Hello all:
What am I missing here? How would I go about using my powered speakers, Kantos i pair 5's with my iMac? They have s video and rca jacks etc. but the iMac has only a headphone jack and usb ports. Is there a way to do this? I no longer need these speakers in a home office and would love to repurpose them in the computer room.
Thanks for any suggestions!
Get some conversion cables to go from 1/8" to RCA or USB to RCA. Look on
The simplest and cheapest way would be to run a 3.5mm stereo mini to RCA cable from the headphone jack to the powered speakers.

The jack is actually a dual output jack, headphone and digital optical, so for better quality you could get a digital to analog converter (DAC) with optical input and use a mini-Toslink to Toslink cable to the DAC, then use its RCA outputs with a standard RCA cable to the speakers.
thanks folks, I'll give this a try. Would anybody local like Best Buy sell this or do I need to order it?
I'm sure you could find one at Best Buy or Radio Shack but it will cost several dollars more and the quality won't be any better.
I got really great sound from my IMac by using the Audioquest DragonFly USB Dac and then I come out of the Dac with the 3.5mm (as Sfar mentioned).
I use high end cables that feed my Audio Engine 5+ speakers and Sub.
+1 Lak. The use of an outboard DAC would make for a significant sonic improvement over the headphone jack output. At $129 new the AQ is one of the least expensive.
Ok, so did this and it does work BUT I am hearing quite a lot of static from the speakers. I did not hear this in my office where the speakers used to be, and there was a laptop between them.
Any suggestions audio wizards?
Thanks in advance.
Do you have a source other than the iMac, an mp3 player or laptop, with a headphone jack you can plug the cable into? That would tell you whether the static is coming from the iMac or the cable/speakers.

If the static is still there with a different source you might move that setup to a different location to see if there's interference from something else in your computer room.

The object is to isolate the variables one at a time until you discover the problem.
Thanks Sfar: When used with my iPad mini, the static is pretty much gone. When I take the cable out of the iMac I can really hear the static. When I plug it back into the iMac, the static is back especially when scrolling through different internet sites. Always a low static but crackly sounding when moving anything with the wireless mouse.

Is this something that would be resolved by using something like a usb dac (Audioquest v.2 Dragonfly) as it would be plugged via usb port? I read where this device can really cut down on noise?
Thanks again for your help.
not sure if the outboard dac will fix your static issue but it might be worth a try and it will definitely improve the sound quality. if you have a high end dealer by you see if they'll let you try the dragonfly for a day or two, if not, see if they have a return policy, if not, buy one from audio advisor and return it if you don't like it :)

Im not savvy to computer audio... Is there a way to turn the volume up to the maximum level on the computer side and then use the speakers volume control to adjust the volume?
I did read on the Apple forum where making sure that the powered speakers are plugged into a different outlet than the iMac can be helpful. I tried this but it really didn't make any difference. I also read about using an RCA ground loop isolator, not sure exactly what that is. I do plan to try the audioquest dac as I would appreciate even better sound and hopefully that will take care of my static issues as well.
I did my homework before I purchased the original DragonFly. When the version 1.2 come out I picked that up also. I'm not saying that other Dac's aren't good, but I really enjoy the music from the DragonFly 1.2 (as small and puny as it is).

The DragonFly comes with directions that will walk you through how to custom set up your IMac for the best sound.

Music from my Audio Engine 5+ speakers and Sub literally sound as good and as dynamic as music comming from an expensive Audiophile system.

I spent a bit extra on interconnects and power cables also.
I'm stumped by the static issue. I've done setups like yours from several Mac laptops and an iMac and never had an issue with static.

When you say the static is "pretty much gone" when you're using the iPad mini it might indicate that the issue is with the headphone jack on your iMac. But if the static isn't completely gone I'm not sure if that's the problem.

You could try squirting some contact cleaner into the headphone jack on the iMac and plugging the mini-stereo cable into it several times to clean the contacts.

Or try switching from the wireless mouse to a wired mouse to see if interference from the wireless might be the problem. But if you still have some static using the iPad I'm not sure that would be a solution.
I tried it again and actually there is no static when I'm using the iPad. I'll try finding some contact solution and cleaning the headphone jack . I realize what I was hearing was the actual noise of the iMac itself as I was sitting in front of it when I had it plugged into my iPad. The noise really does seem centered around that headphone jack, and when I plug it back in there again I definitely get the static noise happening. Am I correct in thinking that if I use the dragonfly, this may beat as it will be plugged in via USB port?
The dragonfly most likely will provide better sound, but it also seems as though you have dirty or damaged headphone jack on the laptop. Cleaning could help, but it's also possible reasonably the noise you are hearing is from an intermittent connection at the headphone jack. Those little 1/8" jacks are easily damaged, especially if you've used the headphones much and stressed that connection by yanking, pulling, tripping over, whatever, the headphone cable.
Actually the headphone jack on the iMac has rarely if ever been used prior to this
try a pair of headphones connected in that jack. is there still static?

or, it may be a faulty headphone jack on the imac...
Well, just tried my Momentums in the headphone jack - clear as a bell. Put the RCA/3/5mm cable back in with the powered speakers and the static is back.....could it be that my lovely Radio Shack cable is faulty???
Yes, it could be. Sounds like you diagnosed the problem :) Still look into that dragonfly. For the $, it's a solid improvement
Good, yes, it does seem as if you've isolated the problem to the Radio Shack cable. If you want to be sure that's the issue it might be worth it try a different cable, such as this one. The Monoprice cables are of excellent quality at reasonable prices and they ship the same day you order.

An external DAC would be the next step up and while I don't have any experience with the Dragonfly since I've always used the optical output on Macs, it has a great reputation.
Well got the new cable from Monoprice - it looks and feels more substantial than the Radio Shack one - unfortunately, the static is still there! Very frustrating.
On a happier note, got the latest version of the Audioquest Dragonfly and am really liking this. When you play music, the static is not really noticeable which is nice. Once you start scrolling the internet, static is back...

By the way is there a way to use the Dragonfly with headphones and iPhone at all? Seems I read that the iPhone doesn't have enough power, but using a powered hub would do the trick - anyone do this?

Thanks for all your help on this folks.
I'm happy to hear you like the Audioquest Dragonfly.
Why don't you phone the place you purchased it from and let them advise you regarding your questions above? I'll bet they get those questions all the time.
I recommend you try Audirvana Plus playback software, made specifically for the Mac. You can try it for free for a couple of weeks. Learn how to use it to turn off other computer functions that compete with the music playback, and dedicate some RAM to buffer the music stream. This may reduce or eliminate the clicking and give you an overall better sound.

You will probably feed a cleaner data stream to your Dragonfly via USB with this, and even a Nirvana-decoded analog feed direct from the computer will sound better than iTunes on its own.
and .. and  ... the  2017 imac lost the digital out through the headphone jack.