(20 year old) 1.0 meter Kimber hero xlr and Audioquest diamondback xlr cables

I would suspect and seen oxydation under the dielectric ,over time it too can get brittle ,especially being that old. Newer products have coatings on the metal and 

dielectric application is bonded far better .

plus your connectors are low quality gold over brass which is 3 x more noise,resistance then qualityGold copper , time for a serious loom upgrade 

same applies to power cords , go to Audio Art ,his fair priced plus power cords have Gold copper Furutech connectors , good connectors eliminate bottlenecks 

and many times over looked evern mfg speakers ,considering you can get at dealer cost Evo WBT connectors for under $100 for4 , and internally cheap Xovers over 70% of manufacturers still do this practice at the expense of the sonics ,Why ? To save $$ I have been rebuilding Xovers or upgrading them for years . I use copper on every connector it sounds so much better ,more natural.

I used to own a few pairs of Kimber Kable Hero HB that I really liked. The difference between the HB and the ordinary Hero is that the signal supply cable is made of pure silver instead of copper. That changes the sound significantly, perhaps in the way you are looking for. But as said by somebody else, trial and error is the only way for you to find out. Unfortunately, the HB version of these great cables is quite rare on the used market. I sold mine recently with a pinch in the heart as my new system only has single ended terminals.

Good luck !

If you've got Accuphase, don't cheap out on the IC; beg borrow or steal a few different (hopefully already broken in) and experiment.  Your ears are used to the Heros, but don't let that "comfort level" stop you from trying something else.

@duketbrd88 

good questions. I had a somewhat similar experience. I had been using some new Cardas xlr cables between my DAC and preamp and decided to audition some different ones at the recommendation of my local dealer. I tried them in my system and couldn’t believe the difference in sound. More difference for me than even speaker cables (of high quality) and i hear those differences easily. So, I think you’re correct to explore options that will give you what you’re looking for - I suspect you’ll find it.

And, i think you’re also correct asking for experiences here to help expedite the process. While there’s no substitute for trying things yourself, there are far too many options out there to try them all. So a little guidance from others here is helpful. Sorry I can’t be one of those to help as I’m not familiar enough with options in your budget. But it’s well worth the exploration.

Best,

Want to surprise yourself again?

Buy the DeOxit/De/Oxit Gold contact cleaner kit (Amazon has it) and clean your old Kimbers and clean the connector on your Accuphase and your PS Audio DAC.  The kit has the little tools that fit inside XLRs.

The sound will change again.  You may like it better.  I clean all my terminals and connectors every 6 months and it always improves the sound.