Ok, if you remember this thread of mine:
I probably made one of the dumbest statements I've ever posted online in the title of that thread - "I'm done!" HAH! Yeah right....
Since I wrote that thread, I've gotten new speakers (2B's became 1C's), all new cables (Signal all the way), a PS Audio UPC-200, and a room full of acoustic treatments. And now.... I'm about to change a whole lot more.
The only thing that's bothered me about this system is that I get a buzzing that's noticeable in between songs. The tube pre-amp has adjustable gain - at a gain of 3 the buzz is tolerable. At a gain of 10 (where the amp needs to be set for my 300ohm Senn headphones), I need to leave the room it's so loud. I returned the preamp and they sent me a new one, same problem.
So Little Tube is being extremely cool and letting me return the MKIVSE preamp for full price towards their new flagship model, which is balanced:
Now that's a beauty! So now I need a balanced source. Easy enough. Squeezebox digital out into the new Little Tube balanced DAC does the trick:
Of course, I can't skimp on the digital out of the Squeezebox, so sent the Squeezebox back to Wayne at Bolder Cable to have him finish off the Enthusiast mod package with the digital mods. Previously I had only done the Analog mods.
Why am I so excited about balanced? Mainly for headphones, to be honest. It is simply breathtaking what a balanced headphone amp and cable can do for my Senn 650's. I demo'd a balanced amp with my cans at a head-fi meet a few years ago, and just couldn't believe what I was hearing.
Problem is, Little Tube suspects that the cause of the buzzing might actually be an impedance mismatch between the amp and the pre-amp. If that's the case, it may be time to look for a different amp. The mod's I did to the NAD 2200 sound just awesome, but if a mismatch is causing a buzz, then it will have to be replaced.
I'm not an engineer, so I'm not overly technical, but my basic understanding of balanced is that the left and right have completely isolated power supplies, and then use the 3-pole XLR connectors. Now I would think that having completely separate power supplies would mean that it is not common ground thus making it a no-no for SDA's. I could be completely wrong there, but then that's why I'm asking!
If I do need to replace my amp, then given I'm running a balanced source and pre-amp, it would of course be tempting to use a balanced amp and see what it can do for the loudspeaker side of my system. But it would need to be compatible with SDA's.
I suppose I could always build an AI-1, but that's added work...
Any thoughts? Thanks in advance.