Hi,
Does anyone have experience and recommendations for (Ultra) Low Capacitance Interconnects between a SUT and RIAA / Phono Stage / Pre-Amp.
Thanks,
Nige
The best Iâve used is also surprisingly affordable - Van Damme Silver Series âLo Cap 55â - and it isnât just low capacitance, its overall LCR is very favourable.
Not sure if anyoneâs offering it as a full assembly. Iâve used Neutrik Profi Plugs in the past - which are a very tight fit - but with some careful prep and a little grease (seriously) fit well, and are sonically benign even if lacking any appealing âfooâ marketing BSâŚ
1 Like
1 Like
Those nasty-ass cast-brass Chinese plugs will fit like a welly on a willy and are only fit for your daily smashing-things-with-a-hammer exercises.
HTHs 
2 Likes
Still want ultra low capacitance with Duelund plugs!
1 Like
Is there a reason, other than âthe interweb told meâ, that you are looking for an ultra low cap cable from sut to phono?
It isnt something I have ever been particularly bothered about, and tend to use the same type of cable as the tonearm to sut most of the time 
I can see the rationale for an MM cart to phono, as the total capacitance of cable plus phono input interacts with the cart to produce the hf resonance, which may help extend hf performance, or not. But i am not seeing that with the sut tbh
1 Like
The SUT will (approximately) âreflectâ whatever capacitance is on the secondary side as N-squared times that capacitance on the primary side. So a couple of hundred pF on the secondary of a 1:10 SUT looks like 20nF when viewed from the primary side, which is what the cartridge sees, of course. Then again, MC cartridges are low impedance devices and will cope with high capacitance much better than an MM would. I donât know enough about cartridges to know whether 20nF would bother an MC.
In the real world SUTs have resonances too and do we have to worry that one of them might interact with whatever capacitance is on the secondary ?
Thanks all for the feedback.
I think I may have found a 2nd hand pair local to me for a cheap price to play with.
As to @sjs - Its a ârecommendationâ of the SUT manufacture, however this is mostly backed up by what others say on forums, but not entirely hence me wanting to find a âsensiblyâ priced cable set to play with against what I already have.
As this will be used with my Io ltd Cartridge and SUT then I want to give the set up the best chance to sound / perform as good as possible.
Thanks.
Nige
âKeeping the math simple, all of the capacitances at the secondary of the SUT are in parallel and simply add and are reflected to the source by the turns ratio squared. In your case with a 1:20 and 100pF at the secondary the primary of the SUT appears as 40,000pF. You then add the tonearm cable 100pF in parallel to that for 40,100pF. This clearly shows that when it comes to cable capacitance it is the cable from the SUT to the phono stage that should be kept as low capacitance as possible. The rub here is since this is a high impedance node, shielding is also a must for quiet operation. Unfortunately shielding adds capacitance so you move a little forward in noise and a little back in HF extension. Keeping the cable as short as possible (0.5m or less) helps on both counts.â (Dave Slagle:)
Trouble with keeping the cable short is the potential for hum from the SUT being in close proximity to other transformers.
2 Likes
Basically, exactly what Iâve been told, but put way better than I ever could have⌠
This is certainly true in real-world practice, but only because manufacturers choose the cable dimensions (and, to a lesser extent, materials) that they do. Perfectly good low-capacitance shielded cable could be made by expanding the outer diameter and, thereby, increasing the distance between the signal conductor and the shielding braid. Thinning down the signal conductor would also help, as would lowering the dielectric constant of the insulating layer (e.g. by replacing some of the plastic with air, say). The problem is no-one makes and sells stuff like this, I guess because there isnât enough demand. There would be other consequences too - large diameter cable isnât flexible and doesnât fit the available connectors, thin signal conductors are fragile and resistive (although not very), foaming the insulator can put a good deal of air into it but solid plastic has a relative dielectric constant of 1.5 and airâs is 1.0 so the difference isnât going to be large.
1 Like
Enormous = Happy (Said many an audiophile and most of my unhappy previous partners.)
2 Likes
Iâve got a 0.5 metre pair of Audio Note Pallas interconnects somewhere (copper version, not the astronomically expensive silver ones) which I donât use (too short). Let me know if youâre interested.
Call that a cable ?
is a cable !
Thatâs the 30 year old me with a few metres of 75cm dia coaxial transmission line containing rather more than a ton of deionised water. We were aiming to store a lot of electrical energy, so we wanted maximum capacitance, and on a scale where the dielectric constants of air and plastic are 1 and 1.5, water is 9 ! The whole structure wasnât exactly flexible though.
3 Likes
Ok, i get the maths, but that suggests that the single biggest factor is the ratio of the sut as it has the most significant effect in the capacitance reflected from secondary to primary
While the input capacitance of the phono stage is likely to swamp the cable capacitance.
Reflected capacitance may be an issue, but it seems the cable is the least influencial of the three parts at play
As is usual with cables,(Assuming they are correctly sized and fit for purpose) they may have a very small influence but compared to rest of the system it is tiny.
The whole industry marketing system doesnât help and the profiteering is extortionate.
The biggest single factor to a good system is the speakers and their interaction with the room.
Lots of audiophile nervosa have very little control over the furniture that goes in a room and sound quality is a long way down the list of what is acceptable to those who make the decisions, as is any attempt at room treatment to get rid of reflections etc.
This leads the audiophile to faff around with things that wonât get noticed but gives them some semblance of control so they buy into the bollocks that is the cable industry and convince themselves it makes a difference.
Iâve tended to find the phono chain sees more âdifference / importanceâ than elsewhere with cables.
4 Likes
By far the best picture on this forum today (and that includes whatever home brew Maureen is working on in his Meme lab)
Yes. An MM cartridge trying to drive too many metres of cable really will sound (and measure) very different.