I don't own the LCD-4 but I do own the DAVE. Just jumping in here to share my opinion on the matter (flame suit on).....
First of all I'll just mention that the DAVE (like all Chord DACs) doesn't have an amp section, it drives headphones from the DAC's line-out, full time, whether from the headphone out or RCA/XLR outputs. The differences in the output is digitally controlled to either lock the volume to 3Vrms in 'DAC mode', or allow variable output digitally in 'pre-amp mode'. Nothing more than that. Rob Watts can do this because of the discrete Pulse Array DAC and the code he runs on the FPGA chip produce an exceedingly clean sound with enough current and voltage output to be able to bypass a need for a seperate amp section in the DAVE for the sake of transparency. So the comments of the DAVE's amp not being powerful enough are completely off the mark in the sense that the DAVE really doesn't have an internal amp like conventional DAC/amps.
Here's the thing that's always been bothering me as I feel it perpetuates myths and false perceptions of what's going on. If using a piece of gear at listening levels that are loud enough, with enough headroom for the more dynamic passages, why would an external amp be any different for drive ability? If the volume has enough headroom for peak dynamics then the unused portion of the available volume range and unused power is inconsequential from an external amp. The only real differences I find when attaching my Liquid Gold to the DAVE are simply the flavour the amp adds. I don't find that it 'controls the drivers better', whatever that means. Think about it,
if there is enough voltage and current for peak dynamics within the track for a given volume then the drivers don't care if there is more
unused power from the amp. Now none of this is meant to debate the legitimacy of using an external amp from the DAVE when the headphones do require it, or the synergy one finds from an amp to the LCD-4. I just feel that most of the time on Head-Fi when someone says an external amp is
required they aren't explaining the reasons why and just assume it's because an external amp has more power.
Again, I don't own the LCD-4 so I have no real say on the drive ability of the pairing.
I'm really only bringing this up because I know there are some seasoned Head-Fi'ers who find the DAVE drives the LCD-4 just fine and enjoy the DAVE/LCD-4 pairing very much without an external amp. If there was a serious power mismatch then you simply wouldn't see these comments. I believe we are really talking about synergy and preferences rather than drive ability here. It's not just the DAVE/LCD-4 pairing where this comment comes up either. I see it all the time with the multiple pairings of various hardware with mutiple differing opinions.
Personally, I find that adding my Liquid Gold to the DAVE makes
everything sound more similar. Sure, there's more bass impact and a wider soundstage but this is added to everything and with every track and with all my headphones (which are all well within the DAVE's drive ability). On the other hand, straight from the DAVE I find more variety in the recordings and more nuance within the music, there isn't the 'Liquid Gold filter' on everything. I like to use the Liquid Gold for the qualities it adds when I'm in the mood, but when I want to listen with the least colouration and transparency I hook up straight to the DAVE.
Let the comments fly!