Connect the TT to the phono stage with shortest cables possible. Then run long interconnects to the pre.
The inductance of the phono interconnect will vary directly with the length and this could cause issues for the loading of the cartridge. If the specs are known for the phono interconnect then you could potentially account for the high inductance by chaning the loading settings on the phono pre. |
It is not advisable to have long cables coming directly from the turntable, which is handling the very low level signal being generated from the phono cartridge. You should go with the option of keeping the phono stage relatively close to the turntable, and having the longer set of cables handling the higher level output of the phono stage. |
I doubt that you will get any support in favor of long IC between the table and phono. I don't even like the idea of a long IC between the phone and pre. |
If the phono pre has balanced outputs, then you're home free and can run long lengths to your preamp without problem. |
Dear Ninox: IMHO always that's posible we want to connect the cartridge signal coming from the tonearm/TT as shortest is posible to the phono/preamp stages.
The cartridge signal is extremely delicate and sensitive due to its very low output and as more lenght it has to run as more degradation happen. In the other side a longer IC cable means higher capacitance that affect the quality performance of your ADC cartridge.
Now, the output impedance of your Moon 110LP is low enough ( 50 ohms. ) for you can run long cables to the amp with out trouble.
Regards and enjoy the music,
R. |
I agree with all the opinions expresses so far. I have my TT far away from the system pre amp as you do. It is acoustically isolated from the loudspeakers.
My only advice is to use an RS meter and find a place with the least bass nodes and to use shielded ICs from the phono preamp to the system preamp. I use Blue Jeans cables LC-1 which is very low capacitance and is double shielded to eliminate outside interference. It has very solid crimped connectors and is well made. |
Thanks everyone, that's really helpful. |
connect turntable to phonostage with 1m long IC cable regardless weather you're using balanced or unbalanced arm wires. that's how all of the sound pickups designed to synergise with the cartridge inductive load and best pickup performance. per-meter active resistance of tonearm wire does a trick of increasing detail performance of cartridge. length of phono to preamp cable is less of importance, but shorter ones may give more benefits depending on your rest of equipment. tru differentially balanced stages pretty much don't care of the output wire length at all. |
OK- I am going to be the lone voice here. Most LOMC cartridge don't make much voltage but they do make a surprising amount of current, otherwise you could not load them at 50 or 100 ohms and get away with it.
So I am asking here that you all think about that simple fact.
What this means is that the cartridge and cable is a fairly low impedance system, and the length of the cable is thus not nearly as problematic as suggested above. What the real problem is: the cartridge has an inductance and the cable has a capacitance. This will not cause problems at audio frequencies, but will cause issues at Radio Frequencies.
This is true even if the cable is only one meter BTW.
So what you **may** have to do is adjust the loading resistor, should it be the case that your preamp cares about RF coming into its phono input (some preamps, particularly solid state preamps, don't like RF at their inputs and this can really affect the sound).
Bottom line: you can very successfully run a 4 meter interconnect. You may experience some artifact from the cable, but if you run it balanced you can eliminate that.
Now if you are using a high output moving magnet, then its a different deal and you will find that because its impedance is higher, it is also more sensitive to the cable. |
Ralph(Atamsphere) What is meant by if you run it balanced aren't all phono cables RCA unbalanced? |
Ralph,
The OP is not using a LOMC. His ADC XLM is a MM cartridge, so the last sentence of your post is the only one applicable to *him*.
That said, those of us who use LOMCs appreciate your knowledgeable input, as always.
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Nick sr phono cables can be balanced in the form of 5-din connector. If you separate ground for each channel you'll get fully balanced phono inputs.
Conventionally there are no balanced(to my knowledge) phono cables, but seen phonostages with balanced XLR and 5-din inputs. |
Nick, No. The vast majority of cartridges are inherently balanced output. So it is possible to use a true balanced connection from the cartridge to the phono input. It especially makes sense to do so if you have a truly balanced phono stage. Such products are still rather rare, but they do exist. Atma-sphere preamplifiers, MP1 and MP3, are examples of such. The connection from the cartridge requires three discrete wires (positive and negative "hot" wires derived from what are labeled "hot and ground" on the cartridge body, and a separate ground) into an XLR connector, rather than the two normally associated with RCA connection ("hot" and "ground", as per the color-coded labels on the cartridge body). |
Thanks Doug, missed that in my fanaticism. In that case the capacitance of the cable is playing a big role in the loading of the cartridge. If it were me I would measure the capacitance of the cable, subtract the capacitive value of my one-meter cable, and then pick a capacitor of the resulting difference value. I would then plug it into the loading strip of the preamp, and see how it interacts with the cartridge. If a roll-off is detected, a lower capacitance cable should be found of a preamp could be placed by the 'table itself. But if the cartridge is not sounding rolled off then its good to go. |
The bottom line seems to be that without a balanced phono stage, you can't have a balanced connection even if cartridge output is inherently balanced.
Or could you use a Jensen transformer (Balanced line in to SE output)as was suggested to me in another thread?
Also I assume that by using a SUT, it would play the same role as the Jensen, while stepping up the voltage? |
Any SUT is capable of receiving the signal in balanced domain, so you can run balanced from the cartridge if you have an SUT, regardless of the phono section. There are indeed balanced phono cables available too.
You know that funny ground wire on the single-ended (RCA) cables that no other single-ended source seems to need? That is there because you are taking a balanced system and running it single ended. A balanced system has a ground system that is independent of the signal, and has to be grounded separately. If the cable were balanced, it would be pin 1 of the XLR. |
Ralph, when i rewired my tone arm recently, I used a Mogami 2549 cable, 2 conductor with a shield. The left and right +/- were connected to their respective blue and clear conductors and the shields from both the left and right wire were connected to the ground lead at the TT and left floating at the preamp end. The separate ground lead is then connected to the chassis of the preamp.
Is my understanding correct from the previous posts above, even though this configuration mimics a balanced connection it cannot be one given that the preamp input is single ended (RCA)? |
That is correct, but you are helping things by not using the shield for signal current. That reduces the cable's tendency to introduce artifact. |
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Ralph thanks for the response! It confirms what I thought. @EBM the unfortunate reality is that somewhere in your system you going to have long cables, be it speaker cables or interconnects. Unless of course you are using a Bose Wave system :o> |
Thanks again, this is very interesting. |
Due to the low level signal short cables are the best idea. |
That's what Ebm thinks, but in reality most of cartridges designed for 1m cable length. |
My advice is very good i have TW AC1 BLACK NIGHT 3 motor unit,BLACK NIGHT feet,battery power supply with TW 10.5 arm and Transfiguration Proteus cartridge with a 1 meter cable for best sound. |
One solution for running a perfect line signal the lenth of your house if necessary. This requires two "baluns", one for send and another for recv, plus Ethernet 6 to connect the two. Run the Ethernet from max of 2500 feet to "Baluns", and short RCA from "baluns" to component. This will give you a crystal clear signal from the basement to the farthest end of your house upstairs. |
Last night the local Thorens expert recommended I move my Parasound JC-3 to a shelf just below my TD 124. The arm is an SME 3009 Series III with Ortofon SME 30H cartridge. Should I use a 1 meter cable even though a half meter would be sufficient? I'm thinking of using Linn Silver cable.
db |
09-21-13: Dbphd
Last night the local Thorens expert recommended I move my Parasound JC-3 to a shelf just below my TD 124. The arm is an SME 3009 Series III with Ortofon SME 30H cartridge. Should I use a 1 meter cable even though a half meter would be sufficient? I'm thinking of using Linn Silver cable. It appears that the Ortofon SME 30H moving magnet cartridge has a recommended load capacitance of 400 pf, which is on the high side. And your phono stage does not provide adjustable load capacitance, so its input capacitance is probably smallish, perhaps something like 50 pf or even less. I couldn't find any info on the capacitance per unit length of the Linn Silver cable, but I suspect that it is unlikely to be more than around 50 pf/foot. So the problem you would probably have with either length is too little total capacitance. With a MM cartridge having too little load capacitance is likely to result in thinness somewhere in the treble region. You might want to consider using, at least experimentally, this kit, which makes possible adding various amounts of capacitance. It costs $46, and is sold by DB Systems (see the "Accessories" link). After determining the optimal amount of added load capacitance you could then install a capacitor of that value into the JC3, for each channel. Or, if you would prefer not to make any modifications to the JC3, using a pair of the capacitors that are in the kit in conjunction with good quality y-adapters would probably be a reasonable long-term solution. (IMO, that is. Other opinions about using y-adapters as a long-term solution will certainly differ in some cases). Regards, -- Al |
Thanks Al. I'll order a kit from DB Systems. The turntable currently has what looks to be a 1.5 meter AQ cable that I understand cost less than $200. I think really good vinyl sounds superb, a bit better than SACD of the same recording played on my Oppo 105 with analog to Cary Cinema 11a inputs set to bypass. The JC-3 also inputs to the Cary.
db |
The capacitance issue is very interesting. So as well as the transcriptors, I also have a Technics SL5200 turntable which I find sounds sort of flat and lifeless. It has an Ortofon Bronze MM with a recommended capacitance of 150-300pF. The Moon 110LP has adjustable input capacitance of 0 or 100pF. So I should have set the Moon at 100 I guess, assuming that the cables in the turntable are not so superb (basically 35 year old wires) but are unlikely to add up to more than 300?
BTW - using the advice you all gave me, I ran the turntable to the phono stage using the wires from the table and then ran long RCA from the phono stage into the stereo pre amp. Seems to work fine. Happy. |
Ninox, in the case you described just above my guess is that the total load capacitance would probably not be very far outside of the recommended 150-300 pf range for either setting of the Moon's input capacitance. And it's quite possible that you might even be within that range for both settings. So while I would expect the two settings to result in some difference in sonics in the treble region, both settings would have to be tried to determine which is preferable.
A point to be aware of, btw, is that the "0 pf" setting will not really be zero. It will be some small amount of stray capacitance in the connectors and internal wiring, plus some small amount of input capacitance of the circuitry. The "100 pf" setting will presumably be 100 pf greater than that amount.
Regards,
-- Al |
Al,
The input capacitance of the JC-3 is about 200 pF. I'll probably use Mogami 2549 cable cut to length for my application, most likely around 3'. I suspect LA Pro Audio can tell me the capacitance per foot. They've been very responsive to making cable lengths to my specification. The advice I'm getting is to keep the cable short without putting the motor of the TD 124 on top of the JC-3.
Thanks for your help.
db |
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09-22-13: Dbphd
The input capacitance of the JC-3 is about 200 pF. Interesting. I'm surprised it's that high. The optimal load capacitance for many and probably most MM's falls somewhere in the area of 100 to 300 pf. A phono stage input capacitance of 200 pf would make it impossible to optimally match nearly all of those cartridges, the possible exceptions being those in the 250 to 300 pf area when used with short lengths of low capacitance cables. How did you obtain that information? Best regards, -- Al |
DB, after checking further I found the following quotes from John Curl, the very distinguished designer who as you are undoubtedly aware did the electrical design of the JC-3. The quotes appear on pages 3953 and 3956 of this thread: There is a 100pf cap at the input to ground for the JC-3. Some criticism has made me now wonder if 50 pf might be better?
... My best guess at this time [May 20, 2013] is that the effective input capacitance of the JC-3 is 125pf or slightly less. I could drop that in half, and I might, in future. The potential advantage may not be worth much. I will think about it. Best regards, -- Al |
Thanks for the link, Nick. I'm going to try a pair of the 2549 Mogami cables.
Al, it appears as though there may be a capacitance mismatch, so I may need to add capacitance using the device you suggested after I install the Mogami cables. I'll do some careful listening first. The sound is superb with the AQ cables I'm currently using, with no HF roll-off or thinning. There is a low level sizzle that I can hear if I put ear close to the HF driver, but not audible to me at my listening position. I hope shorter cables carefully routed will end that sizzle. I think the 2549s are designed to resist such interference.
db |
Nick, I forgot to ask if you're pleased with the sound of vinyl using the Mogami 2549 cables. I'm close to ordering, but need to exchange the locations of the Parasound JC-3 and Sony 5400ES so I can determine the length more accurately.
db |
I think they sound great, since trying them on my TT, I also made myself a pair of 8ft ICs for pre to power amps connection. I used Canare connectors.
The green wire covered by silver tech flex looks pretty nice, I have pics on my system page. |
Nick,
LA Pro Audio recommends Mogami quad 2534 with ProFi RCAs. They are supposed to be exceptional for isolation with excellent sound quality. Nearly three times the cost of 2549s, but still not very expensive. I think 2.5' cables are all I need. I've been advised that I can use the existing ground wire. Lifting the TD 124 from its plinth is more than I want to try, so I'll leave that to an expert.
db |
Db,
Are you soldering your own terminations or will you be buying a finished product?
If you are buying the bulk cable, Redco sells the 2549 at 0.80$/ft and the 2534 at 1.12$/ft.
2549 has lower capacitance but not by much and the 2534 is better for noise cancellation. |
Nick,
I'm ordering a pair of 30" Mogami 2534 cables with ProFi RCA connectors from LA Pro Audio. They appear to be pretty nice and the cost is very reasonable. I'm using Mogami 2549 interconnects throughout the setup.
db |
Let me know how it turns, maybe I will need to tryout the 2534 too. |
