Advice please on phono stage-amp interconnect

New system furniture, had to move the phono stage, and it required swapping the 0.6m QED Performance interconnect (previously between phono stage and amp) with the 1m Atlas Element Integra (previously between DAC and amp) to make it fit.

There’s little if any perceptible difference in the sound of digital front-end with the QED now in place, but inserting the Atlas has brought a slight but notable brittleness (upper emphasis) to analogue one. I’ve swapped the ICs a few times to check and the difference is real. I’ve also tried different settings on the iPhono but the overall effect is still there.

Question is, what will be having more of an effect here: design/materials of the interconnects, and/or more its length? eg, what would happen if I got a 1m version of the QED?

I get that capacitance and impedance can contribute to the overall equation, and have read that high capacitance in an IC may cause the highs to be rolled off (might explain it re the specs below?), but don’t fully understand it tbh …

QED
Capacitance: 115pF/m
Inductance: 0.74uH/m
Loop resistance: 0.160 Ω/m
Dissipation Factor: 0.0012

Atlas
Capacitance 63.03 pF/m
Inductance 0.3735 µH/m
Resistance 0.1612Ohms/m
Impedance 77.05 Ohms/m

Any thoughts/suggestions much appreciated

 

Atlas is half the capitance.
This means it will sound brighter.
Different cartridges require more or less capitance .also the phono cable needs to be screened as phono stages/ turntables are affected by RFI noise.
Try listening to pink noise.
If it's too bright the. Capitance is too
High and vice versa.
If you care to , you can add cspitance
By buying a "Y" adaptor x 2
This will have a male to fit into phono stage and 2 female sockets for left and right. You need to solder across the hot and ground a 60 pf capacitor to a phono plug which is then plugged into Y adapter. The interconnect goes into those other phono socket .
This will restore capitance .
Or you could make a selection of different value plugs and try out
Various settings.
There are various interconnects
To suit all pockets .
Amplifier surgery are a U.S. Based outfit that hand build some superb
Cables at reasonable prices.
I use them.
They take about 3 weeks to build
And as i,m U.K. Based a few weeks
To deliver.
Good luck

 

I have my doubts about cap differences being audible. Lower inductance might give you a more forward sound. IMO, some cables allow certain frequencies to sing a bit more. If you can try a set of Wireworld Oasis 7, give that a shot. Less than $100 US used.

 

I wouldn't think it would be capacitance considering the cable that is higher capacitance is nearly half as long as the cable with lower overall capacitance, effectively don't both cables, being different sizes, have a close enough total capacitance as to be negligible in that regard?

.6 * 115 is about 67 pf, compared to 63 pf on the Atlas cable for the full meter.

Just something I noticed, not sure if it helps or not.

 

The capacitance of the cable between two line level active devices -- like a phono preamp and an an active preamp or integrated amp -- is unlikely to have any impact on rolling off HF. If the output impedance of the source is high enough and the total capacitance of the cable connected to it is high enough, yeah, you might start to get some HF roll off. But the output impedance on the iPhono is less than 100 ohms. You'd need to be using more than 500 meters of 120 pF/meter cable to get the high frequency cut of point of that circuit close to the upper frequency of human hearing, not to mention, as @toddrhodes notes above, the .6 meters of one cable and full meter of the other basically have the same total capacitance, and with that output impedance you're talking about a cutoff frequency from capacitance up in the radio wavelength range.

I don't know what's causing the sonic differences you're hearing -- as a matter of science we doing really know how to correlate some of the things we hear when it comes to cables with what we measure, and there are probably other variables like different geometry or different conductors -- but whatever is causing the difference, it's probably not total cable capacitance.

 

Thanks for the explanations.

I did the same capacitance calculation later (obvious when you think about it!) on and realised the same-ness.

Puts it to perspective...

Thanks. Mystery continues hey. Looked in to it some more and it's a hazy minefield for sure: few ICs actually have any specs, let alone meaningful descriptions or wider consensus about what difference any of the designs and materials might make. Not to fan the cable flames but interesting to note.

Might just go for a longer QED.

Cheers.

 

With short line level interconnects between a low impedance source and a high impedance load -- an application where there "shouldn't" be significant differences between these various kinds of interconnects -- we have all kinds of different manufacturers of cable offering all kinds of different scientific or sometime pseudo scientific reasons for why one their cables sound different: cable geometry, conductor grain structure, constant of the dielectric, etc. -- and then we have our own pseudo scientific testing -- we switch between cables and listen but don't necessarily try to match volume identically or make sure the different cables are terminated identically. Then there are things that we personally may do that can't be explains -- like, I swear, damping the RCA connectors and the connection to the component with some kind of CLD material really improves image focus. Some of these things we can understand explain easily -- the role of cable capacitance in shaping the frequency response of a passive generator like a phono cart; the cable concerns with a high impedance source; the roll of low resistance shield and return cable in reducing AC leakage noise in single ended audio connections, etc. Some, not so much.

 

Nicely put.

It's one area I've chosen not to think too much about or indeed spend too much on as I can't help to view it all pretty skeptically tbh, especially the myriad unsubstantiated claims in the more expensive stuff. But, I'll never knock something without trying it; and indeed this has demonstrated to me they can make a difference at least in this application.

... But still not knowing why I've simply ordered a 1m QED to hopefully redress the tonal balance.

The CLD material connection-damping thing is totally new... will look it up.

 

Cables undoubtably have their own sonic footprint.
Silver cacles are brighter,
Probably measure differently also.
As, has been said on this thread.
Something's are inexplicable
Concerning sound quality.
DNM cables transformed my
System out of all proportion
Whether it would perform the same
Trick in someone else's system is
Hard to say.