transport differences...

[Andrew Pratt]

My Sony 7700 DVD/CD player arrived on monday so last night I set to listening to two identical copies of a CD (both on CDR) one in the 7700 and the other in my Sony CX-335 300 disk megachanger. Both transports were optically connected to my Sony TA-E9000ES pre amp and set to 2 channel mode (no DSP's but sub is still enganged) The TA-E9000ES is connected to my Musical Fidelity Class A/AB 2 channel amp with a pair of Silvercat interconnects which feeds my Maggie 1.4's. Playing several tracks at that same time and switching inputs from the megachanger to the CD player revieled that I couldn't tell them apart. The 7700 has a setting to make it sound more "tube like" according to the manual and in that setting I could dectect that the top end seemed to be a little smoother sounding but when set in its defualt sharp mode I wouldn't be able to tell the two transports apart. So is this a limitation of the TA-E9000's DAC's resolving power or someother aspect of my system (or me?) in not being able to tell these two apart or is the 7700 simply not as good a transport as most people make it out to be...

It should be noted however that this listening test occured in my current room which has box's stacked everywhere (we're moving) and I might be albe to hear more sublte differences once I get the gear into its own dedicated room)

[ThomasW]

Andrew

I think you're hearing the effects of the E9000 DACs. It's a very good pre/pro but does have it's limits.

Also the 7700 has pretty good numbers for a DVD player but again it's not in the same league as some of the dedicated transports. Jon's auditioning of the Hawk Audio transport reinforces that even high-end players aren't always that good, since he thinks it betters his Sony 777. But he's pretty sure that can be fixed using the mods that Hawk did to the stock Phillips transport




theAudioWorx
Klone-Audio

[Kevin P]

Comparing two transports when listening through the digital outs is likely to sound identical, or nearly identical, since you're listening through the same set of DACs. Both transports are simply pulling bits off the CD, doing some error correction stuff and whatever else it needs to do, and then stuffs it out the digital output. Ideally a transport can do this without either introducing jitter (timing errors) or bitstream errors/alteration.

The only time such a comparison is likely to yield audible differences is:

• One transport has significantly more jitter than the other, and the prepro doesn't correct for it

• One transport does a better job of error correction or interpolation than the other transport

• Either transport manipulates the bitstream in some way before sending it to the outputs--case in point, the filter setting on the 7700.

Most differences in sound quality between components turns up in the analog side of things--the DACs, output drivers (op amps, etc.), noise/interference rejection, etc.

Is there any way to bypass the ADC/DAC conversion in the TA-E9000ES? For example, by using the 5.1 direct inputs? It would be interesting to compare how the 7700's DACs and output stages compare to those in the E9000. In my system (which I admit, is apples-to-oranges different from your system!), I get cleaner sound on redbook CDs if I use my Sony DVP-S9000ES's analog outputs into the 5.1 direct inputs on my Outlaw 1050. In my case, my DVD/SACD player's DACs are superior to those in my receiver. You have a much higher-end preamp and a different transport so your observations will likely differ from mine. In your case the digital output/preamp DACs may sound better.

KJP




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[Andrew Pratt]

Ideally a transport can do this without either introducing jitter (timing errors) or bitstream errors/alteration.

Kevin see the jitter thread I posted last week...different transports have jitter values that range from around 200 up to many thousand. The 7700 offer very low jitter at 216 (give or take a bit) but I figured the megachanger wouldn't fare as well.

I agree with you though that the DAC's affect the sound a lot more then differences in transports.

[Lex]

I agree that DAC limitations/differences are the most important consideration. But also feel that transport mechanisms are important.

That said, the 7700 has 24 bit DACs built in right? If so, and you have analog inputs on the 9000, that's what you should be doing, NOT optical. Optical to me is the worst digital transmission medium. It is a fact that optical goes through more of a transfer process than coaxial, and never, never, never would I use optical on a critical connection. As to the comparison, if optical is all the mega-changer has, use it for the comparison, but either use digital coax on the 7700 (preferably a CAT) or use the analog outputs of the 7700 with Silvercats connecting to the 9000. Ok? Nough said.

Lex

[Andrew Pratt]

Doug the only reason I was using optical for the comparison was I wanted to make things as equal as possible b/t the 7700 and the megachanger. The Megachanger only offers optial out so that's the standard I choose for the test. The 7700 does have 96/24 DAC's and as soon as I get a more suitable pre amp I'll be using its internal DAC's and by pass the 9000ES. As good as the 9000ES is for HT it lacks a analog pass though for music. Oh and Doug on a regular basis the 7700 is connected to the 9000ES with a nice digital catcable

[Lex]

Ahh, so the 9000 is a digital controller only. Didn't know that. I knew you had a CAT Digital, just didn't know what you did with it. The way you sell things, never know, lol.

Smart move on the long range plan. That's where the real differences will show up.

Lex

[Crimson]

Andrew,
A while back I did a test with a crappy Sony CDC and the 7700DVP hooked up to a 9000 via Toslink. It was quite easy to tell the difference between the 2, which honestly astounded me. I then replaced the CDC with a 3000DVP, and compared it to the 7700DVP. Couldn't tell a difference.
So I guess the moral of the story is that there has to be a really big difference between the transports for it to be audible.




Q.

[Andrew Pratt]

The way you sell things, never know, lol.

awe come on doug you know I'd never sell any of my catcables!

[JonMarsh]

I tried to post to this thread yesterday, but the site was flaking out at the time, and I couldn't post on the thread.

First, I have to concur with Lex 200%. NEVER use optical Toslink connections if coax is available.

Doug the only reason I was using optical for the comparison was I wanted to make things as equal as possible b/t the 7700 and the megachanger.

Not to beat up on you too much Andrew,
but that would be like saying you want to compare the handling of an Acura NSX and a Ford escort, so you'll put compact spare tires (you know, those skinny little hard things) on both cars just to make the comparison equal....

Everything in the chain is important; whether you can hear differences from one component to another in a specific part of the chain will be affected a great deal by the overall resolving power and cleanliness of the system. If you have an element in the chain which is the sonic equivalent of a meat grinder, it will turn everything into ground meat. Now, you can distinquish differences in the flavor of ground round, ground sirloin, and ground filet mignon, but you'll still be missing the point.

With enough problems elsewhere in the system, the beneficial affectrs of some components (which may be more subtle) can be readily masked.

To readily assess the diffferences in transports, you've got to have a good DAC. No, make that a very good DAC. Money isn't the arbitrator; freedom from readily identifiable colorations is. I know I'm probably sounding like a broken record; I'm like a sinner that's gotten religion; once I've figured out some important stuff re system configuration, I'll keep hammering away at it.

There's a reason my $3000 Sony SACD player is sitting at the bottom of the rack, not hooked up, while all my listening is done with a DAC built from a $600 kit, hooked up to a modified Philips transport. It boils down to the fact that all my CD's sound better, even old ones from the 80's, indifferent transfers from the early nineties of previously unreleased disks, etc. For the first time, I'm going through listening to all my older disks of music I love, not just disks of audiophile recordings, engineered to sound well on typical mid-fi systems.

Think about that a little bit, and the implications it has.

(spun some old Bonnie Rait disks, a couple of Basia CD's, and a recent Fiona Apple disk just last night- I'm listening to several times the amount of music I used to a year ago. )

The 9000ES is a nice unit for HT, particularly at the price you got it for, Andrew. But, eventually you can do a lot better for your music.

BTW, re the stereo slide volume control, I started going through boxes again last night, didn't find the right one yet, but I think I'm getting close!


Best regards,

Jon




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[Andrew Pratt]

Thanks for the info Jon, as you know long range plans are to use the 9000 for HT and then use the 7700 as the CD player feeding the passive preamp. Do you have any feeling as to how good/bad the DAC is in the 7700 compared to some external affordable DAC's (like say an MSB or Musical Fidelty DAC)

[JonMarsh]

Hi Andrew,

I can't really speak with firsthand experience to the 7700; I had a 7000 for a while, which is resident at ThomasW's now. It was the best DVD player of it's generation. It was not quite as good on CD's as the XA7ES. The XA7ES is substantially bettered on CD by my SCD777ES. The XA7ES, and the 7700, and the SCD777ES, use delta sigma "one bit" DAC's, running at 2.8 MHz final one bit clock. There digital filter engine does oversampling at 24 bit resultion, and that resolution is preserved in the one bit conversion, but let's be real about this, 24 bit DAC's can't resolve 24 bits, and of course, CD sources are 16bit.

Now, part of the problem is that jitter uncertainty on the bigger bits essentially wipes out the contribution of the smaller bits. The other main issue is that the last few bits are essentially in the noise floor of most anlog electronics available now. The VERY best DACs out can typically hit around 112 dB, before the following reconstruction filters and stuff. 144 db? (24bit) Fuggetaboutit!

OTOH, SN per se and 24 bitness aren't really the whole problem. There appear to be dynamic siginal issues in the analog electronics which aren't at all quantified properly by static test signals, but which are quite audible, as grain, grit, and wirey sound on transients.

After a lot of experimentation and listening, I'm coming around to the same point of view as my old friend Charles Hansen on the topic of the use of electronics with loop feedback. (Just say NO!). Charles used to work for me in the early 70's; he's the founder of Avalon Acoustics (he used to refer to me as the grandfather of Avalon because of the prototype speakers I have him in the mid 80's, and the discussions we had), and the present proprietor and chief designer of Ayre Acoustics.

Ayre Acoustics















Ask ThomasW about the difference in sound between an Aragon 8008BB and an Ayre V5. Thomas doesn't have the Ayre in an optimum system, but putting that in for the mid/hi amp on his Whispers made a very significant difference in the sonics.

That's why I'm building him an MP-DAC, so he can see what it's like to have a decent basic DAC with 24 bit resolution, low inherent jitter, and a non-loop feedback analog stage. The reconstruction filter in this DAC is pure passive; no GIC filter or conventional Sallen-Key filters. There isn't an opamp in the signal path, and only a few discrete transistors. No output coupling caps, either. Does it make a difference? You betcha. That's why my SACD player is sitting on the bottom of the rack, unconnected to anything, at the moment.

I don't recommend buying any DAC that has op amps in it. I've gone the route with premium opamps, conventional upgrade tweaks (heck, I was using OPA627's in Pro gear LONG before they became fashionable with the Assemblage and tweaker crowd in consumer audio); they are very good for what they are, as are some of the new parts (AD825, for example), but for what ever reasons which I don't claim to fully understand, they just don't sound as transparent and clean as a good circuit without a feedback loop. Local feedback (degeneration) is fine, and quite useful. But multi-stage circuits with loop feedback, no matter how much you refine them (heroic measures to reduce distortion in differential pairs, widening bandwith, etc), just don't sound as clean and natural. I've learned this my self by taking the same circuit, modifying to reduce local gain and overall loop feedback, and regardless of whay you measure, the lowest gain, minmum feedback version sounds best. There's got to be some kind of dynamic distortion apart from TIM (remember TIM, the big bugaboo of the 80s'?) that seems to be inherent to feedback loops. Fixing TIM was an attempt to fix "Negative feedback" sound colorations, without eliminating the negative feedback. I don't think it worked- it just made things a little better. A little better is not a bad thing, but a little better is not a lot better. Why settle for a little, when what you want is a lot?

I'm not talking about rolling off the highs; the Ayre V-5, for example, goes out to 200 kHz.

Anyway, end of rant.

I think going with a passive preamp/level control as an intermediate upgrade path is a good step for you. When you're ready for a DAC, maybe there will be more units available with the "right stuff".

Best regards,

Jon




Earth First!
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[Andrew Pratt]

Sounds like a plan to me...I guess I'm now in a holding pattern anyway till I get the room and IB sub built...by then hopefully you'll have something ready for me

[Kevin P]

but that would be like saying you want to compare the handling of an Acura NSX and a Ford escort, so you'll put compact spare tires (you know, those skinny little hard things) on both cars just to make the comparison equal....

Have you tried a comparison between the 7700 and the 335, using the coax Catcable from the 7700? Do you hear a difference then? I'm curious as to how much better coax IS than optical, as in is it audible?

KJP

P.S. For the record, I'm using coax for the digital in my system. Though it's not a Catcable (yet).




Official Computer Geek and Techno-Wiz Guru of HTGuide - Visit Tower of Power
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[Andrew Pratt]

Kevin I did try but with all the box's around the living room right now its hard to "critically listen" I'll try and do a better comparison in the house...hopefully I can set it up so there's no RPTV in between the speakers just to see how good it can sound.

[AndrewM]

Man, I could see that as a bad idea. I can see it now, Andrew P listens to his Maggies with nothing in between them, he loves how they sound now, so off to the Front Projector store he goes. Amazing the snow-ball effect this hobby has.

Andrew

[JonMarsh]

Yup, that's the really dangerous thing about it. Why, if the average HT/Audio nut first setup his speakers optimally in a room when they moved in, without extraneous furniture, and gave it a listen that way, the divorce rate would probably skyrocket. Or people would have to buy bigger houses, anyway.

-Jon




Earth First!
_______________________________
We'll screw up the other planets later....

[Andrew Pratt]

yeah I have the same concerns At least when I get my room set up I can pull the maggies our as far into the room as I want without having to worry about WAF or other utilitarian concerns. As I see it now the maggies will be 5 feet our from the rear wall and 3 feet in from the side walls (according to the numbers on the Cardas site). The TV's screen will be out a couple of feet so there should be quite a bit of space between the maggies and the TV...though obviously not as much as I'd like. That said since maggies don't radiate much sideways does having a TV in between them affect sound as much as a conventional speaker?

[JonMarsh]

Actually, you're right, Andrew. The side radiation is much lower- so if you pull the TV out into the room between the speakers, it coudl work very well.

-Jon




Earth First!
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We'll screw up the other planets later....

[Lex]

Why, if the average HT/Audio nut first setup his speakers optimally in a room when they moved in, without extraneous furniture, and gave it a listen that way, the divorce rate would probably skyrocket.

One look at my house, most women would run screaming. Guess that explains a lot, lol.

Lex

[JonMarsh]

One look at my house, most women would run screaming. Guess that explains a lot, lol.

Lex

Well, Lex, don't think you're the lone ranger!

The conclusion that my girlfriend and I have made is that when our kids are all grown up, we'll need a pretty good size placed, with a living room and family room separate from the dining area, because one of those will become the dedicated audio/HT room. Not that there won't be music elsewhere; elswhere, we'll let esthetics dictate choices. But not in "my" room.

But, you know what they say about war- no battle plan, regardless of how good or well thought out it is, survives contact with the enemy. :?

We've also concluded our mismatch in tastes extends in other areas, especially when I had trouble talking her into using stands for her new pair of M8's. Shee just wanted to put them on the floor. She drives an SUV, so we've summarized our basic disagreement that "I" like my speakers too high, and my car seats too low", whereas I see her the other way around.

-Jon




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