital out (HDMI/coax/optical) to UMC-1
3. PC digital out (coax/optical) to Emo DAC to UMC-1?

I don't quite understand whether or not a separate DAC would give better quality than whatever DAC is in the UMC-1?

[GreenKiwi]

J River Media Center is the software I've used most to do ripping. They have worked very hard to get the ripping quality to be one of the best. Their forums are as active as these ones here.

I've been a happy user since 2001

-gk

[jlafrenz]

Dec 15, 2009 22:31:32 GMT -5 largactil said:

would there be any sound quality difference between:

1. ERC-1 analogue out to UMC-1
2. PC digital out (HDMI/coax/optical) to UMC-1
3. PC digital out (coax/optical) to Emo DAC to UMC-1?

I don't quite understand whether or not a separate DAC would give better quality than whatever DAC is in the UMC-1?

The DAC in the UMC-1 is supposed to be a solid performer, but it should still be bested by the ERC-1 and DAC as they are specifically designed for high quality 2 channel. The ERC-1 vs. the DAC should be pretty much head to head, but the DAC will give you the option of connecting multiple devices.

[jannick]

Dec 9, 2009 3:39:06 GMT -5 roadrunner said:

The basic concept of what you say is correct, but there is a lot more to it than the broad stroke reveals. You could write a whole book on the importance of the overlooked items in the broad stroke view. Jitter, resonance, harmonics, shielding, regulated power supplies, the ability to correctly read damaged discs, etc.

The cheap transports you allude to cannot begin to compete with the ERC-1 in those important, overlooked areas. There are many very good uses for a quality DAC, but you cannot turn a pig's ear into a silk purse. A certain level of quality is required in the transport for the DAC to work its magic. Make sense?

But if the cd is ripped using a good ripper that performs hash verification against a db, wouldn't you end up with a data-stream that is better than or equal to what the ERC-1 can pick of the cd in real time (since your stream is bitwise perfect)? Intuitively I would also think that a DAC is easier to shield, since it doesn't have to share the box with an electric motor and the extra power supplies.

Jitter is the one area where I could see the standalone player having an advantage, but I hope emotiva are doing something smart about that ;D

Edit: Found a very interesting article on the subject of jitter. www.positive-feedback.com/Issue22/nugent.htm.

[Mr. Ben]

Dec 16, 2009 8:15:22 GMT -5 jannick said:

But if the cd is ripped using a good ripper that performs hash verification against a db, wouldn't you end up with a data-stream that is better than or equal to what the ERC-1 can pick of the cd in real time (since your stream is bitwise perfect)?

The CD standard includes extra bits of error-correction data. Any player reading the CD itself can guarantee that the data coming off the CD is correct, by performing some simple calculations to detect and recover bad bits. Except in the case of serious scratches which are too big for the error correction to accommodate, this works great, and what comes off the drive is "bitwise perfect".

[jannick]

Okay, so taken to the extreme it's the difference between mathematically provably identical to the source (hash function collisions not considered), and identical to the source with a very high probability? My point was only that the pc-based "cheap transport", should not be any worse than an erc-1 in this area.

[oppman99]

I'm not going to get into the jitter issues. All I'm going to say is that I use a computer based setup (WAV files ripped to the hard drive) with a Cambridge DACMagic and I don't feel the need to add a stand alone CD player.

[busen19]

Dec 9, 2009 8:26:03 GMT -5 littlesaint said:

It's not just jitter and such, but the fact that reading pits in resin with a laser at high speeds isn't as easy as it sounds.

Standalone CD players will use error correction/hiding and oversampling to compensate for inaccuracies. CD-ROMs do not.

If you're ripping CDs, and you want 100% accuracy, you should be using good ripping software that uses it's own error correction and verifies your extractions with AccurateRip (or similar) databases.

Awesome, thanks for the name, I just downloaded the beta version for Mac. I was using Max (also suggested by you in another posting) !!

[pultzar]

Ripping to your computer will yield a bit perfect result, just as it does when installing an operating system or any other piece of data.

You can then send this data to an external dac without worrying about pesky CDs. Anything modern and properly implemented will have a memory buffer to deal with jitter type problems.

You can always test to see if you are getting a bit perfect result from your CD player. There are some DTS tracks out there in WAV format. If you burn this to a CD and play it digitally into your processor, it will recognize the DTS and decode it (assuming the processor is expecting the potential DTS signal as it would from a dvd player). If there is a problem, you will get garbage sound. Since the decoding relies on bit perfection, any problems will result in obvious errors.

I use this method to test my playback from my PC. Lets say that Media Player fails while kernel streaming with Winamp works!

[littlesaint]

Dec 16, 2009 20:22:02 GMT -5 pultzar said:

Ripping to your computer will yield a bit perfect result, just as it does when installing an operating system or any other piece of data.

You can then send this data to an external dac without worrying about pesky CDs. Anything modern and properly implemented will have a memory buffer to deal with jitter type problems.

You can always test to see if you are getting a bit perfect result from your CD player. There are some DTS tracks out there in WAV format. If you burn this to a CD and play it digitally into your processor, it will recognize the DTS and decode it (assuming the processor is expecting the potential DTS signal as it would from a dvd player). If there is a problem, you will get garbage sound. Since the decoding relies on bit perfection, any problems will result in obvious errors.

I use this method to test my playback from my PC. Lets say that Media Player fails while kernel streaming with Winamp works!

Ripping without error-correcting software rarely results in bit perfect results. Even with error-correction, you can get interpolated corrections which is still not bit perfect. The best way to ensure perfection is to use error-correcting software that consults AccurateRip (or similar) databases and utilizes both CD-ROM drive data and the rip data (assuming your drive and the tracks are in the database) to come up with it's results.