Does Everyone Use 2 Phono Cables with SUT
I just learned a rather expensive lesson from my audio dealer. I always thought I only needed a phono cable from my turntable to my SUT. By adding another phono cable (not interconnect) from the SUT to the phono preamp, I got a nice improvement in “efficiency.” Everything just flows better.
I guess everyone uses 2 phono cables?
Thank you all for the feedback and advice. I learned an expensive lesson by using a regular interconnect with my SUT. I think @atmasphere is correct. “Brand” probably is not as important as the cables capacitance. I’ll bet there are some decent phono cables, with very low capacitance, that can be purchased at a reasonable price. I believe someone mentioned Bobs Devices.
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@labpro As you can see cable capacitance is the name of the game when it comes to phono cartridges and SUTs. Its important to keep it down as much as possible. The transformer transforms everything- not just the output voltage of the cartridge. This issue is so important that it may well outweigh the cable brand or the like... |
Dave @intactaudio, thanks for this explanation. So my takeaway is that the higher capacitance of standard interconnects makes them problematic for use between a SUT and phono stage, especially if they’re not short and especially if you’re using a higher impedance cart and high ratio SUT. That would explain why I had a problem using the Denon 103 and EMT JSD 6 with an A23 T2 SUT with standard ICs of various brands and why I’ve gotten such a big change from switching to a phono cable that’s advertised for its low capacitance. Nice to have such a clear narrative on this!
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There is actually one substantial difference between the cable that feeds the input of a SUT and the one that comes from the output of a SUT. The difference is the impedance level at which they operate which dictates the situational needs. Lets assume a 10Ω cartridge and a 1:20 SUT. The cable from the cartridge will be operating with a 10Ω source impedance which is so low that length and cable capacitance is typically not much of an issue. Granted the signal levels are also quite low so noise pickup can be a concern so this wire is always typically shielded. Since it is a low impedance line, the penalty of the shield is minimal. On the other side of the SUT the cable sees 4000Ω and suddenly capacitance starts to take its toll. Due to the higher impedance shielding is a must for quiet operation but the capacitance that comes along with the shielding becomes the "gotcha". This is the main reason it is wise to keep this cable as short as possible. This is particularly important when you get into the higher impedance cartridges through high ratio SUT's dave
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Well thanks OP for a very helpful thread. I’ve had an A23 Hommage T2 for several years now but I’ve always found it underwhelming. However I was using it with .5 meter A23 interconnects (and a Kuzma 4 point on the inputs). I had the intuition that the A23 ICs were over-damping the signal but I never got better results with other cables (all of them ‘interconnects’ too).
So I got re-inspired by this thread. As it happens there was a used pair of Kimber TAK cu phono cables available at a reputable shop near me. Apparently they have a capacitance of 47.1 pF in the 1m length - the ones I bought are 2 ft long. I swapped them in for the A23 ICs and sure enough I found a significant and positive improvement. Everything opened up, top to bottom, and now the T2 finally makes sense to me. I’m using it with a newly rebuilt EMT JSD 6 cart and will swap in a new Zu Audio/Denon 103 shortly. Very nice to get the value out of the T2 after all that time. |
Cool, thanks for the follow up :) The Madake (at 0.23mV and 16 ohms) is not as efficient as most SUT-friendly MC's, but it's not impossible either. You'd typically expect coils less than 5 ohms for an output of 0.23mV (armatures using less ferrous material give less output). Optimally matching the Madake to a SUT is likely to be a delicate balancing act. I'd probably shoot for 20x. Not sure what the T2 is - sort of annoying they don't list the ratio bold and up front! |
As promised, I want to provide feedback after replacing the A23 “T1” SUT and plugging in the Auditorium 23 “T2” step up transformer.
As a reminder my Miyajima Madake cartridge has an output of .23mV and an impedance of 16Ohms. It turns out that the A23 “T1” is suited for cartridges up to 12 Ohms and the “T2” for anything over 12 Ohms. Swapping in the T2 had the following changes: 1. More defined soundstage especially at the edges 2. Less congested overall presentation 3. Had to turn up preamp volume by 20% 5. Slightly improved timbre However, it seems that I’ve lost some of the “weight” (meet on the bone) especially in the base and mid base. Unfortunately this is all happening while I’m trying to break in 2 new phono cables…..the subject of my original post.
I will check back after another 30 hours of breaking time on the cables to see if the base and mid base improves. |
OMG thats even worse. Unequal lengths - so the phase shifts at various frequencies through the cables will be different for each channel. I cant see how the Manley can drive 22ft cables without loss. You would be better off running short interconnects and decoupling the Beverage amps - extend the cables between the Beverage amps and crossover. I would expect significant gains with this alternate arrangement. |
Dover, AntiCables make several different cables for sale at different price points, and moreover they have recently revised their shielding for more coils per unit length. So which of their products are you denigrating here? I’m using their latest and highest end cable which contains separate and equal silver/gold conductors for hot and ground, respectively, (2 pair in each direction) with an entirely separate copper coil for shielding. RCA plugs are the best of the KLE product line, which I happen to like. I don’t perseverate too much on cables, although I do believe they make a big difference. I needed one 22-foot length cable to run from my Steelhead to the built-in amplifier on a Beveridge speaker; the other channel needs only about 12 feet. Where and on what gear have you auditioned whatever AntiCable you're referring to? For signal carrying, "thicker" is not necessarily better (in my direct experience, it's usually worse), and "thick" dielectric is almost always not desireable, but this is Off Topic. Let’s not get into another digression about whose cables sound best; I am only trying to help out the OP to think about the trade-off between shielding and capacitance.. You or anyone else can insert any other brand with low capacitance and effective shielding here. If you want, start another thread on cables. Finally, I don’t know what you mean by your last sentence: "Generalizations are dangerous...." Where did I generalize? I think you would agree that shielding per se adds to capacitance. And I did measure capacitance myself, in order compare the AntiCables to the cables I replaced, as far as checking specs (see above). Funnily, you say yourself above that the generalized AntiCable has a lower C per meter than whatever it is you use. QED |
Wow, you must like soggy bass and rolled off high frequencies - usual single strand attributes - no damping factor. ( Yes I have heard the anti cables ) The above statement is only relevant to the particular shielded cable you tried. Specifications for Anticables are 0.0095nanofarad/ft - 38 picofarad per meter. I use a high gauge stranded silver phono cable - twisted pair with double shielding - only measures 48 picofarad in total including the connectors despite using much thicker conductors than the Anticables. Generalisations can be dangerous - pays to check the specs. |
@lewm It isn't obvious to me how the spiral ground wire actually shields. It seems too loose to do much... |
Thats a great idea. It will give you an indication of whether the mismatch is having a significant affect or not.
Thats correct for the Homage. For the SUT to phono stage, you don't need a dedicated phono cable with the additional earth wire. You can run a single wire from the Homage earth socket to the phono stage separately. If you use the Auditorium23 cables thats how they wire it. The main advantage of dedicated phono cables are - they are designed for small signal and may have superior shielding - usually have the additional earth wire - ideally low capacitance ( which is desirable for your SUT to phono connection ). If you run a separate earth wire from the homage earth socket to the phono stage all you need are well shielded, low capacitance cables, and short as possible.
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dover, mulveling You both know more than I do. Understanding SUTs and MC Phono inputs or MC Phono Stages or MM/MC Combo units (individual selectable, one input and a switch somewhere) is one of the trickiest parts of moving into MC cartridge(s). IF an advanced stylus is not properly calibrated and aligned, it’s advantages won’t be heard, and damage can occur. Wrong x factor, wrong impedance, an advanced MC cartridge could be a little or a lot ’off’ of it’s designed potential superior sound reproduction. ..................................... I don’t like letting machines beat me, nor taking advice on faith, so I dug in, researched, read, found charts, surveyed the heck out of makers sites and vintage variations on hifishark. Most people, especially still working, don’t have the time or inclination, so they are at the mercy of .... That SUT is very expensive, has no adjustable parameters. OP may have already had it or been given it, in any case he is aware of the large impedance mismatch. ........................................................... I had a friend tell me his cartridge was MC low output. I checked it’s alignment on one of my arms, ... set tracking and anti-skate, and tried the same setting on my SUT as my MCLO, so we could compare them.. Not only too much volume, the entire frequency range was shifted. It had very nice range, imaging was there, but Annie Lenox; Sade, any voice was easily different. Weird. Everything was shifted in frequency together. I spoke to the person who rebuilt it, it is MCHO high output, we should have been using the PASS (skips the sut’s transformer, just sends unaltered signal thru. He brought the cartridge back, using PASS, everyone’s voices were ’right’. Now it’s full frequency, imaging, all there: it was hard to hear any differences between his and mine, after a while we both described what we heard from each similarly. The mismatch was not x factor/not too much signal strength, my mx110z phono input can accept strong signals, the IMPEDANCE mismatch was what made is sound significantly different, significantly 'wrong'.
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You don’t need a separate ground wire for the cable coming out of a SUT. A fairly low capacitance, shielded, 0.7m (or less) cable works great. Most shielded cables have shield connected to audio ground on ONE side, and this is the side you should hook into the SUT outputs (i.e. use the SUT as a hub for grounding). 90% of the time, I get no hum this way. I also have cables with a separate ground wire, and honestly this just complicates things - usually I end up grounding on the SUT side and leave the phono stage side floating (which ends up being the same scheme). The internally connected shield is cleaner for this scheme, and works great. The Bob’s Devices cables are constructed just right for this - my only complaint there is the Cardas RCAs grip jacks a little too eagerly. |
AntiCables make excellent “interconnects” which are both shielded AND very low in capacitance, because the shield wire is wound around the signal carrying wires. Therefore the shield is perpendicular to the field generated. They also make “phono cables” having a DIN plug at one end and RCAs at the other. XLR-terminated Balanced versions are available too. I’ve measured the capacitance and it’s vanishingly low. |
PHONO: basic advice: do not use interconnects to avoid potential problems. if so, as short as possible. SUT: tonearm phono cable with ground into SUT. Phono cable with ground out of SUT to Phono MM input and a ground somewhere nearby. I have had to extend a few din cable's ground wires, they were too short to reach a poorly placed ground too far from the phono jacks. Surprisingly/Confusingly: Fidelity Research FRT-3 has no ground attachment fitting. It's captive output cable has a ground wire with spade. Meanwhile, FRT-3G version has added a ground terminal on the back of the SUT. Captive output cable same, has ground wire with spade.
Tonearm ground wire can be separate, bypass the SUT, and go from the arm directly to a ground anywhere if needed. Some equipment, phono stage, etc have 'ground lift' to solve 'ground loops'.
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I mean, it’s fair to point out the mismatch. I encourage OP to try other SUTs or MC stages (but keep the T-1 on hand if he gets a lower impedance MC). But audio is audio, not cars, and here it’s as much about personal preference and happy accidents in system matching as it is about absolute performance. I’ve run cartridges with loading ratios close to OP’s. It softens the sound a little, it cedes a couple dBs of level, but it can still sound really really good in the right mix. If OP likes it, then I trust him, and I don’t think he’s a rube for enjoying it. Clearly the BIGGER mismatch he had was with the high capacitance cables! Sometimes the sonic impact comes from areas you wouldn't immediately suspect. |
I’m using an Auditorium 23 T-1 step up transformer. Sounds really good with the Madake and 2 phono cables. I am aware that the A23 “T-2” technically is for higher Ohm cartridges like the Madake. I had been using a high-end “tinned copper” phono and regular interconnect. I’d rather not mention the brand to be fair. That company does not publish the capacitance, but I’ll bet it’s much more restrictive than the Audience cables.
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Rather than confuse with labels, as has been noted above the sut to phono preamp cable should be excellent and low capacitance. Doesn't mean expensive per se. The lowest capacitance cables will be unshielded. Your phono pre might be better with shielding and this might raise capacitance slightly. It's a balancing act.
As an aside the lowest capacitance pro cables tend to be coax designed for instrument.
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Definitely makes a difference to use a “true” phono cable from SUT to phono pre. Also most phono interconnects come with a grounding cable, some installations may require this some may not, every situation is unique. With my own set-up my Kuzma 4Point comes with RCA cables at the back end and then connect directly to the catridge pins, which is still like using a dedicated phono cable from arm to SUT.
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Huh? that cartridge has a difficult combo of high 16 ohm impedance and low .23mv signal. It is the type that might need a SUT with individual gain adjustments and individual impedance what SUT are you using? You need to know the x factor of it’s input(s). cartridge .23mv; allowing for some loss: an x factor around 20: that would give you a signal of around 4.0mv., plenty for a MM Phono input. resultant impedance of xfsq 400 shown to a 47k mm phono input would be 117. guidance for your cartridge, 16 ohm x 10 = goal of near 160 ohms shown to MM Phono input.. to get ’shown’ impedance up, you need to lower the x factor. x factor 18 signal after bit of loss 4.0mv, still plenty xfsq now only 324, 47k/324: shown impedance now 145. closer x factor 16, signal say 3.5mv, many MM and High MC have this or a bit less. your MM stage has a ’sensitivity’, that is just above too low. xf16, xfsq 256; now ’shown to 47k input would be 183. now back to the issue of cable loss!
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Mulveling you are spot on. I was using a phono cable “to” the SUT and a “regular” interconnect from SUT to phono preamp. I have a Miyajima Madake cartridge (.23mV output) and the signal was literally getting lost. I recently added 2 Audience Front Row “phono” cables and everything snapped into place. I thought perhaps my speakers were not efficient enough. I almost headed down the path to replace my speakers! Lesson learned. |
If you mean 2 phono cables as opposed to 1 phono cable into SUT and one "regular" interconnect out of SUT, then yes. The cable coming out of SUT is possibly even more important. Many line-level audiophile interconnects have far too high capacitance to work well in this role (SUTs don't like capacitive loads) - large gauge wires, over-the-top of shielding, braided geometries. Phono cables are optimized for lowest capacitance, so they work well with a SUT. Most Cardas interconnects also tend to have EXCEEDINGLY low capacitance, and are excellent in this role. You'll also want to keep this run as short as possible, under 1m, because capacitance is directly proportional to length |
Sorry. Do you mean to differentiate between an "interconnect" and a "phono cable"? If not, how on earth did you connect your SUT to your phono inputs before now? To avoid using two ICs (or phono cables) in the SUT circuit, one option is to have flying leads (leads that are directly soldered to the primaries or secondaries of the SUT), so as to avoid any degradation due to RCA connectors. Also, many use a single set of leads from cartridge pins to phono input, or in this case from cartridge pins to the SUT primaries. Then you could have flying leads from the SUT secondaries to the phono inputs. |
