Designacable for XLR interconnects?
- Thread starter clogman
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darrenyeats
pfm Member
FWIW flat to 20kHz is sufficient for analogue but I'd avoid star quad for digital interconnect. AIUI low capacitance is key for digital because of the high frequencies.
Also, in the pro world they'd say star quad is only for noisy environments. Only audiofools (like me) would think about them for home.
darrenyeats
pfm Member
Basic engineering and non-foo should be inexpensive IMO.
See Benchmark explaining about star quad (versus twisted pair): https://benchmarkmedia.com/blogs/ap...-the-importance-of-star-quad-microphone-cable. But they actually promote the Canare which I referred to earlier, not just for mic feeds but line level. In summary, shielding does nothing to stop EMI. For EMI, balanced twisted pair helps and star quad geometry helps further. Shielding helps with RFI.
As I mentioned I've not heard anything yet so this could be all smoke, for me anyway.
Basic engineering, yes.
Non-basic engineering will cost more.
Search out Bruno Putzeys document on cable design - I'm not in a position to find it ATM. The Grimm cable is one of his designs, hence the reason why I don't believe it to be foo but to be fully engineered.
Iirc the design principles are about symmetry, full screening, and microphonics.
As with all things, whether it delivers anything above an alternatively implemented cable is the unanswered question.
darrenyeats
pfm Member
Chris, now I think about it more, "basic engineering principles" doesn't necessarily mean "basic engineering". Fair enough.
misterdog
Not the canine kind
@ darrenyeats , many thanks for the informative link.
I think anyone who has an interest in audio should watch the included video, especially those who say that 'balanced' is only necessary in noisy studio/live environments.
Also an RCA cable has even less immunity than a 2core balanced cable..
https://vimeo.com/155057552
I think anyone who has an interest in audio should watch the included video, especially those who say that 'balanced' is only necessary in noisy studio/live environments.
Also an RCA cable has even less immunity than a 2core balanced cable..
https://vimeo.com/155057552
Cool - bit extreme to put transformers straight onto a mic cable, but get the point.
Never have any charger near my audio gear, but of course can't avoid mains and associated transformers and switching power supplies.
If only all manufacturers would have mains plugs at the same side, it would be so much easier to route signal and mains cables well away from each other...
Certainly makes the point for star quad if XLR cables are used - even if for higher voltage sources than mics.
Never have any charger near my audio gear, but of course can't avoid mains and associated transformers and switching power supplies.
If only all manufacturers would have mains plugs at the same side, it would be so much easier to route signal and mains cables well away from each other...
Certainly makes the point for star quad if XLR cables are used - even if for higher voltage sources than mics.
I have a very lazy equipment arrangement.
A mini PC and 2 other streaming devices (squeezebox and Chromecast) together with a few switch mode power supplies are scattered in among the audio equipment and by the signal cables.
A router, a hub (switch), a fibre modern, another mini PC and a dect base station are nearby. And to one side and slightly in front is a bench with a TV, another PC (media centre), another hub and an AV amp. This connects back into the hifi to use as the front speakers.
Why wouldn't I want as many of the interconnections as possible to be balanced?
A mini PC and 2 other streaming devices (squeezebox and Chromecast) together with a few switch mode power supplies are scattered in among the audio equipment and by the signal cables.
A router, a hub (switch), a fibre modern, another mini PC and a dect base station are nearby. And to one side and slightly in front is a bench with a TV, another PC (media centre), another hub and an AV amp. This connects back into the hifi to use as the front speakers.
Why wouldn't I want as many of the interconnections as possible to be balanced?
misterdog
Not the canine kind
Or in my case all of them, even the phono stage though a single ended design utilises XLR shielded interconnects. My phono to pre. is a 4.5M run, imagine how many £ 00 or 000 I would have spent on RCA cables obsessing over which may sound better.
4.5M XLR hand made for less than £ 30.
Interestingly I took my 'balanced' beliefs to the extent of buying a balanced mains transformer (it came up on the classifieds) so now I have 115 V on both live and neutral phases, with some interesting results. I have 17 mains transformers in my system, so had a slight background hum.
The balanced mains has reduced that to near zero and lowered the noise floor of the system.
4.5M XLR hand made for less than £ 30.
Interestingly I took my 'balanced' beliefs to the extent of buying a balanced mains transformer (it came up on the classifieds) so now I have 115 V on both live and neutral phases, with some interesting results. I have 17 mains transformers in my system, so had a slight background hum.
The balanced mains has reduced that to near zero and lowered the noise floor of the system.
Going back to the original query - whilst of course acknowledging all the great stuff that's been shared on this thread - 't plot thickens:
Arcam indicate that the hot and cold pins differ on their rHead compared to my DAC:
Wyred4Sound DAC-1: "standard Pin 2 hot configuration"
rHead: 1=GND, 2=cold, 3=hot
Question is: would this be expected to make a difference given that the differential signal is used? And could that explain my earlier observations of somewhat distant and rather aneamic sound compared to RCA?
Arcam indicate that the hot and cold pins differ on their rHead compared to my DAC:
Wyred4Sound DAC-1: "standard Pin 2 hot configuration"
rHead: 1=GND, 2=cold, 3=hot
Question is: would this be expected to make a difference given that the differential signal is used? And could that explain my earlier observations of somewhat distant and rather aneamic sound compared to RCA?
Julf
Facts are our friends
Only difference is a reverse absolute phase, but sound quality shouldn't be affected as long as both channels are the same.
adamdea
You are not a sound quality evaluation device
very fair point. FWIW I think that you may need balanced analogue connections to achieve real hi rez. See eg the difference between rca outputs and xlr of 5-10dBI have a very lazy equipment arrangement.
A mini PC and 2 other streaming devices (squeezebox and Chromecast) together with a few switch mode power supplies are scattered in among the audio equipment and by the signal cables.
A router, a hub (switch), a fibre modern, another mini PC and a dect base station are nearby. And to one side and slightly in front is a bench with a TV, another PC (media centre), another hub and an AV amp. This connects back into the hifi to use as the front speakers.
Why wouldn't I want as many of the interconnections as possible to be balanced?
http://archimago.blogspot.co.uk/2017/06/measurements-oppo-sonica-dac-ess-sabre.html
I also seem to remember that when xlr was used by Archimago in earlier tests apparent differences upstream have disappeared (IIRC using really crap digital cable which acted as an rfi transmitter)
Basically why wouldn't you?
Julf
Facts are our friends
Hmm, not sure about that - how do you define "real hi rez"?
Slightly more expensive connectors?
darrenyeats
pfm Member
Adam, with common gain structures, with XLR you effectively lose approx 6dB to the ether. This is because the line level signal tends to double (e.g. if RCA is 2VRMS the XLR is 4VRMS). You can use attenuators to compensate but then that impacts impedance relationship.
Neither the 6dB less dynamic range nor the impedance change is very significant, I know. And impedance is not a factor at all if you have a good active preamp. But you asked "why wouldn't you?" and that is a TECHNICAL answer, for DAC-pre use case. Justified or not, it's a fact that SOTA last 6dB of SNR *with* naturally low output level *with* that "proper preamp-like" low output impedance *via XLR* - getting all that simultanously, off the shelf, is still actually very expensive in DAC-land (I can only think of Weiss and dCS that do it all).
PRACTICALLY any potential downside is not important - plus sometimes more digital attenuation sounds better (I'm not sure why). I'd still always choose balanced connections myself, because of noise rejection.
Neither the 6dB less dynamic range nor the impedance change is very significant, I know. And impedance is not a factor at all if you have a good active preamp. But you asked "why wouldn't you?" and that is a TECHNICAL answer, for DAC-pre use case. Justified or not, it's a fact that SOTA last 6dB of SNR *with* naturally low output level *with* that "proper preamp-like" low output impedance *via XLR* - getting all that simultanously, off the shelf, is still actually very expensive in DAC-land (I can only think of Weiss and dCS that do it all).
PRACTICALLY any potential downside is not important - plus sometimes more digital attenuation sounds better (I'm not sure why). I'd still always choose balanced connections myself, because of noise rejection.
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Julf
Facts are our friends
That is of course assuming the input sensitivity is the same on the RCA and XLR inputs. Often amp manufacturers compensate for the level difference, so that there is no difference in SNR.
As I keep pointing out, you get most of the benefits (especially the common mode rejection ratio and avoidance of ground loops) even without a balanced output on the source, as long as the input stage of the amp is differential and the cable is balanced.
Hi all,
Latest news on developments relating to the original question.
It turns out that the switch to change between XLR and RCA input is the culprit, as things slowly improved upon repeated switch-flicking at the suggestion of a very helpful customer Services guy at Arcam.
Did a thorough comparison yesterday and found a basic Atlas XLR cable of a few years old (star quad with Neutriks) now works fine - in my comparison pretty much on a par with an Atlas Mavros RCA cable of similar age. Swapping for an Ascent XLR cable did not alter things much. On balance I just about preferred the XLR input (I think - very close) so bought the more basic Atlas cable when offered at a good discount.
Probably should have tried the Designacable first instead given lack of difference between cables, but the discount was good and I just want to go on and enjoy listening to my new kit!
Saying that, Darrenyates I would love to hear the outcome of your comparison!
As for XLR better than RCA: perhaps just a little for my case, using my kit and my ears.
Which I find rather surprising given the modest price point of an Arcam rHead - how did they manage to include XLR and RCA for 399 squids - and then drop the price to £200 - and still make a profit???
Latest news on developments relating to the original question.
It turns out that the switch to change between XLR and RCA input is the culprit, as things slowly improved upon repeated switch-flicking at the suggestion of a very helpful customer Services guy at Arcam.
Did a thorough comparison yesterday and found a basic Atlas XLR cable of a few years old (star quad with Neutriks) now works fine - in my comparison pretty much on a par with an Atlas Mavros RCA cable of similar age. Swapping for an Ascent XLR cable did not alter things much. On balance I just about preferred the XLR input (I think - very close) so bought the more basic Atlas cable when offered at a good discount.
Probably should have tried the Designacable first instead given lack of difference between cables, but the discount was good and I just want to go on and enjoy listening to my new kit!
Saying that, Darrenyates I would love to hear the outcome of your comparison!
As for XLR better than RCA: perhaps just a little for my case, using my kit and my ears.
Which I find rather surprising given the modest price point of an Arcam rHead - how did they manage to include XLR and RCA for 399 squids - and then drop the price to £200 - and still make a profit???
darrenyeats
pfm Member
Will keep you apprised, they should arrive Tuesday.
Julf
Facts are our friends
The major part of the extra cost would be the connectors - I doubt the manufacturer pays more than £5 for them.
Cereal Killer
432
Yes bought from them many times, ran my Resonessence MIRUS/ATC etc type systems with their cables a few years back. Good build and materials, good service and prices. Nothing to not like about the place.