Long XLR's: PAD Venustas versus Mogami

In case anyone missed it...I recently had a bad (relatively) experience with some new 1 meter Mogami Neglex/Neutrik terminated balanced cables...they were surprisingly unlistenable in my system (Kavent S33, Forte' Model 55), and this is after using Mogami for mic cables for many years. Go figure. I suppose I should have waited for a "break-in" period but it was just too unbearable even for that...replaced 'em with Audioquest Diamondbacks and they are so much better I just bought a second pair to connect my DAC to the balanced pream inputs.

06-07-11: Glai
According to the equation, I should be able to use cables of higher capacitance (Mogami) without audible roll off. In practise, the Mogami sounds quite rolled off. What other things do you think are at play there?

Don't know. I'd just put it in the category of cable effects that are technically unexplainable.

If you had an unbalanced interface, I would have speculated that perhaps the Mogami's excellent noise rejection capabilities might be introducing less low level background noise onto the signal than the cable(s) you are comparing to, at upper treble or lower ultrasonic frequencies. I've read a number of times that very low level high frequency noise can subjectively be perceived as increased "air" and ambience. But I doubt that that kind of effect would be at play in the case of a balanced interface.

Best regards,
-- Al

Al,

THanks for the insight.

Unlike the BAt preamp, the einstein has output imped. 100ohm and it also does not rise at bass freq. According to the equation, I should be able to use cables of higher capacitance (Mogami) without audible roll off. In practise, the Mogami sounds quite rolled off. What other things do you think are at play there?

06-07-11: Madfloyd
So capacitance is the main parameter to consider for longer runs (where the lower the better)?

Capacitance and shielding, although the significance of shielding is lessened if the interface is balanced.

Shielding will affect susceptibility to both noise pickup caused by rfi/emi, and ground loop-induced hum and noise. The likelihood of both of those things becoming an issue increases if the cable length is long. Some cable designs achieve increased shielding effectiveness at the expense of increased capacitance, so there may be a tradeoff that has to be considered.

As far as lower capacitance being better is concerned, what matters (if you want neutral behavior, as opposed to a softened upper treble) is that the capacitance has to be low in relation to the output impedance (at high frequencies) of the component driving the cable. Reducing capacitance beyond that point would be overkill.

That can be calculated. Determine the capacitance C of the total length of cable, based on its specs. Calculate its capacitive reactance Xc (the capacitive form of impedance, measured in ohms) at 20kHz, based on the formula

Xc = 1/(2 x pi x F x C)

where Xc is capacitive reactance in ohms, pi = 3.14, F is frequency in Hertz, and C is the capacitance of the total length of cable in farads (1 farad = 1 trillion pf). As long as Xc is much higher (say 5 or 10 times or more) than the output impedance at high frequencies of the component driving the cable, you are good to go, as far as capacitance is concerned.

All of this applies, btw, just to line-level analog interconnects. Speaker cables, phono cables, digital cables, etc. are a different story altogether.

Regards,
-- Al

So capacitance is the main parameter to consider for longer runs (where the lower the better)?

06-06-11: Glai
Oyaide is an interesting idea. PA 02 only has two connectors. Where does the ground goes in XLR, should I hook the ground to the shield?

Yes.

BTW, the Cable Company page for the PA-02 that I linked to earlier appears to have the description of a completely different cable, even though the title and photo at the top of the page are correct. Use the information at the Oyaide link I provided.

What is the specifications in cap, ind, on PA 02?

As indicated at the Oyaide site, the capacitance is 32pf/meter, which is very low.

Inductance is not directly indicated, but it can be calculated from the capacitance and the specified "characteristic impedance" of 120 ohms. Using the relation Z = square root(L/C), which is an approximation but an extremely close one in most relevant circumstances, the inductance works out to be 461 nanoHenries/meter, which is a reasonable number.

I'll add, though, that IMO inductance is an unimportant parameter for an analog interconnect. Under ordinary circumstances the impedance it represents at audible and even ultrasonic frequencies will be a completely negligible fraction of the input impedance of the component that is being driven, and therefore it will have no effect on the signal seen by that component.

Regards,
-- Al

I run 5 meter pair of purist dominus (updated) in XLR and also have mogami. My einstein preamp have very low output imped for tube preamp. The Dominus sounds a lot better than Mogami. Mogami sounds opague with closed in treble and lacked detail. I also compared the Venustas in 2 meter config and they are better than Mogami as well. I was hoping the Mogami would equal the purist so I can save some cash. this was not the case.

I recently have great results with Cardas bulk tonearm cable (shielded). This equal many of themuch more expensive tone arm cable I tried from MSRP 500 to 4000.

I am itching to bulid a 5 meter XLR version of the bulk tonearm cable to serve as interconnect as it seems to have low capacitance. ANyone sees any problems with this concept.

Almarg- Oyaide is an interesting idea. PA 02 only has two connectors. Where does the ground goes in XLR, should I hook the ground to the shield?

What is the specifications in cap, ind, on PA 02?

Thanks

Al, maybe I had it reversed?

Since when does your hearing deterioration obviate gear differences? Does soundstaging comprehension or perception of tonal subtlety change? No. Note how many pro engineers are over 50...or over 70...mastering geniuses like Bob Ludwig, etc. Some top end goes but that's pretty much it. I can hear gear differences and I've been playing loud guitar since 1967...some tinitus and some top end loss...and ghostly voices inside my head to keep me company.

06-03-11: Nsgarch
Al, my assumption (in the case of the AC's) is that the user keeps the two runs a reasonable (like 4" or more) distance apart.

Hi Neil,

That will reduce capacitance to extremely low levels, but will actually increase inductance from the already not particularly low value it has when the wires are twisted together.

See the numbers at the bottom of this page.

Best regards,
-- Al

Al, my assumption (in the case of the AC's) is that the user keeps the two runs a reasonable (like 4" or more) distance apart.

Neil, one small correction to your reflective and interesting post. Anti-Cables (both the speaker cables and the interconnects) do not by any means have low inductance. In fact their inductance is considerably higher than that of most audiophile-oriented cables.

That would make their speaker cables, btw, not a good choice for use with electrostatic speakers such as yours, unless perhaps cable length is short or a slight upper treble rolloff is wanted. The cable's impedance rise in the upper treble region, resulting from that inductance, would (except for short lengths) become significant in relation to the very low impedance electrostatics usually have at high frequencies, attenuating the upper treble at least slightly. With dynamic speakers such as the Vandersteens that Stringreen uses, that would be a non-issue in typical setups.

Regards,
-- Al

For those of you interested the speaker/floor interface, there are already many threads on the subject, this forum is about cables.

Stringreen, your remarks (about your experiences with the Anti-Cables) is a perfect illustration of why I think it's SO IMPORTANT for people to post their systems!!

Just imagine me reading your post at face value -- which is what we all do first, of course. But your post as presented is (probably) interchangable with a dozen others just like it, maybe even word for word! As such, it can not, and does not tell me anything useful with respect to my own audiophile life/understanding/experiences/equipment etc.

Why should I believe you actually tried all the "top line stuff" you mention? And what difference would it make anyway? And the remark about "no best cable"? Yeah, right! We've all been treated to THAT "unique and profound insight" a few hundred times! So what? A flair for the obvious? Not very helpful . . . .

BUT WAIT! This person has posted his SYSTEM! OK, maybe he's put his money where his mouth is (literally, this time!) Let's see . . . .

OK. Nice lineup of stuff. Cost a few bucks. Solid manufacturers with good performance track records. Appears to understand the notion of synergy between certain kinds and makes of components. Nothing megabuck, but everything is at a similar level of (very good) quality. Perhaps he's working from an overall 'vision' of a system he imagines he will create or refine as he goes along. He doesn't appear to have selected anything out of expedience; that is, no budget/midfi gear (from the Advisor or Crutch catalogs ;--) just to "fill out" the "lineup" ;--) He's frugal, but has the 'scratch' to try/buy something he believes worthwhile; (so he probably really DID audition those fancy cables ;--) still, he sees no reason to have the 'latest version' of most things. Willing to wait patiently until something he really wants comes up on the used market perhaps. Someone with an intelligent measured approach to creating a system.

Does he know a lot of "audio science"? Maybe; maybe not. A hard thing to evaluate by just looking at a person's system choices, and no further discussion with them. Do I believe his remarks about the Anti-Cable? Yes, I do! Specifically when he says how he loves them with HIS components. I can fully understand the authenticity of that remark, simply because I know from my own experience, that the "top line stuff" he mentions, if installed in his current system, would very likely NOT improve its performance over what he now enjoys using Anti-Cables. The AC's have VERY low inductance-and-capacitance, which IMO is sufficient to fully optimize the performance of the components and speakers he has right now. His whole system, as currently constituted, is in an almost perfect state of balance; with no component/element 'out-classing' any other. The "bad news" about such a situation, is that if he makes a significant upgrade, especially to amp or speakers, then every element in the system will have to be reconsidered one by one, and probably also improved, including all the cable paths. At that point, the Anti-Cables themselves will NOT have all the attributes necessary to support a more refined system -- they will only hold it back from performing its best.

Stringreen's is the kind of system I used to put together myself when I was (much ;--) younger. I really took a lot of pride in what I achieved, and should have quit right there and gone on to stamp collecting ;--)) But there's no end to sonic improvements; until one day you realize, as I have, that your system has improved while your hearing has deteriorated, and it's time to stop.
.

I have used the Adona platforms under my speakers. They are granite with a layer of MDF bonded to the granite. I used them granite side down and either set or spiked the speakers on the MDF side. They worked quite well.

I spiked my speakers the other night to see what I was missing. I first tried it with the lowest setting but it produced way too much bass. Wilson provides spacers for this type of situation and so my next attempt was with both spacers (equaling the height of the casters).

With this I didn't hear much difference from the casters, but I did *feel* the bass more (concrete floor for what it's worth).

My experience with coupling versus de-coupling varies based on the room/floor/subfloor and speakers.

When I had my listening room in the basement with a concrete (carpeted) floor, coupling worked very well.

My current room incorporates a floating wood floor system and de-coupling works better in this room. I run Wilson W/P speakers mostly, but others as well. Though I am contemplating the use of a largish marble/stone slab for its mass/weight and placing the speakers on this. Have others tried this approach and what has their experiences been?

Boston Audio makes graphite/steel tune blocks to be used under spiked speakers. Anyone tried this?

Regarding the speaker spike suggestion...After messing around with spikes for many years I recently put Vibrapods under my smallish floorstanding speakers (wood floor). Sounds great...and I see more speaker manufacturers (and tweek designers) using some form of speaker "de-coupling" technology (like the Sonus Faber Amati Futura). Is this a paradigm shift?

Next time "refuse that" and you won't have to appologize.
I have another Purist cable that once was full and now empty. With everything else remaining the same, the sound is worse in every respect.
Also, some people on this forum appear to be unable to actually hear anything.

As I have posted many times beore...there is no "best" cable. All cables sound different hooked up with different components. I just love Anti=Cables with MY components, after trying much of the top line stuff from PAD, Nordost, Kimber, Cardas, Audioquest, MIT, etc., etc., I lucked out because AntiCables are inexpensive too.

New windshield wipers really make my car drive better. I recently took my car in for new windshield wipers and it drives so much better now. They also put new tires on when they did that and I think they may have done something to the engine too. Windshield wipers are great, they just need to be replaced every couple of years or so.

Sorry Inna, I couldn't refuse that ;-)

Oh. I'm out of this discussion.

I can confirm that fluid in PAD cables makes a difference. I had Maximus interconnect that was 2/3 empty, sent it to Purist, got it back refilled, and now it sounds better. They cleaned the connectors too, and possibly did something else as well - I don't know.
Purist cables are great, just need some care every ten years or so.

Hi all; and wishing you a reflective Memorial Day. This is no place for politics, but I would encourage everyone to watch Adm. Mullen's comments this morning, essentially the same remarks, on all three networks!

First, I want to make a general comment about something so CLEARLY illustrated in this thread: and that is for most of these forums/discussions/threads to be a source of MEANINGFUL information for both the original poster AND the respondents, it is SO IMPORTANT I think, for AudiogoNers to post their systems -- AND, to keep them UP TO DATE!! For without ACCURATE contextual information, most of these forum discussions amount to a pointless waste of time and thought -- in fact I will usually pass on some otherwise interesting topic, because I see that the OP has not provided a link to a 'System Page'.

Everyone here (so far ;--) has a System page and that's great (even though one of them apparently needs a little updating? ;--))

to John (Frech): You have the good fortune to have climbed all the way to the top of 'PAD Mountain', a view I will never get to see in this life, unfortunately. I remember that John and I started out with all Venustas systems -- and it should say something to the rest of you about PAD cable, that John always seemed to do his (system wide) cable upgrades using PAD products, even though it would have been so easy (system wide) for him to switch manufacturers; but he didn't!

Dan and John and Floyd use speakers with drivers that produce strong reactive loads; so it's important to use cables that don't add induction. In fact, the easiest way to eliminate BOTH capacitance AND induction is to separate the cable runs, a la Virtual Dynamics, PAD Provectus, and (don't laugh!) Speltz Anti-Cables, to name just three. As for clean-bass-with-tube amps, keep speaker cable length under 8 feet -- the shorter the better -- and use the biggest wire size available in your favorite make/model -- but at least 10 AWG, 9 AWG, or even larger depending on speaker power handling capacity and amp power. Also, if anyone wants to take a second and look up the specs ;--) you will see that Mogami 3104 in quad config. (their 'biggest' speaker cable) has a capacitance of 38.7 pF per ft. and a maximum conductor size of only 12 AWG. Compare just THOSE TWO parameters to Venustas: around 18 pF per foot (11 for Provectus) and 9 AWG and you'll understand why Mogami could sound glary with many speakers; and with just 12 AWG of conductor 'meat' in the Mogamis, good luck getting much energy transfer (i.e. -- bass!) which is going make your system sound (relatively) even more treble-ey! Mogami is NOT a neutral sounding cable, and its reputation goes back to the old days when power was low and speakers very efficient. Not so today.

Really any power cord with minimum 9 AWG conductors will provide good energy transfer for amps, power re-processors/regenerators, and for (I still don't know why ;--) dacs and digital stuff in general. Shielding is nice, but really only mandatory on digital equipment. Mechanical isolation (like the Ferox or Fluid jacketing on PAD PC's) seems to make a huge difference.

. . . . and to Floyd (last, but so not least -- it's your thread after all -- and you asked the question!) OK, at least with respect to mounting and placement of speakers (that is, putting aside associated gear and cables for a moment) for best/cleanest bass output, and MOST accurate/articulate transient response, ALL LOUDSPEAKERS should be lag-bolted to a concrete slab, or, to a 1.5" double-thick plywood sub floor! Can't manage that? OK, spikes are second best (and not second by too much really, but read on.) Spikes should first of all be VERY SECURELY ATTACHED to the bottom of the speaker. And if the speaker weighs over 100#, use 4 spikes; 3 puts too much stress on the contact point with the floor. If you have a joisted wood floor, there are certain rules and strategies for locating the spikes relative to the joists underneath in order to minimize rocking or swaying. If you have carpet + pad, the spikes' sharp points must PUNCTURE THROUGH the carpet + pad, and BITE INTO the concrete slab or wood sub floor underneath. Even the heaviest Wilson or other Mega-Boom-Buck loudspeaker, placed on the THINNEST carpet, is going to ROCK BACK AND FORTH in the opposite direction of the drivers' travel. YOU MIGHT NOT SEE IT, but it WILL MOVE!, and the speaker's performance (as anticipated by the speaker's designer, anyway) will never be realized. A loudspeaker enclosure MUST NOT MOVE. All the energy from the movement of the drivers MUST TRANSFER DIRECTLY TO THE AIR!! All the gear-swapping you can afford will never improve your loudspeaker's poor performance if it's due to poor speaker mounting technique; and what's worse is most folks go for years (or FOREVER!) without realizing how much better their speakers could sound. SO TAKE CARE OF THAT FIRST! And if you CAN'T take care of it first, then you'll have to (temporarily) PUNT: once you SORT OF KNOW (within a couple feet) where they will go, place the ALREADY SPIKED loudspeakers on 1.25" (kitchen counter thickness) by 2ft. (+/--) plywood squares, with short, looped pile, outdoor carpet (slides best on the floor) GLUED to the bottom of the plywood -- or use four small casters if you really want to make life easy ;--) When you think you know where you want the speakers, have a friend help you take them off the dolly and onto the floor. Set the spike points TEMPORARILY, on floor protectors. If you have a really heavy speaker, set the metal floor protectors inside nylon piano leg protectors, so you can still slide the speaker around a little bit. Eventually though, you must let the spike points bite into the floor -- you can only forgive yourself for NOT doing this if you have a pristine polished marble or parquet floor and you don't own the house!!

Floyd, you have been madly (and expensively) beating around the bush, and I feel truly sorry for you about that. Almost ANY piece of the gear you mentioned you owned or borrowed I could use as the cornerstone of an EXCELLENT and SONICALLY SATISFYING audio system; but not if I approached the project as you have done so far! So FIRST, find out where those Sashas REALLY WANT TO BE for the best 2-channel reproduction. All you need to know right now is where you want to sit so that you can figure out where to place your front end equipment most conveniently (to the SIDE, of course ;--) Things like room acoustics, the final choice of all other gear and cabling are all lower priorities right now and can be refined as time goes on. Your SECOND PRIORITY should be discovering an amplifier that sounds the best to you with the Sashas. YOU CAN USE ANYTHING FOR A SOURCE, the crappy-er the better, and hook up the amp and speakers with crap too! -- 18 AWG lamp cord will do fine. I'm serious. Using junk associated equipment won't change the winner of your amp contest (I promise!), and things will only get better, right!? Your THIRD PRIORITY should be the speaker cable. You will probably want to make a short list, but they should ALL have certain things in common: Low strand count. Large conductor size, >10 AWG total size for each run, pos and neg. Good mechanical isolation (a fat outer jacket ;--) SIMPLE INTERNAL GEOMETRY. Simple internal arrangement of the conductors, combined with a low strand count (under 6 strands per conductor) USUALLY insures good (meaning low) capacitance and inductance characteristics (but check out the actual specs with the manufacturer.) "Good" means capacitance under 20pF (picofarads) per foot, and inductance under 0.4µH/Ft (millihenries) per ft. This will insure your speaker cables aren't secretly operating under the radar as TONE CONTROLS!

Once you've covered these fundamentals Floyd, you can evaluate/refine everything else and pretty much in any order you like (with certain exceptions.) In the meantime, if you like the Sashas as your loudspeakers, then you need to put them (horses) in FRONT of all those other little carts, or you will NEVER make any satisfying progress. Like I said, I could put together an incredibly satisfying system out of the stuff you (still?) have on hand. But I already have a great system, and I'm going to go listen to it right now! And so should the rest of you. And IF you're NOT HAPPY WITH YOUR SYSTEM, then for God's sake get to work! But work smart; and TAKE CARE OF THE BASICS FIRST! THEY ARE: both in order of importance and deployment:

1. SOLID SPEAKER-TO-FLOOR MOUNTING TECHNIQUE AND CAREFUL CHOICE OF (PERMANENT) SPEAKER PLACEMENT.
2. EVALUATING THE AMP YOU LIKE BEST WITH YOUR SPEAKERS -- REGARDLESS OF HOOK-UP WIRE
3. SELECT A SPEAKER CABLE THAT IMPROVES THE SYNERGY ACHIEVED IN No. 2 BY AT LEAST TENFOLD!

If carried out in an orderly way (after selecting a loudpeaker you really like;--) these three PRIMARY decisions/solutions/purchases should not have to be repeated for a LONG time!
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The caster crack may be unwarranted. The contact patch approaches that of a spike with the obvious benefits of a non-thumb-tacked floor and ease of positioning . The carpet issue makes it academic, eh? My $.02.

On the cable side of things, perhaps a visit to bettercables.com might help. They use Belden wire and minimal bs, give them a try! One more option is the cable lending library offered by the Cable Company. Good luck in your quest.

Hi, I own the proteus provectus praesto. it does have a killer good beautiful midrange, loads of resolution with a ease/naturalness on the wilsons. I've had venestas in the past along with dominus and 20th anniversary.

I do think you'll like the spikes. especially with your carpet...

the glare you comment on, I really don't think it's the speakers...it's system and placement (read matching).

transparent cable (mm2 only i think) has a special synergy with wilsons-so these should be considered also.

what are you using for power conditioning/cables?

good luck, great system !

Dan,

Thanks for responding. Along with trying the PAD speaker cable I have a friend's MIT Oracle 2.2's and the bass *is* faster than the PADs. It is also a bit more open sounding, but I love the PAD's midrange.

Nsgarch: my system page isn't up to date (and the Atma-sphere amps in the photo were borrowed at the time).

I'm not currently using my Lamm M1.2 Ref amps nor the BAT REX. In trying to clean up glare from my Sashas I found I got less distortion from my Joule LA-150 SE and Spectron Musician III (bybees/v-caps) amps.

Speaker position is also slightly closer to the back wall. Yes, I use casters, but I'm unconvinced that spikes will make that much of an improvement since my carpet is thick shag with thick underpadding and I feel the speakers don't budge.

But I guess I should try putting the spikes in and see for myself. I really appreciate your comments. I'm realizing as I write this that I have spoken with Jim Aud once - I run my Spectron amps as monoblocks and this requires a Y-cable configuration and Spectron sent me to Jim to order a pair of Y-XLR's. He was very easy to speak to. Gee I wonder what 'model' cable he would have used.

My Spectrons are supposedly very senstive to Power cords and I'm using Panagea AC-9's. Maybe I should try PAD PCs as well?

Oh, sorry, didn't mean to predict. I meant to say "sounded slower and less defined"

I can tell you from my experience in my system the PAD will sound slower and the bass will be less defined than the Mogami. ME, YMMV, etc.

I use PAD Venustas systemwide. Using all Purist cabling (and of a single model -- mostly) makes the synergy obtained with a single cable solution a REAL and AMAZING EXPERIENCE! This phenomenon is often raised, but I never heard it so well demonstrated as with the Purist products Other brands I've tried this way (single cable solution) include MIT, Straightwire, and Levinson GEL cabling. So that's my first comment.

It's easy to obtain electrical specifications/characteristics on any Purist products. Some products have their specs published online; other products you'll have to call. But c'mon . . . . if you're really seriously interested in ANY specific brand of audio gear, it only makes sense to establish at least a telephone relationship with the manufacturer; and I encourage you to do that with Purist. The owner's name is Jim Aud. He's soft-spoken and understated -- a REAL ENGINEER who knows his stuff, and not one of those "trial-and-error" gasbag, used-car cablemakers (think Virtual Dynamics ;--) The other "equivalent" product line (yes, even better than Siltech!) with some real engineering chops behind it, is Aural Symphonics in Phoenix. Tommy Dzurak, owner. (I use his AT&T glass fiber optical cable for my Wadia stuff ;--)

Back to Purist. Their Venustas line represents the MOST value-per-dollar of any cabling (including other Purist models) out there. Especially when you take the time, as I did (at first, just out of curiosity) to compare other excellent products with closely similar specs on a price per foot basis.

OK, I already mentioned power cords. As for your speakers: with those Wilsons, you need low INDUCTANCE speaker cables. The Proteus line is Purist's (only) SOLID conductor line, and therefore exhibits solid conductors' characteristic low CAPACITANCE -- an important quality (in a speaker cable) if you were driving electrostats. However, the Venustas line also has very low inductance AND capacitance; and should be fine with your Wilsons (and your other gear as well.) I DID break away from the Venustas line and used PAD's (very expensive) Dominus line power cords, simply because with my amp and power regenerator, the difference was huge, and obvious! However, I knew if I wanted an "all-PAD" system, I would have to be fiscally realistic ;--)) So I went for the Venustas. Interestingly my first PAD cables were Jim Aud's 'personal' Venustas tonearm cable and a pair of Venustas RCA IC's (phono preamp to preamp) he sold me for half-price when I wandered into his room at CES 6 years ago! He knew a customer whan he saw one!!

As for long runs of interconnect, don't worry about anything under 16 meters or 50 feet. And if you're using balanced IC's between pre and amp, you can go 100 feet or more. Purist Audio Design's single most important "claim to fame", and the first thing you notice, is that all their cable products have the quietist blackest backgrounds of any cable you've heard.

What strikes me about your system, is you paid a premium for all that that expensive Wilson engineering, based of course on properly mass-coupling a loudspeaker to the ground, and there they are -- on CASTERS?!!! That means that everything else up stream (expensive amps and sources) represent a tragic loss of great sound, not to mention their cost and all your effort. SURELY, you can find a more creative way to solve your HT + 2-CH issue?? And gosh, you'd get so much better/cleaner bass out of those great single channel tube amps, if you'd get each one right next to its respective speaker in order to get the most out of the tube amps' limited damping.

Anyway, putting cable selection aside for a minute, I see you've acquired some beautiful high performance gear which could provide some REALLY AMAZING 2-channel audio experiences, if only you'd think more critically about how it should be arranged and connected. Instead, you seem to be consumed with trying to have the best of both worlds! And it's simply NOT possible, no matter what anyone says -- and from what i see, it appears that most of your money is on 2-channel -- so that's where I'd focus, if it were my stuff ;--)
.

Hi Floyd,

Driving the long cable from the PARC will make the output impedance of the preamp irrelevant. The only situation in which the output impedance of the component preceding the component driving the cable would matter (as far as that cable is concerned) would be if the component driving the cable were a passive preamp, or some other completely passive and unbuffered device.

I would characterize the Mogami's capacitance as being moderate, or perhaps a little on the low side of moderate. It is low enough to be negligible at more typical lengths, when driven by most components (including the Rex). One of its major strong points is its noise rejection performance.

Given the low output impedance of the PARC, I don't think that the sonic differences between the Mogami and other cables you may consider can be predicted based on technical factors.

Regards,
-- Al

Al, thank you for the advice. I thought the thing Mogami had going for it was low capacitance. As you mentioned, it doesn't seem easy to find the capacitance of the PAD.

At the moment I'm not using the REX, I'm using my Joule LA-150 SE preamp. It has an impedence switch inside to handle longer runs but I haven't switched it (at least not yet) because I am going out from that into a Rives PARC (which is balanced) and from the PARC I'm using a 40' run to the amps. What I don't know (and maybe you can shed some light on it) is what matters more in this situation - the output impedence of the PARC or the Joule.

I'll add to my previous post that a very experienced audiophile I know uses 30 feet of Oyaide PA-02 in a balanced configuration, with excellent results. It has much lower capacitance than the Mogami 2534. He has compared those two cables, and as might be expected the Mogami's presentation differed, in the direction of being more relaxed.

The Oyaide is about $28/meter in bulk (unterminated) form.

http://www.oyaide.com/e_audio/audio_products_files/pa-02.htm

http://thecableco.com/product.php?id=6451

Regards,
-- Al

What components are you connecting? If the connection is between your BAT Rex preamp and the power amp, and the existing cable is Mogami 2534 in a balanced quad configuration, the cable's capacitance is high enough to be causing a small but probably perceptible rolloff of the extreme upper treble, and a slight dulling of transient response, due to its interaction with the high output impedance the preamp has at high frequencies. See Stereophile's measurements.

I can't predict whether the PAD cable would be better, worse, or similar in that respect because its capacitance doesn't appear to be specified.

Unless the output impedance of the component driving the cable is low (and the Rex's is not low), I would not invest in a 40 foot cable without knowing what its capacitance per unit length is. And assuming you want the cable to behave in as neutral a manner as possible, and if it is the Rex that is driving the cable, you should try to select a cable having significantly lower capacitance than the Mogami 2534.

Finally, I would be cautious extrapolating from the experience of others if the component they are using to drive the long cable has significantly different output impedance characteristics.

Regards,
-- Al