Here's a really ugly thread, but Dale sheds some very helpful light on the matter:
Originally Posted by KarlHouseknecht
I think "flaw" is a strong word. Perhaps we could say that there are some design decisions made in the first gen unit that may not have been optimal?
1. No power switch.
2. Power plug outer shield is exposed and subject to shorting.
3. USB too close to power input...easy to fry the unit. Has been done.
4. Input configuration makes it near impossible to achieve unity gain.
5. Effects loop difficult to achieve unit gain.
6. First gen unit is arguably underpowered in the DSP section.
7. Switches are of suspect quality. (yes, lower failure rate than X3, but still...the sight of them...
Line6 appears to have addressed at least two of these "flaws" in the new unit. That's commendable. Would be great if some of the other ones had been too.
1. As you point out, they are design decisions, not necessarily flaws. ...bend over to switch it off / bend over to unplug it ...meh! (for the record, I'd also prefer a switch, but I was out voted by the product manager who felt it wasn't needed).
2. The DC power connector and power supply are both off the shelf parts used on, literally, millions of products world wide.
3. USB is present on millions of products as well. It is important to keep the digital & power circuits as far from the analog circuits as possible to minimize noise in the unit (hence putting power in and USB far to one side with the MIDI jacks between them and anything analog). I've honestly never heard of someone plugging a DC jack into the USB port. Furthermore, the barrel of the DC jack is (neg), and the case on the USB is ground ...as far as I can tell, it is impossible to "fry a unit" by touching the two together!
4 & 5 ...I've got nothing. This may be a legitimate concern (it probably is, in fact) it's just something that I've never had an issue with using my guitars / amps.
6. The HD500 had as much DSP power as could be had at the $500 price point at the time. Even now, a couple years later, you can't get a huge increase in DSP for the same money. ...what can be had (that would work with our existing architecture), we put in the 500X to help alleviate the "DSP wall" for people who use DSP heavy dual signal paths.
7. I don't know that I'd call the old switches of "suspect quality" but anytime you have failures in the field, even when they are statistically a very small number, that perception is hard to combat. ...the new switches should prove to be an improvement in both durability and feel (as well as LED visibility). The switches also have a slightly longer throw to accommodate user feedback.
Karl, I'm just quoting your post to address comments some others have made, not taking argument with your comments / complaints.
I want to note that Dale's post was 1. informative, 2. addressed the presented issues, 3. exhibited patience, and 4. didn't resort to any insults, attacks, or attempts at misdirection. In reading that thread, I noticed a few usernames from here copy-pasting the same irrelevant character-attacks and other damage-control strategies that were posted on this board during "DSP-gate." Google brought up the same posts on Harmony Central and other sites hosting threads dealing with word-of-mouth misrepresentation of the unit's DSP. User profiles on thegearpage.net have accordingly been annotated with their Line 6 affiliation.