Unbalanced to balanced VPI junction box change?
You would not need to upgrade the tonearm wiring, it just plugs into the connection box with the Limo connector already there. The wiring inside the box are so short lengths 1 to 2 " that I would not worry about that what so ever. Question is why would you want to change the box, do you have a balanced phono stage ? Good Listening Peter |
Why rewireing or upgrading tonearm wiring? You can use common ground + signal pins on each balanced recepticle. There's a 5-pin balanced recepticle as well with R+-,L+-,G just like in this phonostage: http://www.violectric.de/Pages/en/products/ppav600.php |
Pbnaudio is right in that you should be able to swap out the junction boxes. You should be able to use the Nordost you already have in the tonearm. Looking at your system, you show a Sim phono stage. Its fully balanced, of course, so it does make sense to switch to balanced on the TT. If it was my system, I would do it. It shouldn't cost anywhere near $1000 unless you need a new cable to go from the TT to the Sim. |
If you plan to run the cartridge (which is an inherently balanced source) in balanced mode, one thing you might consider is the fact that you will have a low impedance balanced line connection, which in plain English means that you will not be able to hear any differences at all if you change the wire. This is because a true balanced line connection has that much immunity to interconnect cable artifact. So no worries! |
ZD, Ralph's contention just applies if certain criteria are met, and they are very often not met. See his post here, in which he explains further, and also offers what I consider to be a highly persuasive proof of that contention, at least for line-level interfaces. I would add, though, that most high output cartridges, such as moving magnets, will not meet those criteria, and their response in the treble region can be profoundly affected by phono cable capacitance. Also, cable capacitance can even make a difference when it comes to low output moving coil cartridges. See this post by Lyra cartridge designer Jonathan Carr, starting with the paragraph that begins "I should now debunk another myth ...." Best regards, -- Al |
Al has got that right. In addition Jonathan Carr's input mirrors my own experience in the design of phono preamps. **As a general rule of thumb** if you can hear differences between balanced cables it means that some aspect of the balanced standard is not being supported/observed by the equipment involved. I don't mean to derail the thread, but to add to Al's comment about high output cartridges (moving magnet), they are high enough impedance such that the cables play a role, not only that but I have yet to find one that loads properly at 47K. Usually to get them to sound right the actual correct load impedance is much lower- for example on many Grados the right load impedance seems to be around 8K-12K. Sorry for the derail. |
I have a totally balanced system (all Ayre components) and can readily hear the difference in cables.... I have a lot of respect for Ayre, but regardless if you can hear differences between the cable, some aspect of the balanced line system is not being supported and is allowing the cables to manifest some artifact. Here are the standards: 1) pin 1 ground, pins 2 and 3 carry the signal out of phase with each other. In the US pin2 is non-inverting. 2) The signal occurs between pin 2 and 3; pin 1 is ignored and is only used for shielding. 3) The cable will have a twisted pair for the signals, within the shield. 4) the connection will be low impedance (LOMC phono is a good example- quite frequently the cartridge sees 100 ohms or less at the input of the preamp) such that the source can drive 600 ohms without loss of bandwidth. It is items 2 and 4 where most high end audio products don't adhere to the standard. The reason this standard was created BTW was to eliminate interconnect cable interaction with the sound. Think about recordings made in the 1950s and you will see what I mean- quite often in these recordings the microphone signal had to travel up to 200 feet before it arrived at the tape recorder, yet obviously as we can hear the signal somehow arrived in good condition. This was entirely due to the use of the balanced standard. The implication here of course is that the cost of the cable has nothing to do with how it sounds. I have always thought that audiophiles would be interested in a means to get the interconnect cables to not 'editorialize' upon the audio signal. You would be surprised how difficult it can be to get across what the benefits are. For example the length of the cable or lack of it has no bearing in the benefits derived by being balanced. At any rate, if you can hear differences in cables as you have mentioned, it does in fact mean that the equipment is not supporting the standard. |
That's good! Here is something to consider- if you can hear the effects of cables in your system, I would guess that you installed the cables that sounded better. Now if you have been at this a while, you probably have replaced cables before, through a similar comparison method in your system. What I want you to consider is that if you can hear a difference between cables, that its not a matter of one is right and the other is wrong. The fact is that both of them are wrong! How do we know this? Next year, the manufacturer of your cables will offer a newer better sounding version, or there may be an offering from another manufacturer that trumps them, or maybe a more high-buck version from the same manufacturer. So we know that while they might sound nice, better performance is available. OTOH, if the equipment involved supported the standard, then you would not hear any differences between the cheapest cable and the most expensive. I have seen this demonstrated in spades many times. Its not about noise, its about how the cable sounds. Again, I often get pushback on this subject but I'm not making it up- your LP or CD collection is my proof. You know how quite often audio engineers will say that cables don't make a difference? In their world (pro audio) that is the case because pro audio equipment has to support the standard and balanced cables are what they use. IOW what we are talking about is the ability to control or 'swamp' the individual characteristics such that whatever makes it sound good or bad is no longer relevant, instead the technique is going to force the cable to do its job without editorial. A LOMC cartridge running balanced, with a low impedance load at the preamp where the preamp ignores ground and only looks at the pins of the cartridge for the signal is the ideal situation. Although LOMC cartridges don't make much voltage, they make a surprising amount of current- not many preamps could drive 100 ohms! So this is one area where if the preamp is set up right, the cable need not be expensive yet the cartridge can still sound its best. |
To get back to the original question, if the OP's existing single-ended Valhalla cable has only one conductor to carry signal plus a different kind or character of conductor to carry the ground side of an SE hook-up, then indeed he may want to change the cable for one that affords two identical conductors, one each for each phase of the balanced output of the cartridge, plus a third to ground the shield, tonearm, phono stage, etc, which connects to pin 1 of the XLR connector, in Ralph's scheme. However, spending $1000 to do this is just not necessary. Buy some very thin gauge high purity copper or silver wire (according to preference) and some braided shield, from Michael Percy audio, and learn to do a little soldering. You could easily build a very high quality IC for under $200 that way, or you could internally rewire the VPI box for much less. |
Atmasphere, "IOW what we are talking about is the ability to control or 'swamp' the individual characteristics such that whatever makes it sound good or bad is no longer relevant, instead the technique is going to force the cable to do its job without editorial." I have a lot of hands on experience with audio but nowhere near the technical knowledge that either you or Al possess. Assuming the above statement is true, are there any tradeoff's in sound quality? When you say "swamp" or control the signal so that the cables no longer have a sound of their own, is there a penalty to be paid in another area for things to work like that? Maybe less detail or resolution, dynamic contrast, that type of thing. The way you explain it, it almost sounds like something is being forced. Please keep in mind, I'm not saying you are wrong. I just don't know. In my experience, when you make changes, there's usually some type of trade off. At that point, of course, the subjective comes into play in that you pick what you are willing to trade, and what you need to keep. I'm just trying to figure out if you loose anything by going with balanced standards. |
^^ That is a good question! It has to do with how the source (phono cartridge) is driving the load, which is to say that the source impedance should be lower than the load by about 10:1. In the case of LOMC there does not seem to be a downside. LOMCs can drive low impedances with ease. If we are talking line level, the equipment driving the cable should be able to drive a 600 ohm load. In the old days this was done with an output transformer (in the studio). These days to do this you need a preamp that has some guts in the line section to drive such a load. Usually this results in a lower output impedance from that line section as well. Whether all this is a down side or trade-off is hard to tell; we solved the problem by doing a direct-coupled vacuum tube output and if anything it seems to sound better for it. I think some might argue that the signal path is more complex when going balanced- twice as many parts is the old myth there (it does not take twice as many parts). I don't think the signal path has to be more complex; in our case we only have 3 stages of gain between the LOMC input and the output of the line section- I can't speak for all preamps here, but as far as I can tell you don't loose anything with the balanced line system. Again, the amazing number of stereo LPs from the 1950s that are still sought for their excellent sound should tell you something. |
Thank you for the great info, but i am confused as ever. Let me clarify, i was refering to needing to upgrade to balanced IC and not tone arm wiring. The vpi balanced junction box comes with the Valhalla wiring. My dealer was explaining the balanced concept and lost me. I do have a preamp that accepts balanced input. Will any balanced cable work? If makes a difference and since my phono preamp accepts balanced connection i thought of taking full advantage of it. Thank you all. |
Atmosphere...you're absolutely correct. I found that the high priced spread often is not as good as the lesser ones. I feel that there is no such thing as "The Absolute Sound". Yes, there are qualities that we appreciate being reproduced, but I've played in a number of venues....Alice Tulley sounds different than Carnegie which sounds different than Boston's Symphony Hall.... My violin sounds different in my practice room than in my living room just a few yards away. I dare say, I've never heard my violin the way my listeners hear it....my instrument is under my left ear. Even when I have a another violinist play my instrument as I step back to listen, her/his manipulation of my bow is different than my technique...and therefore sounds different. I have tried just about every brand of string on my instrument...yup, they all sound different, and sound different with the amount of hours you log on them. There is no right... What I try to do is construct my listening to what pleases me...that makes me smile, and be damned the specs. |
