Mike, that is a lot to think about. It would kind of stink if we didn't have something or other to fret over. Wow! is right. Decisions.....

gererick May 23, 2006 23:38

Rick, i did read Herve's impedence article in Stereophile. although the math pretty much just goes over my head it is not hard to follow his logic. i find it interesting to read him theorize about the ideal approach to interconnects and then sit back and listen to it's implimentation thru his gear.

i wonder how long it will take the rest of the HiFi world to catch up with his approach?

i did get a detailed response from Herve regarding using a second 8 meter set of BNC cables. he has not specifically tried that but thinks it theoretically could be better. he did tell me about a built-in feature of the dart pre that would improve things. there are three BNC outputs per channel and the dart pre; A, B, and C.....which allow for tri-amping. i'll let Herve explain;

***************

Then you could also use the preamp optional built-in filters. These filters will help reducing intermodulation between bass and highs. If you want to use the filters, you will have to use outputs B and C (B for the bass, C for the highs in bi-amp mode; when tri-amping we use outputs A, B, and C).
Frequency filters are set at 628 Hz and 6.28kHz, meaning the following:
Output B will deliver from nearly DC to 6.3 kHz for bass output, reducing high frequency intermodulation.
Output C will deliver from 628 Hz to dolphin-ear frequencies, avoiding bass intermodulation.
These frequencies were chosen not to interact with existing speaker crossover, provided your "high side" crossover start above 1 kHz or so.

Implementing these filters imply some soldering/unsoldering pads, like for the phono settings.

*******************

all i can say is WOW! talk about optimizing a system. i need to check on the crossover for my mid-range driver (Von Schweikert does not publish their crossover frequencies) to see whether i can use the filter on output C for my mid-tweeter.

it actually seems to get better all the time.

mikelavigne May 19, 2006 13:49

Jhightower, hello. thanks for the kind words. and you're wrong; your stuff makes music fun just like mine.

actually, i never owned any BAT gear but i have had a few different pieces of BAT gear in my system over the years; VK-50SE, VK-60 Mono's, VK-60SE, VK75SE, VK-P10SE and at one point the VK-150SE's. back prior to my initial contact with Tenor OTL's i did consider the 150's.

a few years back we briefly discussed the Rowland 112 (which i was selling at that time) as you were considering a move to Rowland.

nice system, by the way.

mikelavigne May 19, 2006 13:29

Hey Mike, long time. I think you owned some BAT 150SE mono's at one point. And knew a guy named russ, with those pipes (voice ability).

System looks cool. I am running Theta Gen VIII and Accuphase with JM Labs and Aerial Acoustics subs (yes, two).

Fun stuff, but nothing like what you have.

Keep the faith, and keep it fun.

jhightower May 19, 2006 02:00

Mike, thanks. Herve discusses it in the Audiophile Technical Manual, for which there is a link on DarTZeel's site under "Download". Page 16, 17, 18. Best, Rick

gererick May 16, 2006 14:10

Mike,

Really love your system.... top to bottom, just stellar.

Can you post a review of your VR9s? I heard the VR4jr but was not particularly impressed... but would love to read your take on the 9s. I havent heard much above the VR4jr in the VR lineup.

Though I've heard speakers all the way to the Wilson Maxx2 driven by Halcro DM68 monoblocks.

Thanks in advance.

Joey

joey_v May 16, 2006 06:33

Rick, i have not read the above article and am presently at work so i can't look it up for myself (i have every Stereophile since Nov 1994).

i did go to the darTZeel web site and looked up Wes Philip's review of the dart amp. in that review Wes refers to Herve's impedence article as being in the November 2001 Stereophile, pages 59 to 69.

tonight i'll read it myself.

mikelavigne May 15, 2006 18:36

Thanks, Mike. I'd like to read the article. I searched Stereophile's site using Herve's first and than last name, and was not successful. If someone can let me know the issue, I probably still have it. Thanks again. Rick

gererick May 15, 2006 13:44

Rick, about 5 or 6 years ago Herve wrote an article for Stereophile about the significance of impedance on audio. the concepts are beyond me but he is clearly onto something with the design of his amp and pre in regards to enabling them to take advantage of these cables. as it has been explained to me; 50ohm cables would only benefit gear that has been specifically designed for it on both ends.

i even investigated whether the EMM Labs gear could also use this cable; i was told until/unless the EMM Labs gear was designed to take full advantage of the 50 ohm spec it would not work to full advantage.

i hope i answered your question.

mikelavigne May 15, 2006 13:24

At that price, the DarTzeel interconnects must be a 'breakthrough' product. I'd like to learn more about them - what is the best way to inquire? Generally, I'd like to learn more about the applicability of these interconnects when not used with Dart amplification. My system does not have BNC connections. Even if my system did, it might not be 50 ohm. I am having a pre-amp built with RCA outs; I wonder whether I should request BNC outs, but then my amps have only RCA in. That could be modified as well, I suppose. etc., etc. Thanks. Rick

gererick May 14, 2006 23:30

Rick, the dart amp has one set of inputs for each channel; BNC (zeel), RCA and XLR (for version 'B'). there is also a three-position toggel for setting proper impedence for each input.

when i use the BNC (zeel) output from the dart pre (there are three BNC outputs from the dart pre as well as RCA and XLR) into the BNC input on the amp; i also use a BNC 'T' connector and a short jumper to the other channel (since i vertically bi-amp).

i could run a separate 8 meter BNC set from the dart pre for my other channel instead.

until your question here i never considered a second BNC cable from the dart pre to the other channel on my amp. i may e-mail Herve and ask him if that might give a performance advantage. i wonder if he has tried that.

mikelavigne May 14, 2006 16:20

Mike, Aaron, thanks. The Dart web site does not appear to have info on their interconnects. Also, there is a photo of the back of the pre-amp (one can see the 50 ohm BNC outs), but not the amp. If you use the BNC out of the pre-amp, what is the connection into the back of the Dart amp? Best, Rick

gererick May 14, 2006 15:34

French Fries; btw, i was out of town for a few days.

i am currently setting my crossover on the subwoofer of the VR9's at about 10:30 on the dial.....which is an increase of about 20 degree over where it was. i have also increased my subwoofer gain about 20 degrees (about 30 degrees beyond the 'dot'). i have also reduced my mid-tweeter gain from #3 back to #5 (looking from the rear of the speaker this is the dial on the right side below the upper speaker terminals).

it sounds like heaven. i will be descibing heaven more soon.

mikelavigne May 13, 2006 20:11

thanks Aaron, that sounds about right. i try to stay away from technical explainations so i don't hurt myself too much.

mikelavigne May 13, 2006 16:05

Rick, as i have not specifically compared the 8 meter BNC 'zeel' cables to shorter identical cables i can't tell you whether a shorter one would sound better. i did compare the 8 meter (about 25 feet) to identical 'zeel' cables 50 feet long and they sound exactly the same to my ears.

Herve Delatraz of darTZeel comments that due to his design approach that 'ANY' length up to one kilometer should sound exactly the same as any other length. please read his website for the scientific justification.

i did compare Herve's 'zeel' cables to some cheap versions and prefer Herve's. another dart pre owner has recently mentioned to me that he prefrred some other BNC cables to Herve's but i have not heard that for myself.

bottom line for me; from my listening i am COMPLETELY satisfied with the performance of Herve's cables and have no plans to change. similarly to my Placette RVC which i used for 4 years; even though it was cheap and looked very out-of-place in my system it was better than anything else i tried until the dart pre came along.

as always; i am open to my system sounding better if i hear something better.

mikelavigne May 13, 2006 15:28

Rick,

I am sure Mike will give you a better/more technical answer to this question than I could hope to but it is my understanding that the DartZeel components provide the option of using a special 50 ohm BNC connection, kind of like the fibre optic cable that carries communications signals over immense distances. I suspect that because of the very low impedance of the cable/interface the quality and length of the cable is a non-issue. The Dartzeel gear also provides normal single ended RCA and balanced XLR preamp-to-amp connectors to mate with the widest range of gear. In any event, it is often better to use longer interconnects of any type and shorter speaker cables when locating the bulk of your equipment away from the speakers.

All the best,
Aaron

drajreynolds May 13, 2006 04:10

Hello Mike,

I am not sure if you've already responded to someone's query, but how do you feel about your 8 meter interconnects versus shorter interconnects. Do you feel you're not giving up much? Also, the price you indicate for the Zeel interconnect is $1,900, which is out of proportion to everything else you have. And that is an important connection (pre-amp to amp, though all of the connections are obviously important). Is that price right? Are these interconnects that good?

Thanks.

Rick

gererick May 12, 2006 18:56

in my discussions with transparent audio's representatives they do offer some scientific explainations (resistance, conductance, impedence, etc.) in addition, they admit that carbon fiber was part of an experiment in resonance control, and they do not have the test equipment per se, but in listening tests, it appears to work significantly better than acrylics or metals in isolating the network components.
they admit the prices are obscene, but insist that the amount of work involved in putting the whole cable together is considerable. i myself have Reference-MM which is one step below opus. it's very expensive too! but it's not just wire- it's a component. so much so that anyone out there with a pair of eggleston andra's, or an equivalent quality speaker, might want to at least think about this wire. in my system the andra's produced DEEP, clean bass that brought organ recordings to life, and midrange clarity and a 3-D stage that i didn't think the speaker was even capable of.
in the end, if you have the money stashed away somewhere and you are a crazy musicphile, you're in for a real treat.

french_fries May 12, 2006 14:16

P.S. I might also add that just because Mike can't explain how the cables work or why they are so expensive does not mean the maufacturer will not or can not since I have not contacted them.

gregadd May 12, 2006 11:27

Less my silence be confused as an acquiesance in Mikes philosophy let me say that I do not agree. Price is relevant. A manufacturer should be able to explain how his product works. The more expensive the product the more he should be required to justify that cost
Obviously that it is not a requirement for others. I am however not prepared to dismiss a product merely because it is obscenely expensive without explanation. If I were I would not own a Koetsu.

gregadd May 12, 2006 11:22

Fred; fully agree. while high prices seems to demand justification it does miss the point that a product either performs or does not perform. if it performs then it becomes a decision of justification which is personal.

i do understand Greg's perspective......particularly for those that are techies; understanding the cause and effect is a valauable part of the hobby for many and their path to satisfaction or even the DIY approach. totally valid perspective.....just not one i share.

mikelavigne May 11, 2006 17:16

Ray, thanks for your comments.

Greg, i have considered writing a review on the Opus but might wait until i upgrade my Valhalla interconnects to Opus (a matter of budget and spousal consent of same).

i think a VR9SE or darTZeel pre review is more likely......a matter of finding the time.

mikelavigne May 11, 2006 17:10

A friend has recently been comparing various brands of audiophile grade connectors, both the male 3 prong connectors which go unto the wall and various IEC connectors. He recently tried the top of the line Oyade connectors which are $400 retail for the pair and the bodies of which are formed from carbon fiber. He comparewd these against the Oyade connectors immediately below them which are $220 and which appear to be exactly the same sans the carbon fiber body. The more expensive plug sounded significantly better, but is outrageously expensive, considering what you can buy connectors for at a hardware store. The point of this story and its relevance to Mike's comments about OPUS is the price which a manufacturer charges and the technology which he uses is immaterial. It either sounds good or it doesn't. It either works in your system to bring it closer to achieving what you seek or it does not. The rest is strictly an economic decision which each of us must make for themselves based on our priorities. In the case of OPUS, I do know that the carbon fiber enclosues for the networks are custom made in very small quantities. Based on Oyade plugs, I have to assume that these are not cheap. Likewise the build quality and quality of parts used is excellent and the time time required to custom tune each cable is costly. But again, this is not the point. The sound in your system is the point!

fcrowder May 11, 2006 13:51

I mean Positive Feedback Online.

gregadd May 11, 2006 13:01

Maybe you can review them for POS?

gregadd May 11, 2006 04:33