Has anyone experimented with switching the Havana

I did mine as well. It was a really solid improvement. Gives a better sense of resolution and just a better overall soundstage. For sure it would be one of those things that you don't notice until you do it, and then you can't go back after you do.

It was not hard to pull the old chips out and replace them with the new ones, either.

No - that's not what I'm asking! Which chips did you put in the unit??? :-)

Peter, excuse me I misunderstood. I'm prsently using the PCM56P-K chip with very good results. Having purchased four for $20, ( from outsource.net ) the results far out weigh the cost an time. But of coarse YMMV. Cheers.

Sorry - I must be confused. I thought the original DAC comes with PCM56P-K chips... When I have a chance, I'll have to open mine up to see what is in it.

I thought the same also, upon inspection my DAC had the PCM56P chips. So after a little research I discovered that the -K was a better sounding and more linear chip. Once in place though, there was an immediate difference in my system, difference being a more inviting soundscape and sound.