Adcom GDA-700 Digital to Analog Converter My First Impressions

[EdwardGein]

Got this for around $250 on Ebay & it arrived today. I was hoping to hook this up with the Pioner PD-59 player I also bought, but it's on transit. So I connected this to my Denon 31 DVD player by optical cable (I hope to try coaxal too which I don't have yet) & then connected it to my Denon Recevier by 2 Monster THX Analog Interconnects I had on hand. It also does XLR jacks which I don't know right now what they are. Anyway, I did my crummy Beatles CD testing: 1. I listened to the same CD from the Adcom to the Denon, 2. Then 2 analog interconnects from the DVD straight to the Denon & finally 3. Optical connection from the DVD to the Denon. I found the Adcom seemed to smooth the sound out a bit & give it a little more depth & prefered it to the optical sound which I prefered to the straight analog sound.
At this point, while I can't say I heard a night & day difference, I did hear what I think is at least a $250 difference for the better. I'll go through a similar process when I get the PD-59 CD player in. Will also report Paul PCI's opinions on this as well, even if its different then mine. He might be able to better articulate the differences which I'm having trouble clarifying. I haven't tried this for DVD's & probably won't even use it when playing DVDs.

[N. Abstentia]

So you hooked up the Adcom DAC with an optical cable, and it sounded better than your Denon player did when connected either with digital or analog?

Very good. That means the Adcom DAC is higher quality than the DAC in your DVD player, and the DAC in your receiver...which it should be since the Adcom DAC alone costs more than than your entire DVD player!

Sounds like you're getting there, but the Pioneer player won't sound a bit different in that setup. Since you're using the optical cable you're bypassing the internal DAC. What you want to do when you get your Pioneer is hook it up analog and A/B against your new Adcom setup.

[EdwardGein]

If I get better sound by connecting analog cables only, of course I'd do that Presently I don't going from my Harmon Kardon 31 DVD player to receiver, it sou nds better with an optic connection. When I connect the optic from the DVD player to the Adcom & use its analogs out (there is no digital out) it sounds better as well. The Harmon Kardon sold for $350 new & could be obtained for around $275 new with shipping online. THe Adcom originally retailed for around $1,000 but I got it used in excellent condition for around $250 or so with shipping.

[paul_pci]

Because I can do this diplomatically: The Adcom DAC woudn't have a digital out because its sole job is to convert digital signals to analog signals that can then be amplified and sent to the speakers. There would be no point in having a digital out because then it would be doing nothing, that is, it wouldn't be doing anything different that merely connecting the player to the receiver via optical would do. Clear?

[N. Abstentia]

If I get better sound by connecting analog cables only, of course I'd do that Presently I don't going from my Harmon Kardon 31 DVD player to receiver, it sou nds better with an optic connection. When I connect the optic from the DVD player to the Adcom & use its analogs out (there is no digital out) it sounds better as well. The Harmon Kardon sold for $350 new & could be obtained for around $275 new with shipping online. THe Adcom originally retailed for around $1,000 but I got it used in excellent condition for around $250 or so with shipping.

Okay so that means that your receiver has a better DAC than your Harmon Kardon, and the Adcom is a better DAC than ALL of them...which it should be. NOW you're doing something that makes sense.

By using the optical cable from your CD player to the Adcom, you're bypassing the DAC in the CD player, and you're not using the DAC in your receiver....the only DAC you're using is the Adcom, and that's is sole job so it should sound better than all of them.

[EdwardGein]

As I said, if something gives me better sound by one method instead of another, I'll do that. I never claimed that optical is the end all be all, just with my present system of a Harmon Kardon 31 DVD player attached to a Denon 3801 Receiver, I got a better sound connecting this DVD player by optical cable to the receiver then analog cables.

[N. Abstentia]

Well just to clarify, it has nothing at all to do with an optical cable. The cable is simply a means to transfer the 1's and 0's..as you're finding out now with an external DAC. What matters is the quality of the DAC, which you're also finding out.

You got a better sound by hooking up an optical cable before because your receiver has a better DAC than your player. Now the Adcom is the best of the bunch.

[EdwardGein]

Not arguing with you there but you may not like my next thread.

[N. Abstentia]

Well...I thought you were on the right track. Now you're back to Cluelessville....population = you.

[EdwardGein]

The thing I'm amazed with this forum is how the know it alls totally dismiss the listening experiences of someone who's heard the actual product when they themselves haven't.

[N. Abstentia]

Well if you knew what you were doing maybe we would listen. Here's what you're saying:

"I use an optical cable, so I'm only using the DAC in my receiver. The digital signal coming from one player sounds so much better than the digital signal from another player!"

Does that not sound asanine to you?

Do I need to simpify it for you? Okay, here it is dumbed down:

"I've got a green garden hose and a yellow garden hose which are hooked to the same spigot. The water tastes so much better from the green hose that it's just incredible!"

You WERE on the right track. You bought a nice DAC to bypass the crappy DAC in your player and it sounded nice. It sounded better than the DAC in your receiver. But then you bought another player and insist on using the optical output which BYPASSES the DAC in that player and you're BACK to using the one in your receiver. So what you've done is bought yet another player that will sound exactly like all your others because you want to use an optical cable...

..WHICH IS FINE. Using an optical cable is fine. If that gives you the best sound then use it. However please UNDERSTAND WHAT YOU ARE DOING. You are NOT hearing the PLAYER. You are hearing your RECEIVER.

[bfalls]

Are you saying all CD/DVD optical outputs are identical and present identical information to the DAC in his receiver? Bits is bits? That a Denon uses the same optics, laser alignment servos, signal processing, optical connectors as the HK, or the Adcom? Interesting. What about players which use multiple lasers or multiple lenses to be compatible with various formats. What about user adjustments within the player? Some have their own surround or other processing (BBE, SRS). Isn't this done within the digital domain and available via digital output. Even using the optical with an external DAC and analog to the receiver would still sound different between players unless all digital outputs are identical. What about source material recorded at 24 bits instead of 16? If the player isn't 24 bit capable will its 16 bit or 1-bit MASH (are they still out there?) outputs look the same to the receiver's 24 bit DAC? You say he's not getting "it", but all he's saying is he hears a difference. Something you can only comment on "logically", where he's receiving superior evidence from his ears. He's not saying a slight difference, but a $250 difference. For some that difference could relate to a different power cord, different interconnects, "pixie snot". For him it's a player. What's the big surprise?

[N. Abstentia]

I guess you have a point...maybe I shouldn't be surprised taking into consideration some of the stuff Ed has done in the past.

[Quagmire]

And so having said all of that... are you saying that by using a different means of transferring this digital data from one location to another, the mechanism by which this data transfer takes place will alter the signal? Something more or less than the digital signal will be sent?

It's fine for Ed to share his opinion regarding his listening experience. It is also fine for folks to help him understand the technology and what is actually going on inside the equipment. Ed came to an audio forum; he shouldn't be surprised to get responses to those things he has posted which require an explanation -- even something like signal processing within the digital domain. Isn't signal processing by definition an alteration of the signal? But once that processing takes place within the player, what gets sent through the digital cable other than the processed digital signal? What is transferred via the digital cable other than digital information... data for lack of a better word? In fact, you can forget the rest of my post if you want, just answer that one question.

Q

[N. Abstentia]

Not sure who you were asking, but yes...a digital data stream is just that...a stream of 1's and 0's. Unlike analog, there is nothing in between. Digital has two states..on or off. Either there is a signal or there is not.

[Quagmire]

I was responding to bfalls last reply to you. I hope he gets around to answering my question; although in a sense, it was rhetorical in nature. I know it may seem this way because I get around to posting here so seldom, but I am actually not a newbie.

Q

[bfalls]

I'm not sure exactly what you are talking about, but I'll try to answer what I think you are trying to ask. Of course, what you will get out of the coax cable will be a digital signal, but all digital signals are not created the same. In the case of 16-bit vs 24-bit you have 8 more bits to help the D/A converter smooth the reproduction of a digital to an analog signal. I don't have a calculator available, but if you compare the number of variations from 16 to 24 bits it's thousands if not ten thousands. Also if there's user controls on the DVD player there can be differences in the way the Dolby chipset handles the signal or the internal processing changes the signal. You can say it all comes down to '1s' and '0s' but there may may not be the same number or configuration. The fact that Ed hears a difference should be enough. Florian, for example, can hear the difference between cables (variations in the capacitance, inductance and resistance of different wire compounds and configurations), or a difference in a DVD/CD transport (speed variations, transistor/tube outputs, etc). Why is it so difficult for you to believe Ed can hear a difference between an NAD and a Denon or HK.

I'm not sure how much you know about digital signal processing, but there's a whole lot more going on than bits in and bits out. A DVD signal for example has compression, interlacing of bits (helps with error correction if there's a scratch, keeps too many consecutive bits from being in the same location), error correction checksums generated, quantization, buffering, etc... To say all digital outputs are the same is like saying all amplifiers sound the same or all cables sound the same (not getting into this argument). Instead of me supporting my position, which is saying Ed knows what he's hearing, explain to everyone here why he shouldn't. Digital comes as close as ever to perfect duplication. It's why there's so much controversy and why the big music companies are so protective of their intellectual property. But it's not so perfect differences can't be heard.

[Quagmire]

Talk about "give em the ol' razzle dazzle!" The resolution of the recording; be it 16 bit, 20 bit, or 24 bit, does not change the resolution of the storage device. If it is Redbook CD then it is 16 bit. All PCM signals from CD's and CD players will be 16 bit.

Any internal processing is an intentional alteration of the digital signal, but once altered, the signal sent is the signal received. If Ed likes to listen to music with a DSP mode like "Hall" that is his preference. But what is being discussed is the ability of one player to send a superior or inferior digital signal, and that these differences in the digital signal can be heard. So your internal processing argument is comparing apples to oranges.

When Florian can correctly identify a burned CD-R copy from the original CD under blind conditions to a statistically significant degree, then come talk to me.

"The fact that Ed hears a difference should be enough."

If it is enough for Ed then fine. To suggest that his experience should be evidence enough to convince others is not enough.

Q

[EdwardGein]

This is a general comment not directed at any particular person: Some people here have posted comments that CD's played on DVD players will sound different then the same CD's played on CD players. Therefore if one is in agreement with this theory, then ifso facto, a CD will sound different played on a DVD & CD player when connected digitally.

As an aside, I listen on all channel sound, not "Concert" or any other DSP sound, for CD's & all that does is not actually reprocess the sound per se but play the same left & the same right in both the front & rear speakers & a mono combination of the left & right in the center.
Too me this gives the sound more depth but doesn't actually change what is suppose to be played in the left & right channels.

When I played a few CD's, both older 60's stuff & newer modern recordings, through the Pioneer PD-59 & the Harmon Kardon 31 DVD player via optic cable, both on my Orb Speaker System & Paul PCI's B&W speakers, Paul also heard differences in sound particularly in regards to the brightness of sound & vocals. Paul wouldn't characterize these as night & day differences, but they were significant enough for me to buy & keep the Pioneer PD-59 to use as a CD player with an optic connection.

Anyway, the ultimate authority for anything is of coursre you. All I'm saying is you shouldn't rule something out 100% unless you've heard it for yourself & if its a matter of buying something that might not work out, if you can resell it for a minor loss, it might be worth taking a chance on.

[N. Abstentia]

As an aside, I listen on all channel sound, not "Concert" or any other DSP sound.

You have zero clue still, don't you?

'All channel sound' is a DSP. It's fake. Digitized. Matrixed.

[EdwardGein]

Your a fake I thought Scott Baio was the Anti-Christ but now I realise it is you!

[Jim Clark]

This is a general comment not directed at any particular person: Some people here have posted comments that CD's played on DVD players will sound different then the same CD's played on CD players. Therefore if one is in agreement with this theory, then ifso facto, a CD will sound different played on a DVD & CD player when connected digitally.

As an aside, I listen on all channel sound, not "Concert" or any other DSP sound, for CD's & all that does is not actually reprocess the sound per se but play the same left & the same right in both the front & rear speakers & a mono combination of the left & right in the center.
Too me this gives the sound more depth but doesn't actually change what is suppose to be played in the left & right channels.

When I played a few CD's, both older 60's stuff & newer modern recordings, through the Pioneer PD-59 & the Harmon Kardon 31 DVD player via optic cable, both on my Orb Speaker System & Paul PCI's B&W speakers, Paul also heard differences in sound particularly in regards to the brightness of sound & vocals. Paul wouldn't characterize these as night & day differences, but they were significant enough for me to buy & keep the Pioneer PD-59 to use as a CD player with an optic connection.

Anyway, the ultimate authority for anything is of coursre you. All I'm saying is you shouldn't rule something out 100% unless you've heard it for yourself & if its a matter of buying something that might not work out, if you can resell it for a minor loss, it might be worth taking a chance on.

First, I see you didn't live up to your promise to leave. Actually, I consider that a good thing for a number of reasons. It would be a shame to drive someone away. Debate is good and at the very least entertaining. You provide me with a great deal of entertainment and I don't mean that in a negative way. I'm glad you're still around.

This post is actually fairly cogent, though I still believe you're incorrect. I don't see where you account for any variables, volume differences in particular. I had a great deal more typed, but it was just too confrontational and not worth it. All I'll say in conclusion is that you say not to rule something out and I say you don't place enough value on common sense.

Regards,
jc

[EdwardGein]

In all respect to you, Jim Clark, when we were comparing CD audio quality between the Harmon Kardon 31 DVD player & the Pioneer PD-59 CD player, we played the exact same beginning part of the same CD tracks within a 1/2 a minute to a minute of each other, at the exact same settings connected to the receiver both by identical optic cords. Paul PCI heard the same basic differences I did. We did this several times to several tracks. We then did the same process using his his system as well (I'm not sure if the optic cables were identical) at his place & the results were similar. I'm not saying the differences were night & day but there were differences & I don't see any variables in the equation to account for them other then they were played on different equipment.

[shokhead]

You should get the polk R30's on sale at frys for 40 bucks each and if they didnt work out i bet you could sell them on e-bay and at the worst break even. They also have the R50's for 70 bucks.

[Eric Z]

You should get the polk R30's on sale at frys for 40 bucks each and if they didnt work out i bet you could sell them on e-bay and at the worst break even. They also have the R50's for 70 bucks.

i know this has nothing to do with this thread, but...

my friend wanted some dirt cheap speakers and i recommended the r30s last year. i was actually pretty impressed- they weren't absolutely fantastic, but well worth the $40 imo!

i still recommend these to people who want a step above a basic yamaha, pioneer, sony speaker.

[GMichael]

In all respect to you, Jim Clark, when we were comparing CD audio quality between the Harmon Kardon 31 DVD player & the Pioneer PD-59 CD player, we played the exact same beginning part of the same CD tracks within a 1/2 a minute to a minute of each other, at the exact same settings connected to the receiver both by identical optic cords. Paul PCI heard the same basic differences I did. We did this several times to several tracks. We then did the same process using his his system as well (I'm not sure if the optic cables were identical) at his place & the results were similar. I'm not saying the differences were night & day but there were differences & I don't see any variables in the equation to account for them other then they were played on different equipment.

Hi Ed,

So tell me, how do you like how it sounds? Are you happy with your setup the way it is?

[EdwardGein]

For me personally, the Pioneer PD-59 CD player is a big improvement over my CD sound coming from the Harmon Kardon 31 DVD player. Bare in mind that I mainly listen to rock & blues remastered recordings that were originally recorded in the 60/70's & maybe what I'm saying won't be as applicable to recordings made much later on. Also as I'm kind of a fanatic on these recordings, I might notice or be aware of certain things that a casual listener who wasn't a fanatic might not notice. There was nothing wrong with the CD sound from the Harmon Kardon 31 DVD player & I couldn't quite put a finger on what I wanted to improve till I heard the PD-59. The main difference is the CD sound from the Harmon Kardon was too bright compared to the Pioneer PD-59 which sounds more richer, fuller & natural. I think you can notice the biggest improvements in regards to vocals. The PD-59 seems to even out or smooth out the recordings & their balance & the HK has a rougher edge sound. This is when listening to both through optical cables. Paul PCI heard both & I think he basically agrees with me on this. Our main difference is he thought the Adcom GDA 700 DAC improved the PD-59 & I actually preferred it without the GDA-700. We both were in agreement that the GDA 700 definately improved the HK CD sound. I didn't see Analog cables improving the sound of the PD-59 or the Harmon Kardon, in fact I think Analog cables for the HK make it sound worse. I'm more then happy with the DVD audio & picture though on HK 31 DVD player so I'm now going to use the PD-59 for CD's & the HK strictly for DVDs. I liked the PD-59 so much I was looking for a second one for my bedroom system. Someone I was in contact with had a Pioneer PD-65 for sale, which is suppose to sound even better & because the door does not always open & close electronically & you have to do it mechanically half the time because of some problem, even though it still plays & sounds fine, he sold this to me for $250 which is about 50% off if it didn't have the problem with the door. As he said, its been like that for over a year & doesn't affect anything else, I thought this was a good deal, other then having to spend 10 seconds or so opening & closing the door. On this model though, as opposed to the PD-59, I was told analog cables do make a big difference, so I'm keeping my fingers crossed. It should arrive in the next 2 weeks or so. If someone is going to look for a "Vintage" CD player, I'd recommend using the reviews here & elsewhere if you can find them. I originally was not planning to look for a CD player & was going to get the Denon 2900 Universal player which got excellent reviews but I was more then put off when several people reviewing this said, and they meant it as a compliment, that the audio sound was almost as good as a CD player, but that because of its nature, DVD/Universal players will never sound as good as CD players. I'm not saying this is gospal but because of this, I thought I would be better off trying out CD players first.

[nightflier]

Something else no one here has brought up: the Adcom DAC is decent, but for $250 used, there's a lot of other choices out there that would provide more depth, detail, and sounstage. I bought several DACs in that price range a while back and did some comparing: Adcom GDA-700, Aragon D2A, Arcam BB50, Parasound 1500, Theta DSPB-II. To my ears the Aragon was the best and so I kept it and sold the rest. Some of these came close, but I have to say that the Adcom wasn't as good. Again, that's just my opinion, and people have different tastes. It could also be how it fared with the rest of my equipment, which is another factor altogether.

In any case, I can say unequivocally that any $250 used outboard DAC (usually that means about $1200 new) will trounce any internal DAC on these $250 players. And if you're willing to spend more, a $1000 used DAC (about $3500 new), will shame any player in its price range as well.

[EdwardGein]

You probably are right. I never really heard of this stuff till someone recommended a Benchmark DAC that is around $1,000 new & as it is recent, its hard to get for a cheaper price used. The Adcom GDA-700 at one time went for $1,000 new & based on what was available in my budget range I bought it based on its pretty good reviews. If I hadn't gotten the PD-59 CD player, I would have kept it, as it definately improved the CD sound on my Harmon Kardon 31 DVD player. In regards to the Pioneer PD-59 though, I prefered the sound by itself then with connected to the Adcom. The analog cables I had on hand were a $50 pair interconnects, perhaps with much better cables, I'd have felt differently. The GDA-600 went for around $150 on Ebay & other DAc's went for as low as $100 or so. The more expensive ones went for $500 or more on Ebay.

[shokhead]

Can anyone list maybe the 3-4 most common Dacs used in say under 1K receivers and players from best to worst and maybe a couple of good ones we would be lucky to find in our stuff. Burr-Brown and Wolfson are the first ones i think of as in under 1K .

[topspeed]

Can anyone list maybe the 3-4 most common Dacs used in say under 1K receivers and players from best to worst and maybe a couple of good ones we would be lucky to find in our stuff. Burr-Brown and Wolfson are the first ones i think of as in under 1K .
Yamaha makes their own and, like most things Yammie, they're pretty darn good.
Sony used to make their own, but apparently are using BB now.
Crystal, Cirrus, NEC, and Analog Devices come to mind.

No ranking is possible as it's all personal choice.