Long RCA interconnects

I need a pretty long run of RCA interconnects to connect my phono preamp to my integrated. About 18 feet long.  What are some options under $400? 
18’ of single ended interconnects is a recipe for terrible hum and noise problems. 6’ is the practical maximum length for a single ended run. Do you have the option of running balanced cable?
You'll want to make a very short run to your phono preamp, and make the long run from that to your integrated.

As @folkfreak says, balanced is best.
Yes, the phono run is short, but the run to integrated has to be long and since both devices are single ended, it can't be balanced, unfortunately.  I'm hoping a shielded cable will hopefully reject interference.
You might be lucky. I used to have a 30’ run single ended from my preamp to mono blocks. With it running below the floor in the crawl space I used to have no issues. I then moved temporarily to a rental and had to run it on the floor and it was unacceptably noisy so I had to switch to balanced which I’ve been with ever since.  You also want to make sure the output stage of your phono stage is up to driving a long cable (as cable LCR will increase with length) - what stage are you using? 
Eastern Electric Minimax phono stage.
I recommend Blue Jeans cable LC-1. Shielded. Low capacitance. Affordable. I have several long runs. No loss of highs. No hum. No noise of any kind. Money back guarantee. 
Try running the AC lines from the same spot as the pre or amp, to reduce potential for hum. Ie, the same ground potential would be the result of the AC is from the same exact receptacle.

If you get some hum, try the ’same AC origin point’ trick. Play with the AC to try and reduce hum, is the deal.

We've made 6.5-7M RCA cables for people -- totally unshielded btw. No hum. That's a $35k pair of cables. Better hope there's no hum.....
Wow that’s a low gain phono stage (42dB/57dB) - so you could be in for some issues if you’re driving a long run off it. The stage itself is capable of driving a healthy 2-20V output but it would be good to know what’s coming in, what cartridge do you have? Hopefully MM or high output MC
I have a Benz Micro Silver MC
OK that's a healthy 2mV output so the phono stage will be outputting 1.4V which is a good signal and should put you in as good a situation as you could hope to drive that long single ended run. If you had a .3mV output (i.e. typical low output MC) things might be more problematic -- anyway good luck!
Don't know of options but 18 feet is very bad news sonically.Good luck though.
Just got in a pair of Kabeldirekt 20 feet pair to test out. Sounds amazing. Just for peace of mind I'll probably end up making my own 'audiophile' interconnects but cool...and it looks like I really need 15 feet or so.
So eventually ended up making my own interconnects....12.5 feet length is actually sufficient, I overestimated the initial length.  Went with DH Labs Silver Sonic II cable and KLE Copper RCAs...total parts cost $200...all silver plated wires to interconnects...sounded fantastic at initial listen.  Not a cable believer at all, Pink Floyd's 'The Wall' never sounded better through vinyl though...but who knows, may be the $20 Kabeldirekt sounds the same as well, I just can't be bothered to test. Wanted to make a shielded silver cable and here we are.  Highly recommended. If I wanted to buy it, it'd probably cost $800 - $1200, you figure $200 (parts) + $400 (labor) + $600 (marketing + other overheads) = $1200.
Triple that number if you want to actually have a business that lasts longer than the initial musing.

The number that is openly stated by synergistic, in the TAS published cable bible section of an industry overview with many interviews with company owners... (pdf), is 9x over raw cost calculations, in the cable world.

The audio business is hard. Not straightforward - not like it seems .... from a safe distance. But hard. Very hard.

There is a lot of the moat problem that is recently being buzzed about, in this candy/moat concerned war of words between Elon Musk and Warren buffet.


The moat problem, something created by established players. they protect their Territory via territory denial via natural advantage coupled by sometimes (ok, almost always) very nasty behaviour... and the rest of their business connectivity is risk aversion oriented and plays it safe, as that is human nature.

It’s a human nature thing and is even deeply embedded into the sciences:

"How success breeds success in the sciences" (whether it is deserved, or correct... or not)


"To those who have, more will be given"

The term "Matthew effect" was coined by sociologist Robert Merton in the 1960s to describe how eminent scientists get more recognition for their work than less-well-known researchers—the reference is to the New Testament parable that, to those who have, more will be given. Previous attempts to study this phenomenon have yielded inconclusive results, in part because it is hard to prove that differences in achievement don’t reflect differences in work quality.

To get around the quality question, De Vaan and his co-authors took advantage of special features of the main science funding organization in the Netherlands, IRIS, which awards grants based on a point system. Everyone whose application scores above the point threshold gets money, while everyone below is left out. The authors zeroed in on researchers who came in just above and just below the funding threshold, assuming that, for practical purposes, their applications were equal in quality.

First off, they found the benefits of winning an early-career grant were enormous. Recent PhDs who scored just above the funding threshold later received more than twice as much research money as their counterparts who scored immediately below the threshold. The winners also had a 47 percent greater chance of eventually landing a full professorship. "Even though the differences between individuals were virtually zero, over time a giant gap in success became evident," De Vaan notes.

Part of the message in business, in order to have wide term success, some part of your plan and acts have to center around the psychology of sociopathology, psychopathology...... as the competition for market share involves that mentality, to some notable degree (extreme to fair in level) in all the extant players.

Which, for a reasonable human, when found to be, feels quite unsettling and sickminded. We find this effect everywhere, most notably (seemingly) in the corporate and political worlds. Which, of course, as birds of a feather, will begin to flock together...

they'll run the gamut, like SpaceX having what is now noted to be high levels of natural advantage, all the way over to extreme expressions of embedded pathological aspects being the main provider of a moat, as the product cannot compete in an open world..ie..Monsanto.

The longer a market is around (a given area of technology, etc) the more likely is is to have drifted from natural advantage being the driving force...into pathology and psychosis being the main component of market share attempts/control.

And politics is a very old thing. We note it is built almost completely out of pathology and psychosis.
Definitely, I did go to business school. That's basically barrier to entry - that's why you wouldn't see everyone making airplanes for instance, or anyone making computer operating systems. A few core companies have the market.