AudioQuest vs Cardas XLR

@jeffreyw  Well, having myself KEF Reference 3s with AQ power cords and having tried many combinations during the last 12 months, I would recommend you to go in the direction of pure silver or silver alloy (and not silver-plated) cables both for speaker and interconnects. 
The KEFs have amazing weight and physicality across the frequency range, but struggle to sound really « free » and unconstrained dynamically. Using silver-based cables really enables the speakers to shine. With the KEFs and the Mac amplification, I would tend to look away from Cardas, although I have no experience with the Beyond XLs which I hear are amazing. If you were to go the Audioquest route, I would go directly to the Firebirds then to get the PSS solid silver core. 
Personally, I preferred going outside of Audioquest because you get silver only starting almost at the top of their range, which would have meant it was beyond what I find still reasonable to spend for cables. Shunyata was a good match personally on my system but not everyone’s cup of tea (mix of solid OCC silver and copper tubes. Siltech was amazing as well. I read excellent things about Kimber’s silver cables but again, only available for their top-tier cables.

my 2 cents, YMMV

@jeffreyw The funny thing, many have steered me away from the Cardas/McIntosh synergy, considering my wishes to liven up the highs.

@jeffreyw Its a final tuning and balancing act. Similar to how each of the different McIntosh amplifiers exhibit a slightly different type of sound and presentation, and so do different type/design cables you are currently using and looking at now. As a former owner and tester of various AQ, Cardas, Analysis Plus, I’d venture to suggest two focus areas - if you must change cables first. Your particular and much older OFC AP copper Oval 9 speaker cables and more recent OFC Mogami Gold interconnects are [both] not allowing the higher tip top frequency to come through for your Kef Ref 1 Metas, imo. Your current cables can even be weighty, plump in midrange imo, overcasting the highs some. Taketh away. a And, if you pick older Cardas design (pre-Clear) line cables instead of something like latest Clear or Clear Beyond in Cardas, change w/b minimal, likely not what you want. I’d go after your speaker cables first, then ICs next. You can squeak out more detail for sure. I’ll go out on limb here and will get blasted by nimrod cable-nay-sayers, and don’t care...fwiw. When the chime in, ask specifically what they’ve tried, first hand.

Demos: #1 If I were in your shoes, given your current investment in amps and such, find a local dealer who can loan you cables to try, best bet. This is how I discovered the right AP/Crystal or Cardas/Clear or Apature/Silver over copper in prior systems. The std older generic OFC can sound "weighty" and lacking highs in some brands and designs. #2 With no local dealers, TheCableCo loaner-buy program or #3, TMRAudio or MusicDirect [check] with a return policy helps add some demo-trials and helps take some guess out. DM me, got contacts for you.

Cardas: Tip: i.e. knowing the rich Mcintosh sound in some of the pres/amps, you could probably stand [for example] to move away from your older std OFC stuff with your current speaker cables/interconnects up to really good Crystal/OCC or Silver over copper, or current generation Cygnus or new Clear line with Cardas. These can be more neutral though, heads up if you are a bass head. If you wanna cheat on price with Cardas avoiding Clear Beyond, call them and ask for Brian or Josh. Be sure to ask about 4-wire "Cygnus". I’ve done some factory demo’ing with them, and given feedback over the years. Right now I’m testing and comparing Cardas Clear Reflection vs. Cygnus in my own rig - testing with different sources. Cygnus allows more detail/highs to come through at my sources. More neutral, but nice tip-top-highs come in. If I want more richness, I flip it, putting Clear Reflection at the Source, and putting the Cygnus between the preamp and amps. It’s a fun way to have both options, simply swapping source, preamp and amp cables.

Clear Reflection has detail yet can be a tad more weighty presentation than Cygnus or standard "Clear", still available too. Clear Reflection has some golden tone, split with old/new Cardas clear designs You may not want this result in your Mc rig, I sense you have some of that now with your older gen OFC 9 Blk/Yellow speaker cables, and current "gold" Mogami ICs.  Cardas Clear ReFLECTION (not talking Clear Reference) detail comes through slightly yet not as evident as it is with more neutral 4-wire Cygnus. imo, if you must have Cardas, and must save, Cygnus can be the budget sleeper cable. Now, Is it top-top clear level, um, partially, sort of like 80% maybe closer, but not like Clear/Beyond. People resale std "Clear" some times because it’s more neutral, watch out what you ask for. Opinions will vary with other people’s systems. It’s weird, Cygnus requires a very long time of settling, relaxing, and so called burn in though, I tried them twice over 2 years. Retried again later and discovered something new. Realized I did not give them enough time first go-around. Much better after 30-45 days. Glad I retried them.

AP: For a jump in Analysis Plus, a move up to Silver Apex w/your speaker cables and Interconnects will allow missing detail to come in. Can be smooth with detail. Just like Cardas, each cable type up/down the line with Analysis Plus cables will have different results.

Guidance - Ignore the cable-naysayers who’ve never tried any of this or have not compared with a system like yours. Their default is Mogami. Good for them. If all else fails to help, just do demos, this is the best way, and give yourself time. AQ: no further comment, been there done that - nice but simply prefer Cardas design, connectors, and overall quality. A preference thing. Nordost fans can guide you there, for Uber-detail cables if that’s what you want. Best of Luck

I concur with @decooney you might want to test out some speaker + interconnect looms before settling on a very nice interconnect. Nothing beats experience and trying out different metals and geometries across brands might give you some significant hints on which direction is good for you.

@decooney 

@habermas 

Thank you for that insight; very informative!

Cardas clear beyond works great with my McIntosh system. You can justify Audioquest however you want but Cardas clearly says Made in USA down the entire length of the cable. My dealer was really pissed Audioquest is outsourcing more to China. That is not the values I want when I’m spending big money.