Need 25 foot interconnects

Using an XLR connection would be of no particular benefit unless both the pre-amp and amp were balanced. Just use I/Cs with regular RCA connectors. 

I use mogami 25 foot IC's and I think the RCA cables would be better in your setup.

I would get Mogami Neglex star quad and some ProFi ends.
You‘ ll be way better off with the MBs at the speaker.

However it is probably best to use that Neglex (or Cardis, Canare, etc) star-quad and fit it with XLRs. Then back at the monoblocks use something like these:

One could start with the XLR cables and use the XLR to RCA adaptors. Neutrik catalog numbers for the more common XLR to female RCA jacks are NA2MPMF (male XLR) and NA2FPMF (female XLT). Better check.
Then if there was no hum you are done. And if there is hum, then look at the isolators like the Jensen??

I usually DIY my own using the Neglex 2534 star quad, in brown to match wood floor colour. All the star-quad design is good stuff… e.x. Canare.

@holmz ,

+1

The best reason to use XLR is that they are less prone to introducing cable artifacts -sound qualities of the cable.

The Jensen are about the best out there and cost only a couple hundred bucks for a pair.

Bob

I have 26' AQ water xlr's I was using and now I need shorter ones. So make sure your gonna keep your gear like this before investing in them! 

@holmz  thanks for that advice.  I also read that Cardas makes an XLR to RCA adapter that I can order with the ground pin floated. Would that do the same thing as the Jensen? Or would I just lose the value of the balanced cable by floating the ground at one end?

with the Jensen, I’m assuming I’d run a long balanced cable out of preamp and then a short IC from Jensen to amp.  Thanks.

I'm running 20' RCA cables and it didn't make a difference in sound when I used a 3' RCA cable, I compared them in the same room with the same equipment. I'm not saying your balanced output may not sound better, but I don't think that going from 15' to 25' with RCA is going to make any difference, unless you are picking up noise on your RCA cables.

I dunno @nymarty - I would do the XLRs either yourself or from some place like BlueJeans with a star quad shielded wire and the XLRs.

Then just use the Neutrix to XLR jobs which are $10-$15 each.
If there is not hum you are done. And if there is hum then try the Jensen’s isolator.

That is assuming that the Cardas is the same as a Neutrik in that it adapts and is not a balanced isolator.(???) so the Cardas should be the same?? 

Basically it’s a couple of baby steps.

• Cable+adapter and no hum = job done.
• Still noise(?), then slip in the isolator.

Would that do the same thing as the Jensen? Or would I just lose the value of the balanced cable by floating the ground at one end?

Yep you lose the balanced with the floating ground

• The adaptor gets the signal to the amp.
• The balanced cable allows you to go to the isolator if there is hum.
• So you can use the isolator later if needed, or if you change to mono blocks that have a balanced input, then you already have the XLR cable.

I would do that before going to a high $ single ended cable, as it has a much higher probability of mitigating hum and noise… having Star-quad balanced + shield + isolator is close to bullet proof.
Not quite as good as a balanced amp, but as close as one can get.

I'm running 20' RCA cables and it didn't make a difference in sound when I used a 3' RCA cable, I compared them in the same room with the same equipment. I'm not saying your balanced output may not sound better, but I don't think that going from 15' to 25' with RCA is going to make any difference, unless you are picking up noise on your RCA cables.

^Entirely likely as well.^
Which is why I first mentioned the star-quad with the ProFi ends.
And coax is also an option.

If that doesn’t work, then desolder and go to balanced.
But he stuff is only $1/ft or less so it is probably just cheaper to order it if doesn’t have a soldering iron.

Maybe you could try one amp (then the other) using an RCA double end male to hook your two shorter cables together…??
If that works with no humming, then just order the right length with RCAs.

I have been presented with this issue a number of times. You are doing a split in the right place. I have done both RCA and XLR. I would recommend the highest quality of RCA you can afford. I know this is painful. I do not recommend adding any converters. Native single ended is very very likely to sound the best, certainly at 25’.

Your system is going to sound much better getting the chest out from in between your speakers. I suspect if you hang a really thick rug below the windows, that will greatly improve imaging. Tube traps in the corners would probably also significantly improve the sound. An area rug in front of speakers until nearly your listening chair. Little corner traps (cheap and innocuous.

Also, this gives you the option of using super short speaker cables… this is reported to me by some folks I really respect to slow a really big jump in performance. You have to use a really short, high quality speaker cable… 1.5’ or maybe two feet. It is supposed to really improve the presence of the system. Something I have wanted to try, but never have been able to.

Mogami XLR cable is about as inexpensive as you can get, and still get decent quality. Probably cheaper than a lot of RCA cabling.

B

You need balanced amps to make any difference with balanced cables. Necessity is determined by RF noise in your playback space and sensitivity to it of your electronics.

You need balanced amps to make any difference with balanced cables. Necessity is determined by RF noise in your playback space and sensitivity to it of your electronics.

100% totally agree. Those 25' length RCA cables are going to make great RFI & EMI receiving antennas. My rule of thumb is 3' or less when it comes to RCA cable lengths. 

My advice:  Try the unbalanced with cheap RCA cables first.  if the noise is acceptable then you can upgrade.  If on the other hand it's a noisy mess, you are going to have to find something better.

If long interconnects needed for sure XLR ,that’s what all recording studios 

use for lowest possible noise .

first, balance to an adapter means..... unbalanced. Total waste of time, effort and money draw it out for yourself and see.

Second. Your plan is fundamentally good. Bigger differences in speaker cable due to the currents involved. Want an explanation - search for the club preso fromt he Belden engineer who does Blue jeans cables. He does a great job so why would i waste 10,000 words duplicating it? :-)

Pick a good interconnect with modest capacitance and decent shielding. For home environments most are fine. Quality of cables (dieletric, etc) of course always matters, and 30’ means it matters more.

G

ps: some posts above advocating XLR. 1) XLR is a plug not a transport topology although it ought to mean balanced. If you use XLR to an adapter its nothing more than excess metal. 2) they maybe didn’t read your post indicating you cannot accept a true balanced input. 3) if they did read it they have no idea what they are typing about.

Quick tutorial: Balance has little to do with the plugs, but the de facto standard is XLR.  Balanced means tow mirror image signals that deferentially sum (one +, one -) to the input. This means that they are relatively immune to interference since if a magnetic wave passes through it adds to both sides, and they are subtracted, so it cancels. Its that simple.  Balanced means immunity in a very noisy environment.  So, is your living room noisy (magnetically) in the audio band? if so, move the refrigerator out!  Its really not a big deal unless you are experiencing some kind of hum or noise.

Now let's get more detailed.  90%+ of all banced inputs and putputs are total bullshit.  Yes, they cancel noise. But they are typically implemented with an additional stage of electronics on top of the normal signal path, This flies int he face of purist design.  Worse, some (most?) of those use an op amp.  QED. So you are often much better off using the regular RCA out unless the circuit is inherently differential/balanced (as in the case of most of my preamp and power amp front-end designs). And even given that,  -- where i have a selfish reason to push it -- i don't necessarily advocate using it unless you have a demonstrated need.

really good unbalanced interconnect.  WBT or similar on good, shielded twister pair cables.  Move on.

@erik_squires 

This is exactly what I would do in his situation, balanced might be better if you have tons of noise from other equipment like recording studios do, but in the home environment it's unlikely, though it does happen every once and a while.

+1 for Erik's suggestion.  Probably not a noise problem in the listening room.

They sell a Rolls MB15b ProMatch that converts from rca to xlr nicely done.

This makes a decent  interconnect.  They choose the gold or rhodium ends

https://www.partsconnexion.com/FTECH-88758.html

These are exceptional  but the gold ones that are half the money are really decent  as well. These are really silent 

You’re getting some bad advice here.  As one respondent correctly said, unless the amp and preamp are both fully balanced, XLR’s do you no good.

For DIY, I recommend NeoTech NEMOI 3220.  Single crystal. OFC.  Can’t be beat at the price.  Not cheap but cheaper than finished cables of that quality.
 

Cables are VERY important if you’ve got anything better than entry level equipment.  Put some quality RCA’s on them and you’ll thank yourself later.

If you were starting wtih a preamp with differentially driven outputs, and an amp with differential inputs starting with XLR cables would make sense.

I use the term "differential" to mean the + and - terminals carry equal and opposite voltages. Some preamps or amps have fake XLRs.

Anyway, lacking this, the RCA to XLR conversion is an opportunity to introduce noise and distortion in the line, so best to be avoided if possible.

@dougthebiker 

That's not entirely true you don't need differentially balanced equipment to have balanced outputs and inputs, it can be single ended inside the circuit in the equipment and you can still have balanced inputs and outputs, there are a few different ways to do it a transformer is one way.

My friend bought long ic from Morrow audio, they costumize with your request according to my friend. Check they might have some sale.

The amp and preamp do not have to be fully balanced to get benefit from XLR cables. While it is true that the simple adaptors that convert XLR to RCA are pretty much worthless, the device linked by @holmz is not a simple adapter. This box includes a transformer which is as effective (if not more so) at eliminating common mode noise as a differential input. 

An RCA connection relies on the ground connection for the return current. This connection method was originally developed to connect subsystems in a single console system, where all subsystems were powered by the same connection to the wall outlet. Whenever the components that are connected do not share the same AC connection, you have the potential for a ground loop. 

Well designed components minimize this problem by using a combination of diode bridge and resistor between the analog ground and safety ground, but, by necessity, there is still the potential of current flow between these two grounds. 

The interconnect and AC connections form a loop. Any electromagnetic waves that are "captured" by this loop will cause a current flow through the loop. The larger the loop, the more this will occur. If the two components are plugged into different AC circuits, the loop can be quite large. 

Ground loops doesn't just mean hum (although AC mains radiation is usually the strongest contributor). 

The Pro audio industry recognized this problem and adopted balanced connections as the solution. A balanced connection does not rely on a common ground connection between components, so it's possible to use very long cables without the risk of ground loops. 

If the preamp XLR connections aren't actually balanced, then using a transformer won't do anything. But most preamps that have XLR outputs will at least use an opamp to create the negative phase signal. 

Obviously adding additional circuitry (including the transformer) has it's own disadvantages. So I wouldn't recommend this for a short connection. But long connections such as the OP is proposing will probably benefit. 

The connection between the Jensen box and the monoblocks should be kept as short as possible, but these boxes will provide most, if not all, the benefit of having a balanced input on the amp. 

I am using a Jensen transformers on the inputs of my DIY 300B SET monoblocks with XLR connections similar length to what the OP is proposing, and they sound fabulous. I also have a pair of Pass XA60.8 monoblocks, and to me and several audiophile friends, the 300B monoblocks with Jensen transformers sound better. So I think these transformers are quite good and don't do much to degrade the sound. 

Thanks, all.  It sounds like the consensus is to stick with single-ended RCA cables of good quality and with good shielding. I’ve had no issue with the 15’ RCA cables I’m using now and they were fairly inexpensive. No hum, no noise.  Open to any suggestions on where to get the best cable at that length at a good price.  Will try Blue Jeans Cable but wondering if there are other companies that can do that length. I suppose I can also try DIY.

The trade off requiring long IC so far has been worth it. Getting everything off the front wall except for the speakers and corner bass traps has been a big positive.  Soundstage is deeper and wider and whole system sounds better.  Everything is just a little better placed in the music now.  

Belden? what kind of cheap monoblocks do you have to use that crappy cable? if you're going to use interconnects at least get the best, OCC single Crystal copper far superior to anything ofc on the market.

How about keeping your existing cables, but get a couple of AudioQuest (or similar) RCA female/female connector and then get a couple more RCA interconnects at 10 feet or so.  Then join them all together and you’ve got 25 feet. This gives you the flexibility if you ever need shorter ones again you can just take that apart and keep the interconnects for another purpose.

I would recommend a good cable company. My minimum is DHLabs. I have tried Blue Jeans and Belkin and found them to be equivalent to the quality that you get in boxes with inexpensive and mid-fi products.

Spoke too soon about no hum.  It got really quiet in the house tonight and had a good listening session and left the earlier comment where I said "No hum. No noise."  When I stopped playing music and stood up, I heard a slight hum.  I got closer to the speakers and they just have a monotone hum coming out of them.  Going to need to troubleshoot the hum this week and figure out the cause.  Lots of things going on that are different -- also switched from low level subwoofer connection (interconnect) to high level coming off the speaker binding posts, so not sure if it's the 15' interconnect or the high level subwoofer connect that is causing the hum.  Maybe the hum is making the soundstage better.  ;-)

+1 @ghdprentice . In my den I have a pair of Kef R11 being driven by PS Audio M700 monoblocks.  I took a pair of Audio Quest Rocket 44 cables cut them in half and am biwireing. The bass has improved so much I have turned off the sub. Big improvement over 8ft runs. I would also use RCA and an adapter to another pair of equivalent RCA of 10ft. Try to keep them clear of other cables. If it sounds good then spend the coin for a better pair.

As others have mentioned, the starquad configuration is best for a noisy environment. Canare L-4E6S is the very best because the shielding is the best: heavy, braided, pig to work with. Mogami is almost as good, but the shielding is twisted, so not quite as effective, but a whole lot easier to work with.

Add some decent connectors like ETI or KLE and you can't do much better. Switchcraft is pretty good too, for that matter, at bargain prices.

Belden? what kind of cheap monoblocks do you have to use that crappy cable?

Nice gear shaming @urbie -  however solid gold cable also seem to obey the laws of physics.

Spoke too soon about no hum.  It got really quiet in the house tonight and had a good listening session and left the earlier comment where I said "No hum. No noise."  When I stopped playing music and stood up, I heard a slight hum.  I got closer to the speakers and they just have a monotone hum coming out of them.  Going to need to troubleshoot the hum this week and figure out the cause.  Lots of things going on that are different -- also switched from low level subwoofer connection (interconnect) to high level coming off the speaker binding posts, so not sure if it's the 15' interconnect or the high level subwoofer connect that is causing the hum.  Maybe the hum is making the soundstage better.  ;-)

This is great.
Great to find this out now.

Is it easy to run an extension cord to the mono block?
That “test” could allow us to determine if the monos are on a different circuit.
Or you can flip breakers to work it out.

Your trouble shooting plan sounds good.

I will be transitioning my setup at some point next year and face a similar question. I’m currently using a long(ish) pair of WyWires platinum IC’s (13’ single ended) but will need at least a 30’ run in the new setup. The rest of my system is (mostly) connected up with Empirical Design IC’s and PC’s which I have used for decades and never felt the need to upgrade. I reached out to Karl last week to discuss and am confident he has a solution for my new configuration. ED cables tend to fly under the radar but recently won another Editors Choice award from TAS after doing the same in back to back years (2008 & 2009 I believe) FWIW. These are very high quality cables that are reasonably priced and therefore a great choice when you need a long run that could otherwise break the bank (the WyWires are great but considerably more money). Give them a call—Karl has been a trusted adviser for me over the years and is great to work with, customizing lengths, assessing system hiccups, etc.

Hum is more frequently a grounding issue than noise picked up by shielded interconnects in my experience.

A quick test is to float the ground on your components, particularly the amps, and see if it goes away.  If it does, it’s not your interconnects.

Just use ungrounded adapter plugs or pull the ground pins temporarily.

@nymarty 

 Will try Blue Jeans Cable but wondering if there are other companies that can do that length. I suppose I can also try DIY.

I have purchased all of my Canare L-4E6S RCA interconnects from Redco.  Just order what you want on their online order system and wait a few weeks for the build.  Very reasonably priced and high-quality workmanship (I know, it's just an interconnect).

The NeoTech I referenced above is Ohno Continuous Cast, single crystal copper.  Far superior to Mogami and Canare - I’ve tried both - and MUCH better SQ than Blue Jeans.

@dougthebiker for the win on solving the hum.  Thanks!  One of my amps - Schiit Vidar - was in the system after swapping out the monoblocks. When I disconnected everything from the amp except speakers and power, there was still that hum.  Couldn’t find my cheater plug to float the ground so switched back to the Belles Aria Monoblocks, which I just bought.   No hum at all. Dead quiet. Plugged in the 15’ interconnects from Schiit Freya + and still silent. Music sounds great!  Success!  
Thanks, all, for the recommendations on interconnects. Moving up to 25’ and just have to pick the right one for budget and SQ. 

… so switched back to the Belles Aria Monoblocks, which I just bought.

The gear shaming is getting a bit difficult.

@holmz  I was able to try your original suggestion.  I was on Emotiva’s website to buy a 12V trigger and they had XLR to RCA adapters, so I bought 2 of them.  I hooked up a pair of 20’ balanced XLR cables to my preamp, added the adapter just before my amps and connected a short run of RCA cables between the adapter and the monoblocks.  Success.  No hum, no feedback, just a silent connection.  Sounds petty good, too, when playing music.  
Thanks, all, for the help.  
 

The adapter that Emotiva sells does not do balanced to unbalanced conversion. It just dtops the negative phase signal, so you aren't getting any of the benefits of a balanced connection (significantly reduced common mode noise and elimination of ground loops). You need something like the Jensen adapter mentioned earlier in this thread to do a true conversion. 

But I'm glad to hear you aren't having hum problems. 

@holmz I was able to try your original suggestion. I was on Emotiva’s website to buy a 12V trigger and they had XLR to RCA adapters, so I bought 2 of them. I hooked up a pair of 20’ balanced XLR cables to my preamp, added the adapter just before my amps and connected a short run of RCA cables between the adapter and the monoblocks. Success. No hum, no feedback, just a silent connection. Sounds petty good, too, when playing music.
Thanks, all, for the help

Glad that worked out.
At least if it didn’t work out, then you would have had the cables needed for the Jensen isolators.

I have a bit of hum seen on a measurement spectrum from the TT, but when I play back file at +12dB I barely hear it with my head against the speaker.
So if it sounds good, then as they say say here, “You’re Larfin.”

Hopefully the next fellow or lady doing a search will find your thread helpful.
Thanks for putting a bow on it.

+1 for Kota1

I have a pair of 25' RCA interconnects with Mogami W2549 cable on Neutrik NF2CB RCA's (or a simpler less expensive execution would be to use Rean NYS352G RCA's).

Extremely pleased.

Good luck

Stay away from XLR/RCA adapters as they will diminish sound quality.

@ebm 

+1

Stay away from XLR/RCA adapters as they will diminish sound quality.

@ebm ​​​​@ghdprentice how do we explain this from 3 weeks ago:

… Success.  No hum, no feedback, just a silent connection.  Sounds petty good, too, when playing music.  
…

@holmz  I think we’re all right.  Let me explain.  I set up the balanced cables out of my preamp (Schiit Freya +) and ran them to the Emotiva XLR to RCA converters to another short RCA interconnect to Belles Aria Monoblocks and, eureka, no hum,no noise, just music.  Then, about a week ago, I swapped out the amps for my McCormack DNA-1 with same cable setup. Not good. Audible hum coming from the speakers as soon as I turned on the amp.  Tried the same test with a Schiit Vidar amp and same result — audible hum.  I then swapped out the balanced cable  with adapter connector for a long RCA with an RCA-RCA connector to the original short RCA cable and no hum.  Just silence and just music.  
I don’t know what the Belles does that made it work with the XLR-RCA setup but I’m convinced now that I need to go with just a longer quality unbalanced RCA between preamp and amp.  (Or get a fully balanced amp.). Going to hold off on that for a while to play with some new to me speakers — Vandersteen 3A Sigs.

@holmz  I think we’re all right.  Let me explain.  …

^exactly^

I believe that the 2 fellows that said that there is a degradation… also believe that they are correct.
And they are for their experience.

Hence they would have needed the Jensen transformer with the humming gear.

Where as with the Belles you did not.. sometimes one just needs to try it, but a spreadsheet of gear that the ordered from prone to less prone for humming would help.

Let me know what you think of the 3a sigs… They are generally able to consume a lot of one’s time in futzing with their placement, tilt, and toe-in… in order to make them sing in the space.
There is also a forum for that the brand.
And Belles is something that many seem to have used with success to drive them.