Using 2 different brands of interconnects?

^^^
from the man who asked

I now have a low level buzzing coming out of my tweeters even when i am in mute. It happens even with the amp on and preamp off never had this before. Any suggestions would be great. Thanks in advance. [in  Low level buzzing coming from tweeters. | Audiogon Discussion Forum]

and then said

Got balanced cables as i now have a balanced preamp Purist made my single ended cables balanced buzzing is now gone. I will now used balanced always and use Purist always. Thanks!!!!

Reading between the lines, one could conclude ebm is not an engineer...

OP, Yes, you can intermix and I’ve concluded the change and benefit realized is less noticeable with cables in the $100 range as you’ve noted. I’ve tested a lot of interconnects past 25yrs as a geek / nerd / hobby.

Works well with Higher End Cables Too:
Now re-testing again with a full loom of Cardas (older signature Golden Reference) and full loom of Analysis Plus (OCC Crystal), while liking both brands for different reasons with the same brand end-to-end, I’m now going back and intermixing the two brands/models and noticing intriguing sound results with sort of a "hybrid" tone and texture. Thus, maintaining some of the plushness and tone of the CGR cables and speed and clarity of the AP OCC Crystals. The source cable tends to dictate the leading tone and texture vs. the cable between the preamplifier to amplifier. Can produce different results swapping source and preamp too for more or less of a plush or more clear sound.

Having tried it several times in all combinations, I’m not a firm believer that you must run the same brand/type cable end-to-end in a system. In some cases it can be worse or too much of one type of sound. All Salt -or- all Pepper (no), Salt -and- Pepper, both (yes) please.

Thanks, decooney. I really appreciate your feedback, along with everyone else’s, too. You have to be in a certain position in life to be able to experiment freely with cables, especially high end cables, and this is not my circumstance.
I took the first step and replaced the super cheapo cable from my DAC to my integrated and the results are drastically better. Clearly, that was a very good decision. Onward to the next steps.

@m669326 I have to blame a close friend who loaned me a TOTL pair of interconnects once 20+ years ago, they were $100 more cost (used/demo) than the special edition CD player I had at the time. Yes, more $ than the CD player itself.  Once I heard the difference, I could not afford it but could not deny the difference. Had those cables for 20yrs, and sold them for what I paid for them to a Pass Labs amp owner, and should have kept them. The OCD obsession started there, to a ridiculous degree I'll admit. Would have never believed it myself had I not tried it.   

Really-really good interconnects can tend to hold a high % of value if you select well and keep them in really good condition with papers, certs, boxes. Some new-version interconnects are not always better than their prior versions depending on what sound you are looking for.