[senns&nonsense]

Will a USB DAC (Headphonia?) be an improvement over running straight through from my iMac? I know that many people with ordinary sound cards have enjoyed a SQ boost, but I haven't heard anyone compare using a DAC as opposed to a Mac's sound card.

Also, if I run the same lossless files from a 4th Gen iPod connected to the mac through a dock, how would that compare?

Either way I am getting an inexpensive amp. Just wondering whether it would be better to get one with a DAC. I am usin Senn HD595.

Thanks for the advice.

 

[mriguy2]

Some thoughts and clarifications for your consideration...

The sound output of Macs is no competition for an external A/D converter/headphone amlifier. I use an Appogee Mini-Dac from iTunes via USB. The difference between the headphone output of the computer and the Mini-Dac is enormous, if not laughable.

With regard to the iPods dock connector... remember that the audio signal available at this port is a line-level signal that has been taken from the iPod's D/A converter, before it was given to the internal headphone amplifier. Use of the bottom port requires a special cable (like an Audio Line Out cable) and an external amplifier. The signal on this port is analog, but is not capabile of driving headphones directly. Nor is the output at this port digital... it cannot be given to an external D/A converter of any kind.

In conclusion, so yes, get an external USB D/A converter for you main computer. Get an ALO dock connector and an external amplifier for you iPod. My favorite amplifier is a Tomahawk... do it once, get it right and be done with it once and for all, if you can at all afford it.

 

[senns&nonsense]

Thank you - good advice and helpful!

One question.... the "line out" on the back of the dock does actually play when I attach my headphones using the regular 1/8 jack. There is no volume control, but it plays. Hypothetically, if I just got an amp (no DAC), wouldn't I run the 1/8 jack from there into the amp? I will probably take your advice and get a usb miniDAC, but I want to understand the options and how this could actually work.

Appreciate the help,
Joey

 

[senns&nonsense]

Just took a look at the Apogee miniDAC. Unfortunately that is beyond my budget. Is the choice to go to a usb DAC as obvious if my budget will allow, for example, the Headphonia in the low $200s?

Hearing from any others with similar Mac experience would be really helpul.

 

[iPodschun]

Intel iMac user here. I don't know the quality differences, but if your iMac has optical out, remember you have that option as well. It will free up the USB slot and also allow you to get a full size DAC instead of a miniDAC.

Also, you are correct about the iPod line-out. The iPod uses its internal DAC so you just need an amp.

 

[redrich2000]

I just got a Fubar II USB DAC and it sounds great. They sell for $120 plus shipping from Firestone Audio (linked head-fi sponsor). There are cheaper USB DACs than this. Like this one on eBay. I haven't heard it, but it comes from the same people that sell the Zhaolu DAC which is very highly regarded.

 

[Calroth]

You connect the iPod line out to a headphone amplifier - that's why they included a line out!

You could also connect the headphone jack to a headphone amplifier. Some people claim that there's no difference in sound quality between that and the line out. This is something that you can decide for yourself.

 

[melomaniac]

Quote:

Originally Posted by senns&nonsense /img/forum/go_quote.gif Will a USB DAC (Headphonia?) be an improvement over running straight through from my iMac?

absolutely - it is a big difference: 1) it bypasses a lot of cheap parts for the headphone out, 2) it has lower jitter than most other ways of getting good sound out of your iMac, 3) a decent USB DAC can be inexpensive.

depending on the age of your iMac, you can (utilities->audio midi setup) enable 24/96 output, which might give you even better sound from the optical out of your iMac into a really good DAC with optical in. USB right now (AFAIK) is limited to redbook CD quality 16/44.1, but it certainly can match most mid-fi to moderate hi-fi sources to hook up a quiet computer to a decent USB DAC.

 

[senns&nonsense]

Thanks very much! One new piece of information...

I talked to an engineer at TXN today who spoke at length about the 3052 chip in my iMac and the pcm 2704 chip in the Headphonia, the Corda Aria, and others. He said the chip in the mac is better in both DAC processing and clarity of output. Both chips are made by TXN so he was just very responsive and carefully went over the specs while we talked.

He did not have an opinion on the subsequent degradation of the signal working its way through the computer which obviously alters the calculation from my perspective. It does make the decision to spend a bit harder however, given that at least in some ways the usbDAC would be a step backward.

Also, Melo, I have set the audio out to 24/96. My optical out is the same 1/8 jack. Would the proper connection be mini-jack to toslink? Thanks for the advice.

 

[senns&nonsense]

Sorry about replying to myself here, and I obviously know very little relative to many on these boards, but maybe someone will find this useful.......

Spent a good deal of time today reading about sound out of a Mac and different ipods and docks. Also spent some time listening critically to the current meager set-up - the last pre-intel iMac, a 4th gen. ipod w/ universal dock, HD595s, and all Apple lossless files.

The most intreresting thing is the quality of the sound out of the dock even though it is a line out and there is no volume control. Even unamped (and I know it needs one) it has a great presence along with a bit more detail than the regular hp jack on the ipod. With equal volume it was also higher quality than the iMac's hp jack.

Right now I will continue to use the computer so i can adjust volume and I like a bit of tweaking with the eq now and then. But I am thinking that a amp w/out DAC attched to the line out might be the right call for me. And if that sounds as good amped up as I am now hoping, perhaps a red wine mod of my ipod might be the best place to burn through the next $200.

Any thoughts appreciated.....

 

[melomaniac]

Quote:

Originally Posted by senns&nonsense /img/forum/go_quote.gif the 3052 chip in my iMac and the pcm 2704 chip in the Headphonia, the Corda Aria, and others. [...] the chip in the mac is better in both DAC processing and clarity of output.

interesting - maybe the difference really manifests itself only with a significantly more, erm, expensive DAC (not to put too fine a point on it), and if so this would be an argument against using one in your situation: but I'm not sure that the chip is the whole story, lots of gear uses the same parts and does not sound the same. also, I feel that with the laptops I used over the past few years, even a relatively inexpensive DAC/amp like the total bithead makes a significant difference (i.e. the use of USB instead of the headphone out). keep in mind, some of it is in lo-tek factors of convenience: no cable noise, no questions about the lock of the cable.

Quote:

I have set the audio out to 24/96. My optical out is the same 1/8 jack. Would the proper connection be mini-jack to toslink? Thanks for the advice.

well, yes - although both are in the same jack, different cable is needed. but I've even seen people claim (not just about computers but about different options on DACs) that the optical is not always better than the USB, even though it can carry your higher-resolution signal. in my experiments with SACD and DVD-A versus standard 16/44.1 the difference was small enough to be overshadowed, if not obliterated, by hardware factors.

ultimately, I think your posts here continue to look at two different scenarios: computer and iPod. as for the iPod, I agree with you on the dock out (obviously since I have an ALO dock and love it). in fact right now I am listening to giant steps (coltrane) from the iPod, hooked up to my big amp via ALO dock and total bithead, and it's quite acceptable. I tried the Apogee miniDac you mention, and was not convinced that it was worth buying for the computer, so I got some amps that have built-in USB.