What is the latest thinking on whether it is worthwhile to have a DAC in a portable amp? If iPod/iPhone output is analog is it worth bothering?
I think it has value, especially if it's a USB DAC.
And what is your definition of portable? Battery powered? Or merely less than 50 lbs?
Contributor to The Absolute Sound, EnjoytheMusic.com, Vintage Guitar Magazine, and other fine publications
I also think so.
Definitely battery-powered. Also small (roughly the size of an iPod). I just don't see what another DAC does for me (I do see that if I wanted an amp for my PC that would be different). And maybe that's the source I should use?
Several thoughts to consider:
1) A DAC is certainly worthwhile if you'll be doing some of your listening directly from a PC or MAC laptop. Today's best portable models have very high-quality 24/96 DACs.
2) iPod/iPhone analog outs: Be aware that there are two fundamental approaches on this. You can take the analog output from the iPod/iPhone's headphone amp, which is what most people have done in the past. Alternatively, you could acquire a cable such as one of Moon Audio's LOD (Line Out Dock) cables that will take a line-level signal from the iPod bypassing its headphone amplifier altogether (the sonic improvement is really striking, IMHOP). See Tom Martin's recent blog on the LOD cables: http://www.avguide.com/blog/first-listen-moon-audio-silver-dragon-ipod-lod-line-out-dock-cables
3) Battery power is, or can be, a good thing, though it typically entails carting around wall-chargers (which can be a pain). In the case of some Amp/DACs I've encountered, though, there is the option of having USB power (where the USB cable acts as both a data cable and as a "power cable"). One interesting design that sort of "splits the difference" is the iQube V2 amp/USB DAC, which is battery powered but designed to be charged via a USB cable, again going with the them of USB as both data cable and power cable. The cool part about the iQube V2 is that it also has conventional analog inputs, so that it's iPod/iPhone friendly.
Best, Chris Martens
Editor, Avguide.com/Playback/The Perfect Vision
When are we going to get a portable solution like the excellent Wadia iTransport? Your point (2) above is well-taken and I have been using an ALO cable in that config with my RSA Hornet amp for several years now with good results, but I found the improvements in a home setup being able to get a digital out an even greater order of magnitude improvement. Does not seem like that big of an engineering challenge to integrate this feature in to a product like the iQube and then you would truly have a portable audiophile setup.