RF Attenuators = Jitter Reducers

Do you have a SPDIF transformer in your Digital Device

  • Yes

    Votes: 40 71.4%
  • No

    Votes: 16 28.6%

  • Total voters
    56
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jkeny

Banned
2007-02-06 12:43 am
Dublin
I find it hilarious that once shortcomings of the measuring equipment are pointed out the immediate response is to look for a solution from others. I thought you guys knew something about how to do measurements or are you saying you have no idea how to evaluate equipment? Of course coming from Waki who believes that he can measure characteristic impedance with an ohmeter - enough said!

If SY could answer where/how he gets the -115dB figure for the DCX2496 we could move this along?
 

wakibaki

Banned
2008-01-08 11:51 pm
I thought you guys knew something about how to do measurements or are you saying you have no idea how to evaluate equipment?

What I'm saying is:- you have the opportunity to state the equipment with which you believe a difference is audible - or be seen to be acting in bad faith, just as you acted in bad faith when I put you on the spot the other night, and you bottled out and claimed you were tired and had to go to bed.

2 posts from ThorstenL without details of what will satisfy him as regards testing.

1 post from you without details of the equipment which you believe will reveal an audible difference.

With every dilatory post from you and your cohorts another bit of your credibility leaks away. Put up or shut up.

w
 

Pano

diyAudio Moderator
Paid Member
2004-10-07 6:05 am
SW Florida
Testing the DCX ain't hard, I've done it.

1st there is the noise issue if you want to run consumer levels.
2nd there is the spurious harmonic content of the output circuits about about 1KHz. I've posted those graphs before. They sound harsh to me, others don't notice them. The lower 1/2 of the spectrum isn't bad, really.

A better output stage will kill most of that high harmonic noise. Opamp, tube, cap, transformer, take your pick. I happen to like transformers. It's all pretty straight forward.
...
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
Testing the DCX ain't hard, I've done it.

1st there is the noise issue if you want to run consumer levels.
2nd there is the spurious harmonic content of the output circuits about about 1KHz. I've posted those graphs before. They sound harsh to me, others don't notice them. The lower 1/2 of the spectrum isn't bad, really.

A better output stage will kill most of that high harmonic noise. Opamp, tube, cap, transformer, take your pick. I happen to like transformers. It's all pretty straight forward.
...

Thanks Panomaniac,
I see you come up with a noise floor of -94dB not -115dB as SY has stated?
 
Can you comment on the official specs of the DCX where it shows the maximum noise achievable is 112dB. I would also direct you to the achievable noise floor of the D/A chip is 112dB (put this in circuit & what do you get? Now add in the input & output stage!) but you are achieving 115dB measured - please tell how this is done?

I really can't understand how a unit that is so obviously flawed is being used as the DAC in listening tests? It's input stage is not capable of handling normal SPDIF signals; it's analogue output stage has been repeatedly slated with rising distortion in HF; it uses a ASRC; it uses SMPS - I could go on.

I see Panomaniac dislikes the sound from the DCX2496
These plots show how the DCX stock output has a distortion that rises with frequency and the transformer has a distortion that drops with frequency. To my ear, this must be why I feel that the transformers remove a lot of digital glare or brittleness that I don't like.

as does Gary Pimm:
The big sound stage and spacious presentation was missing in action. The sound stage was quite narrow and shallow. Dynamics were squashed. The depth presentation barely made it the 3 feet to the back wall.

I could go on!
 
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SY

diyAudio Moderator Emeritus
2002-10-24 10:19 pm
Chicagoland
www.SYclotron.com
Can you comment on the official specs of the DCX where it shows the maximum noise achievable is 112dB.

I'm not sure how you go from a -112dB spec to "maximum noise achievable." Are you saying that their spec is a lie?

If Pano heard "brittleness and glare" or squashed soundstage and dynamics chez moi, he didn't say anything about it. His major complaint was some bass boom, which was my stupid programming fault.
 
I'm not sure how you go from a -112dB spec to "maximum noise achievable." Are you saying that their spec is a lie?
Are you saying that they state a value which is less than the maximum because they are very shy manufacturers who don't like to put their best figure in the specs in case it might be seen as boastful? :D

If Pano heard "brittleness and glare" or squashed soundstage and dynamics chez moi, he didn't say anything about it. His major complaint was some bass boom, which was my stupid programming fault.
Are you saying your unit is different to Pano's because this is his quote?
 

SY

diyAudio Moderator Emeritus
2002-10-24 10:19 pm
Chicagoland
www.SYclotron.com
You need to read the definition of "specification." If an amp is rated at 0.1% THD and it measures 0.2%, it is out of spec. If it measures 0.05%, it is in spec. I take it you don't have any background in quality control or engineering?

Pano's quote is his reaction to his unit in his system with the particular configuration he has set up. What I'm using is my unit in my system with the particular configuration I have set up.

Gary's stuff is irrelevant, not the least because there was no control in his listening, but also because we're using them in a totally different configuration. Reddest of herrings.

I am sensing that you may be getting cold feet? Would you prefer that I just pack your unit back up and send it back untested?
 
To be honest SY, I was shocked to realise that you used this as your DAC & the more I read about it the more I worry about your listening using this device. Are you also using the analogue outs of this DAC for your measurements?

I've listed some of my technical concerns above (as I said I could go on) & Pano has produced plots that show the HF distortion which is solely down to the output stage - it disappeared when the output stage was changed. He states "Getting rid of the stock output stage will not only fix the gain structure problem, it can remove a lot of high order distortion as well."

Sorry but Gary's analysis of the output stage is very revealing & hardly irrelevant.

There are many other technical analysis of the DCX2496 all point up to the same flaws both technical & sonic - these can't be ignored!

Can you borrow a decent DAC (without ASRC on the digital input) & use it for your evaluation? What's available to you locally?

None of the many users of my Hiface uses a DCX2496.

Reviews were done using PASS D1 DIY DAC, Buffalo DAC, Audiosector NOS DAC, Audio-gd DAC19 DSP, PS Audio PerfectWave DAC

End-users have used a wide range of DACS - some listed here: Hegel HD 10 DAC, Chevron Audio Paradox 8i dac, Beresford 7520 DAC, Abrahamsen V6 DAC, lots more to list.

I have used various implementations of the Sabre DACs - the Buffalo & AckoDAC

If you need other DACs that have revealed listening differences just ask I will list them
 

SY

diyAudio Moderator Emeritus
2002-10-24 10:19 pm
Chicagoland
www.SYclotron.com
One other offer I'll make to you- I remembered that I have an Echo Audiofire 2 external 24/96 DAC, courtesy of FastEddie. I can use that the same way I use the PCI-based M-Audio. I think it's a tossup from a measurements POV. That involves an extra set of analog stages (the electronic crossover), which is a direction I'm moving away from, but if you are convinced that this is somehow better than using the Behringer, I can certainly do that (while strongly disagreeing with you that this is sonically "better" to me).

The supposedly horrible PC environment is somehow evaded in my cheap HP lab computer. The M-Audio seems to be slightly better than the Echo, but they're both absolutely fine from a measurement standpoint.
 

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Pano

diyAudio Moderator
Paid Member
2004-10-07 6:05 am
SW Florida
If Pano heard "brittleness and glare" or squashed soundstage and dynamics chez moi, he didn't say anything about it.

I didn't hear any of those, no. And that's a surprising testament to the cheap electronics in the Behringer. But even on my system those faults are not something that "jumps to the ears" as they say in French. It takes a bit of time to hear them, they are subtle, but bothersome, tiresome. When they go away, it's a relief. Perhaps I would have liked SY's system even better with a modified DCX. ;) I did not get to compare it to another crossover, so how can I know? But it is still a very clean, very good system. To my ears it tends to the "cool" side of the spectrum - unlike its owner who is rather warm and fuzzy. (see avatar)

I suppose I'm in the unique position of having heard Gary Pimm's system, SY's and mine. Gary's is by far the best. The amount of detail and sense of naturalness is astounding. And it's so darn clean. Everything just sounds "right." There is so much there, there, as Gertrude might have said. The beauty of string instrument harmonics can bring tears to your eyes, just like hearing virtuoso players live. I'm working hard to achieve or surpass that system - which is no mean task. All 3 systems are far, far above ordinary. (I've heard plenty of those, too.) All 3 have their distinct personalities.
 
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