[John Ashman]

hi john,

this is where, i guess, we yust have to agree to disagree.  it's similar to the argument as to whether a preamp-based system is better than a system w/passive preamp, or no preamp.  i'm in the camp that sez active preamp is better.  yust cuz something add'l is added "in line" as you say, it does *not* necessarily mean the fidelity has been lowered.  in fact, i would submit that adding a quality preamp will *raise* the system's fidelity.

Hi Doug,
   You can disagree, but the reality is that you would be incorrect.  It *does* necessarily mean that you'll be lowering the fidelity.  It may be by very little, but you will.   The PDC-P allows you to use the entire dynamic range of the AD/DAC process, even at lower volumes where it can be argued it's not all that important.  A preamp does not, at less than full volume, you would lose resolution.  In addition, you'd still be going through the same circuitry in the DEQX you think you'd be improving or replacing.  And the added coloration increases for digital sources as you are putting in two addional and unnecessary conversion steps.  What is more transparent - one pane of 1/8" glass, or three?  You're not replacing any circuitry, you'd be just adding it. Would eating a steak before you ate a hamburger make your hamburger taste better?  At best, it would taste the same, at worst, it would hurt your enjoyment.  

It's perfectly fine to use an additional preamp if you like, but it would be redundant.  But if you do, make sure you use the regular PDC, not the PDC-P.  Just do it because it's what you want to do or because it's convenient, not because you think it will make your sound better, it won't.

[mac]

IMO, all this discussion of using "better" DAC's or using "better" preamps with the DEQX PDC is misguided.

For illustration, imagine that you just upgraded your VW to a McLaren F1 for only $3,000.  Instead of being happy with the improvement in performance, you guys are complaining that a few specs of dust on your new F1 is impacting its acceleration.

Even that analogy isn't even quite correct.  Both of those cars basically do the same thing.  They accelerate, stop and turn, although one arguably does it much better.  

In the case of comparing a DEQX PDC to an "equivalent" Marchand, Behringer, DBX crossover, there's a fundamental difference in what the units do.  The PDC is a speaker correction device that corrects amplitude and phase response (in addition to being an active 3-way crossover and room correction device).  Once you hear the effect of what the DEQX PDC does to the sound of your system you'll begin to appreciate what I'm apparently not able to convey in words.  Hearing is believing.

Sure, you might be able to eek out another 1% improvement in sound by investing in three dCS DAC's or “upgrading” the PDC’s power supply.  My point is that a bone-stock DEQX PDC will bring such a significant improvement to the sound of a properly assembled system that one could argue that it's rather pointless to discuss spending lots of additional money to hotrod it.

[JohnnyLightOn]

I think there's a difference between wanting the flexibility to use a different DAC, and wanting to use a different preamp.

A DAC is your source.  It's literally what you're listening to (other than the music).  Isn't is more than likely that the DAC in the DEQX won't be to everyone's taste?  Some people will want more musicality, others will want more detail, and so on.

If your point is that the DEQX is so good, including its built in DAC, that very few people will want to use an outboard DAC because they will be so happy with their new sound, then I have to say I'm pretty excited about this technology and imagine it will become prevalent in the high end world in the future.

[John Ashman]

A DAC is your source.  It's literally what you're listening to (other than the music).

You're assuming that a DAC improves the sound.  It does not.  It tries to preserve the sound.  Any good component degrades the sound only slightly, rather than obviously.  Adding a DAC not only adds more coloration to the mix, but it adds another AD and DA conversion that would be totally unneccessary.  

Adding a DAC would be like adding more pepper to eliminate the flavor of pepper in your food.  Totally illogical and totally ineffective.

[ted_b]

Mac,
I've tried to stay pretty quiet on this due to my "scratching the surface" evaluation, but your last comments about the McLaren F1 and the DEQX's DACs require a response.  

I have said many times that the DEQX is a tremendous product.  I have also said many times, or agreed with your thoughts, that I used only 20% of what the DEQX has to offer (room correction, dacs).  I did not use the crossover technology (the DEQX's biggest value prop) cuz I was single amp, and did not use the speaker correction to its greatest effect because I tried to fix a multi-driver RM/X without getting into it's specific driver corrections.  All I got to use in those 30-45 days was room correction and the bypassed mode of using the DEQX's DACS.   In terms of room correction the DEQX is very sophisticated and uses the latest technology.  In terms of the DACS, that's something far different.

This whole thread has been about those of us who believe audio life is about tradeoffs, debating with the other side that says the DEQX can not be improved and for $3k you get State of The Art everything (I'm being facetious here, but the point about improvement is what I'm alluding to).  It may very well be that the audio signal path is made up of 100 demons, and that 80 of them live in the speaker and it's distorted crossover networks.  It may be a true statement that says if you slay those 80 demons, you could put an Audio Alchemy 1993-era DAC in this thing and it would beat all others who only addressed the 20% left.  If that's what you are saying, then debate that.  But to say that the DACS in the DEQX are state of the art, and that they shouldn't be on anyone's radar is missing the point about DACS.  They are the sources engine, and require some attention, especially if you want to eek out that last few percentage points (+ or - 20).  Why would anyone want to let this thing sit at only 80% of potential, even if 80% beats the competition by 50%.

I say all this cuz all I got to hear were the DACS, and they aren't that good.  My system is pretty damn resolving and I heard, and several friends heard, average DACS, not nearly the resolution of what I currently use.  Others are saying the same thing.  Ask Overkill, ask other speaker vendors (I won't name other names since they haven't gone public with their remarks yet).  

If the DEQX were to develop a swappable DAC board, and a real power supply they would easily address the last 20 or so demons.  I really wish I could have heard those 80 demons falling to their death, but why, for those who have heard,  be complacent at stopping there, or worse yet, be blind to the fact that they may exist.

Ted

[mac]

A DAC is your source.  It's literally what you're listening to (other than the music).

A DAC isn't a "source".  It's a converter.  It accepts a signal from a digital source and converts it to analog.

Isn't is more than likely that the DAC in the DEQX won't be to everyone's taste?  Some people will want more musicality, others will want more detail, and so on.

If your point is that the DEQX is so good, including its built in DAC, that very few people will want to use an outboard DAC because they will be so happy with their new sound, then I have to say I'm pretty excited about this technology and imagine it will become prevalent in the high end world in the future.

I guess my analogy wasn't convincing.  In any event, the DAC's in the DCX PDC are "audiophile approved".  And, for the record, I'm not aware of any current PDC user that feels his DAC's are the limiting factor in his system.

If you're of the mindset where you prefer your VW to the McLaren because the VW has nicer wiper blades than the F1, the DEQX PDC may not be the product for you.  It does so much more for the sound of your system than any whiz-bang DAC ever will.  

It's unfortunate that Ted only got to utilize 20% of the PDC’s capabilities.  Had he consulted me with his intentions of how he'd be using it prior to purchase I would have strongly advised him to pass.  His speakers are not what I consider optimal candidates for DSP correction and he was either unwilling or unable to use the PDC in multi-amp mode.  

Btw, the DAC's in the PDC are at least as good sonically as the PT P-3A, which I've owned and have experience with.  There are a lot of reasons why loudspeaker manufacturers have a built-in prejudice for accepting the PDC and most of those reasons should be apparent to the astute.

Cheers, mac.

[John Ashman]

Ted, while I agree that the DEQX may not be the equivalent of a $3000 outboard DAC, it isn't because of the actual DAC chips, those are quite excellent.  Top end 24/96 DACS today are dirt cheap.  And I mean dirt cheap.  That is because they are now used in everything, not just CD players.  

I think you could argue that the analog section isn't up to exotic level, it can't be.  If it were, it would be a $6000-$7000 product.  That's why I say that you might take 1 step back, but you take 20 steps forward.  I think if you had tri-amped your speakers and, preferably, had more appropriate speakers for DEQX, the 19-step net gain is absolutely worth it.  

And that's why I'm going to find you the Cleveland Xd dealer and make you a true believer

Ted on his system -
Ted's system on 20% of DEQX -  
Ted on Xd -  

[ted_b]

Mac/John,
I appreciated all the advice you gave me; and agree it was after I decided to evaluate the DEQX.  Mac, you were spot on with my difficulties with the RM/X's.  

The message here is getting pretty clear.  First, there are a whole host of speakers that are not good for the DEQX's speaker correction, and for that reason alone the DEQX is primarily the bargain for speaker design and DIY folks in its inital rollout.  Second, the advantages of true speaker correction are best found with amp-per-driver configurations.  Third, the gains found with perfect speaker correction far far outweigh any shortcomings in the product architecture, including switching power supplies and averge analag/digital stages.  But it's the final message that bothers me: there is no need to improve the DEQX (as in point 3); doing so would be fruitless.

Ted

[denverdoc]

To those not satisfied with the DAC:

Why not just get the digital out option, use your own DAC and attenuation, and call it good?

John

[mac]

First, there are a whole host of speakers that are not good for the DEQX's speaker correction...

Ted, I wouldn't go that far.

I don't mean this to sound condescending, but if you figure out the reason why there are at least a few speakers that are not optimum candidates you'll learn a lot about loudspeaker design.  The gained knowledge might also influence your choice of future loudspeaker purchases.

Most of everything else you said I'm in 100% agreement with.  The exception is "no need to improve the DEQX".  While I have tried to get the point across that while the audiophile quotient of the DAC is important, it's way down on the list of "things that need to be improved" with the PDC.  Ditto with the power supply.  I'd love to have the hi-res software/firmware option available.  It'd also be cool if DEQX offered a lower cost DAC-less PDC for those who want to use their own 6-channel DAC.

Cheers, mac.

[John Ashman]

Ted,
    I agree with everything you said above and I don't think it's impossible to make the PDC better sounding if you throw enough money at it.  Perhaps that will occur naturally as the price of the other componentry comes down, sales levels go up and after some of the research behind the product is paid for.  HOWEVER, what you're saying lacks perspective.  

Let me ask you this.  Compared to the analog section in the PDC, how much phase error do your speakers induce?  How about time distortion?  What about THD?  What about transient response?  How much damage do you think it does to send a signal through a bunch of capacitors, inductors and resistors.  Do you think the crossovers in your speakers could have better parts?  How can you own a product that does this much damge to your sound, if the DEQX is so inadequate?  

Buying a DEQX and not using it as a crossover is like buying an Audi Quattro and never taking it out if the roads aren't totally dry, then complaining that it adds a little weight.  

Don't get me wrong, I understand what you're saying and I can understand that you'd be more tempted if had a more exotic analog section and/or power supply.  HOWEVER, I could equally argue (and did in advance) that your speakers aren't ideal for DEQX and not tri-amping with it is a total waste of time.  So, while you can nitpick it as a DAC, you never did use more than a small part of what it can do and you really, as of yet, haven't even gotten a sense of what it could do and DOES do in a properly set up system.  

High-end audio, as it is currently done, is like taking a shower, getting a nice hair cut, putting on your favorite cologne, putting on your favorite clothes (your electronics) and then jumping into a mudpuddle (your speakers).  DEQX pretty much allows you to jump over the mudpuddle.  If you're too busy obsessing about whether you might mess your hair in the jump, you might just end up right back in the mudpuddle.

[John Ashman]

BTW, the percentage of people who expressed concern about the ADC/DAC process and/or the digital amplifiers in NHT Xd - about 50%.  

The percentage of people who expressed any concern after hearing Xd - 0%

That's because it's so well executed that,  if there is a step back, you just can't hear it over the 20 steps forward.  But then again, maybe there's no step back at all and you're just "concerned".  You know what happens when I think I came in contact with someone who has the flu?  Or if I think I ate tainted food?  I develop low level symptoms of sickness.  It's natural.  What happens when I realize that those symptoms aren't getting worse?  They go away.  I once thought I came in contact with an animal that had lice.  I couldn't stop itching.  I was totally aware of every feeling on my skin.  Did I have lice?  No.  But I was *concerned*.  That's the way the mind works.  And, to be honest, that's exactly how about 90% of "high-end" works too,.

[Davey]

John,

How many dealers are there for the DEQX in the States, and what (based on your experience) would be their policys on in-home auditions or 100% money-back after a few months or so?  Both you and Mac have advocated that the DEQX needs to be experienced in a users own system to really appreciate the performance.  I believe you guys, but can you see the quandry this puts many potential customers (like myself) in?  There's no way I'm going to plonk $3000.00 for a gadget that I can't evaluate beforehand or trial-use for a period of time.
I believe THIS is the basic problem with the DEQX....not this DAC or that DAC.
So, assuming the DEQX is the greatest thing since sliced bread technically, it won't matter because of the limited availability and high price.
Can you see what I'm getting at?  Are there more dealers than I think, and are their return policies better?  Or am I just the oddball and there are many potential users out there who are willing to lay down big bucks on a leap of faith?

Mac, sorry.  I broke my rule again and commented in a DEQX thread.    I'm slapping my own wrist right now.

Cheers,

Davey.

[John Ashman]

And don't forget, as was mentioned by DenverDoc, just add the digital output option, a Meridian G91, 3 DACs and a McCormack 6-channel preamp and then there is no degradation whatsoever - for only about $10,000 more!  

[John Ashman]

John,

How many dealers are there for the DEQX in the States, and what (based on your experience) would be their policys on in-home auditions or 100% money-back after a few months or so?  .

I can't speak for other dealers, but I personally do a 60-day, full money back guarantee.  You're absolutely right - it needs to be auditioned first hand, it's not for the feint of heart, you need so explore it and understand it fully and, for better or worse, that takes some time.  And I don't blame people who feel the need to return it, it's something of an audio lifestyle change and the right speaker IS important.

[doug s.]

Hi Doug,
You can disagree, but the reality is that you would be incorrect. It *does* necessarily mean that you'll be lowering the fidelity. It may be by very little, but you will. The PDC-P allows you to use the entire dynamic range of the AD/DAC process, even at lower volumes where it can be argued it's not all that important. A preamp does not, at less than full volume, you would lose resolution. In addition, you'd still be going through the same circuitry in the DEQX you think you'd be improving or replacing. And the added coloration increases for digital sources as you are putting in two addional and unnecessary conversion steps. What is more transparent - one pane of 1/8" glass, or three? You're not replacing any circuitry, you'd be just adding it. Would eating a steak before you ate a hamburger make your hamburger taste better? At best, it would taste the same, at worst, it would hurt your enjoyment.

It's perfectly fine to use an additional preamp if you like, but it would be redundant. But if you do, make sure you use the regular PDC, not the PDC-P. Just do it because it's what you want to do or because it's convenient, not because you think it will make your sound better, it won't.

hi john,

if i were to get a deqx, it would certainly be the pdc, not the pdc-p.  because, even tho you state that my analog preamp would be a step backwards, adding another layer, the proof is in the listening.  and, i've heard more than one system, using s.o.t.a. cd source, specifically designed to be used *without* a preamp, that sound better when used w/a preamp.  others besides myself have come to the same conclusions.  of course, i agree that there *are* folk who prefer eliminating the preamp.  perhaps the preamp *does* add distortion.  but if it sounds more like music, so what?  after all, isn't that the goal - sounding like music?  system synergy can play a big part, here.  as i said, we yust have to disagree on this issue.  

regards,

doug s.

[John Ashman]

Of course, Doug, I'm speaking objectively, not subjectively.  I'm just saying that I wouldn't assume subjective superiority when, logically, objective performance would be lowered.  In the end, you have to do what sounds best to you, but don't assume that adding a DAC or a preamp to a PDC will improve the sound.  Objectively, it can't, so it could be an expensive mistake to assume a subjective upgrade where none may, and probably doesn't, exist.

[doug s.]

Of course, Doug, I'm speaking objectively, not subjectively.  I'm just saying that I wouldn't assume subjective superiority when, logically, objective performance would be lowered.  In the end, you have to do what sounds best to you, but don't assume that adding a DAC or a preamp to a PDC will improve the sound.  Objectively, it can't, so it could be an expensive mistake to assume a subjective upgrade where none may, and probably doesn't, exist.

hi john,

yes, i understand your point.  but realize that i love my preamp, & have no intention of ditching it.  i am yust looking to get the best possible loudspeaker/crossover combination.  i also know that, while logically, the addition of a preamp should lower objective performance if it's not needed, the reality in many (if not most?) cases yust doesn't follow.  if, objectively, the huge speaker/x-over upgrade still leaves something on the table, cuz i have decided to stick w/my preamp & associated sources, oh well!  

i also think that if ted b had gotten a pdc, instead of a pdc-p, & used it as i want to - in a tri-amped set-up, *only* as a x-over, w/speaker-room correction capability, he'd *still* be using it, & wouldn't be able to go back to a system without it!    of course, this is mere speculation on my part, having not had the pleasure of trying it...

regards,

doug s.

[denverdoc]

... i also know that, while logically, the addition of a preamp should lower objective performance if it's not needed, the reality in many (if not most?) cases yust doesn't follow.  if, objectively, the huge speaker/x-over upgrade still leaves something on the table, cuz i have decided to stick w/my preamp & associated s ...

Maybe, all I know is I am ditching any unnecessary analog paths in my chain, and will be giving the UCD Hypex a long look in favor of the Classe 1000 watt MB's. And this from a former tube/vinyl guy! Not that I have heard that many top end DACS in my home, but the sound as suggested by Mac, John, myself,  et al is so friggin good, I just don't see the need to upgrade, at least for now. These slight changes in hue pale in comparison to the overall gains in coherency.

What has not been mentioned is the startling increase in jump factor, owing I guess to having everything lined up properly in the time domain--dynamics like I have only heard live. Actually scary at times!

John S

[mac]

... all I know is I am ditching any unnecessary analog paths in my chain, and will be giving the UCD Hypex a long look in favor of the Classe 1000 watt MB's....

I'm sure your review of those will be quite positive too.    

Btw, just to clarify, the Hypex amp modules aren't technically considered digital.  They use a conventional analog input stage and PWM output stage.