Opinions on Kimber AGDL (1 Viewer)

[Ron Reda]

Curious as to what people think of the Kimber AGDL digital cable. I've read plenty of good things online, but I want to hear what people here have to say. It will be used to connect a DAC to a CD player. Also, any alternatives to this cable would be appreciated.

 

[RobertR]

There's no good reason to think it will sound any better or any worse than any other "digital cable".

 

[Chu Gai]

FWIW, here are the requirements for digital signal transfer.

From International Electrotechnical Commission standard IEC 958 1989-03,
pp 37, 39, we read:

5. Electrical requirements
. . .
5.3 Unbalanced line (two-wire transmission)
5.3.1 Cable construction
The interconnecting cable shall be screened and have a characteristic impedance of 75 ohm +-5% (transmission length > 10 m) or 75 ohm +-25% (length < 10 m) at the data transmission rate used.
...
5.3.2 Line driver characteristics
5.3.2.1 Output impedance
The line driver shall have an unbalanced output with an internal impedance of 75 ohm +-20% ...
...
5.3.3 Line receiver characteristics
The receiver shall present a substantially resistive impedance of 75 ohm +- 5% to the interconnecting cable ...

I'd say whatever meets those requirements should do just fine.

 

[Phil A]

The signal traveling over a digital (coax) cable is not transmitted as 1s and 0s. So anything that can cause problems with an analog signal can also cause problems over a digital cable. I've done DBTs with digital cables several times, including participating with others who believe nothing will change the sound as long as the cable meets specs. Differences were in fact noted by everyone (with sometime humorous explanations for those who are spec oriented - I even let them borrow the cables to have them tested for specs which they all met).

That being said, differences have been noted with the same cables on another system to a much smaller degree and in some cases the differences were almost nonexistent. So it is highly dependent on what you use it with. Digital cables are likely to have a smaller impact bang for the buck vs. other things such as good isolation of the transport. It could be anything from homemade stuff or stuff to Bright Star Audio's Isonode feet (www.brightstaraudio.com $12.50 for set of 4) ) to LAT International's - http://www.latinternational.com/inde.../prod-312.html ($39 for set of 4) to Gingko Audio's (www.gingkoaudio.com) Cloud 10 Isolation Platform ($300).

I've found from playing with all sorts of cables (incl. a $900 digital cable), that those made with Belden 1506a will get one pretty much most of performance of anything silly expensive. I believe they sell it at various places such as: http://www.diycable.com/main/product...roducts_id=135 (which mates nicely with teh Canare connectors and costs $65 and has a trial period, which I would recommned be used with any such product).

So it is dependent on your budget and how much of a fanatic you might be for that last few % of performance which to me would not be worth it for most people, expecially given the cost to performance ratio.

 

[Phil A]

As a side note you will get many different opinions on things. I am one to objectively try things vs. spouting a theory on why something might or might not make a difference. I've found many times I expected differences when there were none and vice versa so I am not much of a theory person.

Bryston's current newsletter, http://www.bryston.ca/newsletters/82_files/vol8is2.html

has some of the scientific stuff on cables and from what they indicated they will comment more in future newsletters. The last newsletter addressed digital amps. So they cover a whole spectrum of things. I love their equipment (have 14BSST and 6BSST amps and an SP 1.7 pre/pro) but have tried their balanced cables (against expensive store brands like a $1.1k balanced pair) and in my opinion they suck big time. A friend of mine had the same experience with them and unfortunately bought the $1.1k balanced cable pair to go from his SP 1.7 left and right channel to his left and right channel of his 9BSST amp (and not cheap but cheaper cables from the same brand) on the other channels. He then one day borrowed some of the cables I make after seeing and hearing my system and the expensive cables were sold rather quickly, including $2k speaker wire for the left and right channel.

So I am a fan of cables can make a nice difference but don't go overboard and only buy something that either has an in-home trial period or that you can listen to extensively on a system substantially similar or the same as your own. Too many people get sucked in by a combination of reviews (the reviewer's get accomodation sales and the publication gets ad revenue) and sales people (who naturally make commissions) and so it is hard to get an objective opinion many times. I've actually been in someone's house who had between $30k-$40k of cabling on is 2-channel system (using the same speakers as I have) and while it sounded good, I am not so that replacing it with my cables would make it sound any lessor and I'm sure the person's sales person was very happy to make the sale.

 

[Chu Gai]

I enjoyed (really I did!) reading your post Phil. If you can recall, what were the cables you tested and if you wouldn't mind sharing the components. Also what kind of results did you obtain?

 

[Phil A]

Chu, my old set-up included a Proceed AVP pre-amp and Proceed electronics along with an equipment rack that had easy access for the cable changer, who never participated in the test, and was also extremely difficult for the participants to see what was being changed and what the cables looked like. My new set-up (over the past yr. and a half is not really conducive to such test both by ltd. inputs and difficulty getting to the back of things)

My speakers (back then and now) are Thiel 7.2s crossover to 2 Rel Storm IIIs subs at 22HZ. The amp powering the speakers back then (now 14BSST) was a Proceed HPA and I used back then a Proceed PMDT (Modular Digital Transport) that was a DVD/CD transport (not player, no analog outs, digital ones - balanced, toslink RCA coax and BNC coax). The AVP pre/pro also made it very easy to define more than one of its inputs as coming from the PMDT so it was very easy to do A/B comparisons. Back then I was using speaker wire was a small co. that a friend of mine owns, Empprical Design. I now have my own speaker cable on it.

The balanced digital cable used was a few yr. old Transparent Digital Reference ($900 - still have it but not using it as I sold the PMDT). For single ended stuff, I had a variety of stuff from Empirical Design, Monster, MIT, Audioquest, Jenving (a Swedish manuf.) and perhaps one or two others.

In every instance the test was done, everyone heard differences at least in some of the cables. There are those that were not as unique. The Transparent balanced came in 1st just about every time (it should for what it cost). I would not describle all the differences as earth shattering but there was definite differnces in the timbre of voices and the soundstaging. I found that some of the cheaper cables performed remarkably well at their price points as compared to more expensive ones. I had several engineer types who came out with some amusing theories as to why they sounded different. I lent a couple of them the cables to test and they all met spec. Most often they implied that the differences were probably due to some small defects in the preamp inputs, however, the person not participating had done enough swaps that that was effectively eliminated (and it was quite amusing to try to see them scientifically wiggle out of it).

I also realize that as a transport alone, I was dealing with a piece, the PMDT, which w/o the progressive scan option was $6k and on par with Levinson's much more expensive transport. Out of curiosity, after a couple of these tests, I tried stuff on my bedroom system with many of the same cables (Sony 444ES Receiver, Thiel SCS2 speakers, Pioneer Elite DV-47A universal player and a Sony 9000ES just prior to that, cheaper speaker wire) and found (in a more conventional unscientific manner) the results were not as dramatic as far as differences. I tried the same stuff in other less scientific tests on other peoples systems and then hooked up my old B&W P6s to stuff I had laying around at the time which was a Rotel Pre/Pro Tuner, a Bryston 4BST amp, Bryston power pac monoblocks and a spare LD player (Pioneer) and DVD player (Panasonic) for a while. I started reading stuff and realized that technical stuff is not my cup of tea so I just started ordering lots of different things to make digital cables, analog cables, video cables, speaker wire, power cords. My loft upstairs looked liked a mad scientists lab.

So after playing with lots of stuff and listening to certain things over and over (almost can't listen to some of it today), test were again conducted a couple of times. The Belden 1506a was used as a digital cable this time and came pretty close to the $900 Transparent (maybe 97% of the performance) in many areas. I had the opportunity to borrow and try very expensive stuff (a friend worked at a high end shop on a regular basis and now just fills in sporadically) and got to the point of being satisfied that what I narrowed my searches down to was something good in a variety of systems. I sold off most of the stuff from the mad scientist's lab and now I just enjoy software on my system (have a Modwright - www.modwright.com - Absolute Truth Mod on my Sony XA-777ES has a CD/SACD source now).

I helped my friend who worked at the high end store deliver things over a 5 yr. period as well and got to see and try lots of other things. One day we delivered a system (I noted in an early post) to someone a half mile from my house who I ultimately became friendly with. He has Thiel 2.4s, a Bryston SP 1.7 pre-pro, a Bryston 9BSST amp and a Linn Ikemi CD player. One day he called as he borrowed a Marantz 8260 (CD/SACD) to see how he would like it (he is probably more of 2-channel guy than me even though he as well has his system as part of a home theater) and wanted to borrow 3 identical pairs of cables for multi-channel. The only thing I had was stuff so I removed them from my system and let him borrow them. He had all expensive stuff as far as cabling goes as I noted. Well, unknown to me he decided to A/B them against his expensive store bought stuff. I came back over his house and the Linn Ikemi has 2 sets of analog outputs. On one set he had his expensive $650 list interconnects and on the other set he had mine, which was unknown to me. He had played them for his wife who claims to hear nothing and was blown away, also not known to me. So he played them for me, doing an A/B and I noted right away from hearing what he was playing. You would not believe the difference on just one of RCA cables going from the CD player to the pre-amp. So expensive does not mean good to me automatically.

 

[RobertR]

I'd be interested in a complete description of the methodology involved. Were the listeners in the room at all when the cables were changed? Did the the cable swapper have any contact with the listeners? How was the sequence of cable swapping determined? Was it randomly selected, or did the listeners know that a change had been made (even if they didn't know which cable was used)?

 

[Phil A]

Robert, the postion of the rack used and the equipment made it difficult to see anyway, but we left the room anyway. The set-up I formerly had was good for test for analog and digital interconnects. I tried power cords and speaker wire but it was too obvious to see the wires and involved continuous swapping. With 4 digital outputs on my transport, it was not a difficult thing to hook it up 2 inputs defined on the pre-amp, although we usually just did an A/B. The cable swapper had no contact other than being in the room with the listeners. There were even duplicates of some cables. The cable swapper did all the determinations. It was fairly obvious by the switching one could hear when a change was a button was hit on the remote, as there was nothing much that could be done there, however, as noted, in some cases the switch was to the same cable or even hitting the same input so all that could be ascertained was that a source was selected on the remote, not necessarily a different one or perhaps even a different one but the same cable. I did the test 4 different times. Twice after I started making my own stuff and twice before. There certainly were differences noted by everyone. I did not partipate after the 1st test as I took more of an inactive roll trying to make sure there were no discernable volume differences in the cables used. I did the swapping in the last test. I also took one of my digital cables over to a mini-meet once and while there was only a couple of people there, they had no idea which cable I put where and there were differences they both recognized. All the tests were done with music not movies. I think it would be much more difficult to do it with movies with all the channels playing. I have the same difficulty with multi-channel music.

As I noted, I did less scientific type tests on other equipment and not always had the same level of differences noted. I've also taken tests with my stuff and others in the store after hours with my friend hooking the cables up and switching so I had no idea other than be listening as to what was selected. I would not equate what I did to the most stringent controls possible in a scientific laboratory sense as the goal was to work with the best conditions I had to determine differences. For example, I made sure there was as little noise from heating/A/C but I did not measure the voltage from the wall or other aspects of the power coming into the house or room, nor did I measure atmospheric conditions in the room at the time of the test. I had originally bought some expensive cables and wanted some skeptics to prove I belonged in a straight jacket so I could ignore doing more to the system. It ended up evolving into making stuff and after driving myself a bit crazy, I'm perfectly happy with what I now use.

When I want to test something now, I make something and give it to friends to evaluate for me (my set-up is longer that conducive to swapping and I have a couple of friends that are probably much more fanatical than I am). One just had me make cables for a used Yamaha tuner and a satellite receiver. I think he had AR stuff on them (which he liked better than an entry level high end brand which was about 4 times the cost). I thought he was a little over the edge (but he is making some bass traps for me to play with). I still use prototypes and cheaper stuff on my non-critical pieces. I went over there to drop-off my RTA so he could use it in conjunction with the bass trap project and he remarked to me that the cables on the tuner he had put on yesterday made his tuner sound more CD-like.

I encourage everyone to listen for themselves. I've been in stores and seen sales people almost snicker when they have somone in there who had last yrs. cable model and wants to hear what the new one will sound like. I've had the same observation when the same manuf. came out with a new solid state amp of substantially the same power and circuitry and people just want it since it is the latest and greatest. People overlook the most important component of all, the room. I've help set-up a 2-channel system with $85k retail speakers (bought used at around $27k and replacing a $12k pair at retail). The room was just untreated and not right for the $85k speakers. It was not my money or business. When we left my friend who worked at the store said the guy should just sell it and buy the same speakers I have and pocket the difference and it would work a lot better in the room. Not every system is as sensitive to changes as others. I've been involved in 200+ installs of some very expensive stuff in terms of equipment and cabling. I went along for the experience and to have some beers afterwards with my friend. I was more than happy to be able to learn things while having someone else be the guinea pig in terms of cost.

 

[Chu Gai]

First let me begin by thanking you for a very thought out reply and I appreciate the effort that you expended. I've actually heard of this happening Phil. Allow me to expand on some of the details which may have some bearing on what you experienced.

Some sources that are out there, and it tends towards the high end, are designed (knowingly or unknowingly...I've no idea) such that they have some problems driving a cable when the capacitance gets to some point. It's my understanding that what this does is result in signals with variable rise times. As the capacitance decreases, either through cable design or through a shortening of the cable, usually the problem goes away. I say usually because I would think it entirely possible that only the most trivial of capacitances would not tax the ability of that particular source. So, despite that the source might be highly regarded and in that context it's often given the term revealing, it's basically defective. That doesn't mean it's not capable of competent performance, it's just that it hasn't been designed robustly. I've heard various terms applied to this...poor phase margin...inadequate current capability and so on.
Moving on to the 'destination' I've heard that there are some units that contain DACs, usually of the esoteric or specially designed variety, that have problems when the rise time is not sufficiently sharp. In that context, one must consider the statement DACs as meaning both the DAC itself and related circuitry. Again this is less of a problem with mid-fi equipment I presume because the testing protocols are more involved and easily done due to greater R&D resources. The manifestation is such that jitter goes through the roof. Not from picoseconds to nanoseconds, but to even milliseconds. IOW audible distortion, not necessarily pleasing, becomes painfully obvious.
When one looks at the two scenarios, it's entirely reasonable to expect that two different cables, meeting the specs I outlined above, would behave differently if their capacitances were different.
One interpretation of course is that cables make a difference. Another interpretation, the more correct one in my estimation, is that some piece of equipment has a problem that can only be rectified by careful choice of cable.
When one peruses the literature regarding vendors of cables, occasionally one will see the capacitance listed. Further one will find an inverse relationship with capacitance and price. One of the primary reasons that teflon is enamored by the audiophile crowd is for the simple reason that as a dielectric, it offers slightly lower capacitance than polyethylene. Foaming also decreased the capacitance. I'm sure you've seen the audio interconnects that are basically wires suspended, but not in contact with, the dielectric. That's done to further reduce capacitance as air is the best dielectric and will lead to the lowest capacitances.
How this applies in your scenario, I really don't know. My educated guess would be that something along the lines of what I mentioned above applies. It would've been fun to be there though. You seem like a man who wouldn't skimp on the beer, right?

Edited after the fact...
I reread your Bryston link. I think that they're suggesting much the same as I stated above. They're thinking, I take it, that they want to design an interconnect that interfaces well with all equipment, including poorly designed or defective ones.

 

[RobertR]

Thanks for your reply, Phil. I do see some problems with the way the test was implemented that, IMO, keep it from being a properly implemented DBT.

First, the cable swapper should have no contact at all with the listeners. He should connect the cables, leave the room without any contact with the listeners, and remain so while the listening is done. Otherwise, the test is really single blind, not double blind.

Secondly, it sounds like the actual switching was done using two separate inputs. Without knowing more about the design and setup, I wonder if all the parameters of each input are identical. A better procedure would have been to have the cable swapper use the same input, randomly selecting what cable to connect to it, then have him leave the room, and repeat the procedure. That way, it's guaranteed that the only variable that changes is the cable, and that it would be impossible to know anything about the cable other than the sound.

 

[Chu Gai]

Valid points Robert but I do tip my hat to Phil who obviously went to far greater lengths than many do or can. How were the levels checked Phil? Overall I'd say you must've enjoyed helping your friend and I quite agree speakers/room.

 

[Phil A]

Chu, I definitely don't skimp on beer :b

Robert, the preamp had multiple digital inputs that were capable of being assigned to one device. The digital inputs are the same and even if there was some small difference, there was enough swapping that all the cables were on the inputs used multiple times. There was no possibility that there was difference in the inputs based on the tests. Due to limitations in room and the ability to control the switching and have people be in the sweet spot dictated the need for the manner in which the tests were conducted. As I noted, I did not measure items like voltage from the wall so there was no way to equate this to the absolute equivalent of a lab type environment. It started out as just an experiment to test some of the store bought stuff I had and turned into something else.

My intent was to just tell the original poster to listen and listen in a manner that does not involve putting out cash with no means of returning it w/o a money back possibility. I noted I don't care much for analysis and I am sure that some of the differences were likely due to the equipment involved as I did not necessarily notice the same exact things with the same cables elsewhere.

My current set-up does not allow for such easy tests and is a pain to get to. I brought over a multi-channel cable to my friend the other day so he could listen in stereo only and give me his thoughts vs. the separate stereo analog interconnects I made. I have another friend who hates almost everything and when I get a new piece, I generally lend it to him for a few weeks so he goes over it and tells me his thoughts. Much like reading a review and knowing the reviewer's system and likes and dislikes I am very content to get my feedback in that manner now. I got a free Philips DVD recorder (I don't record much, copied a couple of home video tapes onto DVD) with my Philips VISA points and it stayed at my friend's place for month. I have a Marantz 7300 OSE receiver I traded excess equipment for so I'll have something when I finish the basement over the next several months. It is temporarily hooked-up and it will as well go over to my friend so he can pick it apart.

Many times people ask questions when I think it is better for them to go listen with their own ears and reach their own conclusions. I've worked several days in the high end shop over the years as a favor for my friend. People will walk in and have their preferences (e.g. how can anyone buy that when this is the same price and then you get someone an hour later that tells you the same thing in reverse) and have bought expensive stuff that in my opinion sounds absolutely horrible at its price point compared to other stuff available in the same room. I've helped deliver expensive equipment that I liked that absolutely sounded horrible in the room and were obviously not a good choice for that room (almost 3 whole glass walls, stone fireplace, hardwood floors).


Everyone has tastes and preferences, their own budget, monetary priorites, etc. I am more than happy to enjoy my hardware and software and don't really mind whethere someone thinks Bose is wonderful or that wire is wire. I think we're still a few years off from being able to build a bionic ear where perhaps we will learn a bit more about why and how people hear things. People get too worked up about stuff that is a hobby and should be fun. Go over to Audio Asylum and look at the DVD-A vs. SACD posts. Some of them are quite funny, and are almost competition to the bizarre entertainment of watching a Jerry Springer show.

 

[Brian OK]

Ron,

Aren't you glad you asked for Kimber AGDL feedback ? ;*)

So many queries like this go down the wrong road, far away from the posters sincere intention. Such as it is here.

I used the AGDL for a short time and then sold it off. Very forward cable with tons of detail and outstanding bass. IME, it did not mate well with my rather bright system at the time (Yamaha and Paradigm). I also experienced audio dropouts with the ADGL. It is a very thin cable in terms of construction, but it is a little dynamo at the same time.
If silver is your cup of tea, then the AGDL is definately worth a listen.

For me, I ended up with an AZen Silver Photon, but also enjoyed the Harmonic Tech Copper digital as well along the way. Agon used is your best source for an AGDL, but you know that already.
Good Luck,

BOK

 

[Joel()Les]

Interesting discussion. I know that I could not swap the cables fast enough to detect minor variations in sound.

Phil:
1) Did you test an optical cable as part of your experiments?

2) How does the Belden 1506a compare to the 1505a (RG-59 type Brilliance Precision Video Coax)or Belden 1694 (RG-6 type Brilliance Precision Video Coax)?
Bluejeans offers reasonably priced cables with those options.

UPDATE:

Went to Belden's site. The 1506 is the Teflon version of the 1505. The 1506's nominal Inductance and capacitance measures are slightly lower than the 1505. The 1694 is lower resistance and its inductance and capaciatance are just below the 1505 but above 1506.
I gues the 1506 looks better but whether there is enough difference in a 1 meter cable between these, I sure don't know.

 

[Phil A]

Joel, I sure don't know whether there would be much of a difference on a particular system. I like the 1506 as it works very very with the Canare '4' size connector (the same that diycable uses) and once one has the tools it is not a horribly difficult cable to make. I actually gave a couple of (analog) cables to my friend down the street to test while I made him my good stuff (I like having other people do the testing - not a pain for me and I know he will give me an honest answer - not as much into the test stuff myself as I think I've wired myself out and am happy with what I have). He though it was decent as an analog cable, about in the same league as a $130 list pair of MITs I also lent to him. He said it was not close to my analog cable. I gave him one for his DVD player (he is pretty much an audiophile and does not have a great TV and a cheap JVC DVD player). I'm sure at the price points diycable or Blue Jeans are very good. The bad part about buying and making your own stuff is you need to buy it in bulk (I think I bought a 500 ft. spool of the 1506 which I've used to play with on various things) and need the right tools.

Yes, I did test an optical cable. The Jenving cable (www.jenving.se is a Swedish co.) I bought it from them before they had a US distributor and also bought a bunch of their termination trousers (kind of looks like trousers but it used to separate cable runs). I think the cable cost me around $90. I've found that for the most part coaxial sounds better on digital connections. This sounds pretty good though. It costs that much since the ends are precision machined over and over so they make a better connection. I'm actually using the cable on the optical digital out of my HDTV box. It has both an optical and coaxial ouptut and the coax goes to the main system and the optical into an optical to coax converter and then I run a digital cable thru the wall to my bedroom system on the other side so I can get digital TV sound (along the the 'S' video cable for the picture). Optical cables can be more fragile and also don't do as well being bent vs. a coax design. I can certainly live with them for less critical things like TV sound and it may not be that horrible for movies, although I would still use coax by choice.