Requesting input from iMac users

I have been playing my iTunes library through (into) the main system via a Toslink coming from the headphone jack on the iMac to the input of the Krell HTS 7.1 processor. It sounds good to me, however, a friend is telling me that this is the lowest quality option for playing the music. According to him the headphone jack is putting the music out through a very inexpensive DAC in the iMac thus diminishing the quality out and causing the processor to accept the music via analog, converting to digital and then back out again in analog. A series of distortion causing steps.

I do have a Pop Pulse (never used) that would allow for coming out of the iMac via USB into the Pop Pulse and back out with digital cable (SPDIF) to the processor. Apparently this eliminates some extra DAC conversions. Would this be a better option? How do you do it?
I use the toslink out on my iMac to the DAC on a Music Hall Mambo integrated amp. It sounds just fine to me. I can't tell you if other options sound better because I haven't tried them, but if it sounds good to you, then why mess with it?

I believe that the Toslink plug and the headphone jacks share the same general area on the back of the iMac, but that they aren't the same. If you plug a 3.5mm headphone plug in, you will get analog output (through the iMac's DAC), whereas the toslink adapter should give digital output. I haven't tried plugging a regular headphone into my iMac. Can someone else verify this?

Your options include:

1) Sticking with the Toslink
2) Using a USB-based approach
3) Using an ethernet-based approach, such as a Squeezebox

I've used both the Squeezebox and Toslink in this particular system and they both sound the same to me.

Michael: I believe you are correct in saying that using headphone jacks give you analog output (into a headset) but when plugging a Toslink mini-jack into the same port you get digital output. That's how I had interpreted the iMac description of the headphone port in their manual but my friend had me wondering.

I'm glad to read that at least one other iMac user is happy with the Toslink connection. Thanks for the reply.

Your friend is sadly mistaken as your mac outputs digital. However, toslink is generally considered lower quality than coaxial digital. My understanding is that toslink cable quality matters a lot. I use (when I use toslink) a sysconcept cable. ( )

Some time back I had a pop pulse, it was relatively poor quality compared to my trends ud10.1. Its hard to say how the pop-pulse would compare to toslink, but I can tell you that toslink is a little bit more closed in sounding, with a somewhat more shallow soundstage compared to my toslink (set to 16bit output on the mac - it defaults to 24 bit, you need to open audio midi setup)
the sound you get from the mac is ok, nothing to write home about. when you attach a jitter device to the mac using the toslink to reduce or eliminate the jitter and at the same time converting to a coax cable, then attach an external dac to that, then you are getting there. forget about usb setups also. get an external dac that supports toslink and/or coax, those are still the best sounding.

I use Firewire out to an M-Audio Audiophile Firewire DAC. It sounds fantastic, and I have no issue giving up any of the traditional CD players I have used. I haven't tried the headphone jack, but there is no doubt that it will be inferior to the Firewire setup.

The M-Audio part isn't current, but it's worth seeking out used. Probably around $100 now. Try it, and I think you will be very surprised. A nice option is that you can record vinyl to digital if you are so inclined.

Good luck.
USB beats out the toslink on the IMac in my setup hands down. That was into a Bel Canto DAC3 at the time I tried the comparison. Using an Empirical Audio Turbo-3 converter now which is pricey but about as good as you can get for USB conversion.

At the end of the day, it depends on how much you want to spend and whether you're happy with the sound you have. USB should win out everytime compared to toslink, but the USB implementation of your DAC (or conversion device ahead of the DAC) is crucial and you generally get what you pay for.

IMacs are nice to in that they respond as well as any other source device to power cord changes and conditioners, but that's a whole other can of worms for people to debate.
Thank you for the responses I'll be checking out the advice!
@ Leahy

wow great tip! I just scored a m-audio audiophile firewire for $40 on ebay shipped. I cant wait to compare it to my trends. I figure even if its not as good (which I suspect it will actually be better) I can use it at the office for headphones.
Any reaction to I-mac -> Airport Express ->Toslink -> DA section on a CA840c?
This is where I'm heading but maybe I'm heading for trouble? I am in process of putting everything on my confuser in 'Apple Lossless'....
That setup will be prone to jitter unless your CA840 is able to reclock the signal.

Doubtful you'll be happy with the results, but if you already have all the equipment, might as well give it a shot.
magfan, get a jitter reduction device and place it between the airport express and the CA unit. you will hear a big difference.