Question about CD Transport, Yggdrasil, pre-emphasis

Hi all. As I pick up more CDs to play through my TASCAM CD-500b and Yggdrasil 2A, I've landed a Pink Floyd disc (DSOTM, non-TO black face CD) that has pre-emphasis on it. Per other sources, it has SUBQ pre-emphasis, to be specific. When I listened to it the other night it sounded good but was pretty forward in parts. I never found it harsh or lacking in bass, but it did get a bit loud in the upper registers in parts.

I have inquiries into Schiit and TASCAM about this but still no real answers. Schiit has replied but basically said it's a question for TASCAM. In the meantime, I hooked up the analog output of the CD player to my line stage and can switch inputs to hear the difference. I first tried this on a really crappy metalcore recording and i can hear a difference, but it's not stark, nor would I expect it to be on such material.

But on DSOTM, the analog output of the player sounds smoother (even rolled off by comparison), has a little heftier, punchier bass and feels more "crankable" than going digital to Yggdrasil and back to the line stage. Yggdrasil sounds immediately brighter. I don't have any experience at all with pre-emphasis so I'm trying to educate myself. I have searched this topic here and in other places and I've found some general information but I can't seem to find much about it when using a CD Transport > Outboard DAC. Then there's the distinction between TOC and SUBQ pre-emphasis and it's over my head at that point.

So in short, if using a CD transport with an outboard DAC - using AES/EBU output from CD Player if that matters - how should pre-emphasis be handled? And does anyone have any similar experience with PE that they can share?

Thank you for any insight!
Todd

 

Silly question and just from a quick Google but have you read through this http://wiki.hydrogenaud.io/index.php?title=Pre-emphasis

Also there is a big difference between the output Impedance from the different outputs of the transport which might be highlighting differences.

 

I did find that article, but I appreciate you posting it because it's a pretty definitive resource. I hadn't considered the output impedances but in that case, I would expect the difference between inputs to the preamp to be a similar result no matter the disc but in the case of DSOTM, the "effect" is far more pronounced.

A poster over on SHF walked me through ripping the disc, applying SoX deemph, and burning the resultant wav/cue file to a CD-R, which I played back in the player last night. That's basically the ticket - that CD-R sounds much better through the TASCAM > Yggdrasil chain than the actual CD, and is very similar to the original CD through the analog outputs of the TASCAM. I have not tried to critically A/B the CD-R/Yggdrasil pairing vs the CD/TASCAM Analog pairing.

Either way, this has been a pretty interesting experiment.

 

I went through the whole applying de-emphasis with SoX thing and came out the other side unhappy wth the process and the sound. My solution? Get rid of any CD I had with pre-emphasis. Mind you, I was ripping all these CDs and Do not have a CD transport of any kind.

 

Are you suggesting that the DAC in the Tascam is removing the pre-emphasis, but Yggdrasil is not? Unless that is a specific feature of the Tascam, I would say you’re simply hearing more resolution and less rolled off highs from the Yggdrasil than the DAC in the Tascam. Don’t know what DAC is in there, but I’m going to guess it’s lower resolution delta-sigma that tends to have a smoother/darker signature which is why you don’t mind it. Also, Yggdrasil in general is just a bit tipped-up/emphasized in the highs anyhow, likely making the pre-emphasis even more prominent and annoying than some DACs that are a bit more neutral or rolled off on the top end.

Other than trying to strip the preemphasis from the file as you’re trying, obviously appling some EQ to the Yggdrasil setup, somewhere after the Yggdrasil in your chain, would be another approach, but that is far less than ideal.

Edit: scratch the initial point/question about about CD players analog output removing preemphasis automatically - apparently they DO!! (just read the wiki article)

 

Just about all the early CD players were designed to handle pre-emphasis. I seem to recall reading that there is a standalone DAC out there that handles pre-emphasis properly but that is certainly NOT the norm.

As time moved on and pre-emphasis was no longer used on CDs, some transport manufacturers removed the pre-emphasis handling code from their products. I am not sure where Tascam is on this.

On the transports that do handle pre-emphasis properly, it is my understanding this done prior to the DAC stage so any digital signal going out should have the pre-emphasis processed as well.