I just installed a DIY power supply in my Bugle b/c I was getting tired of battery problems. Seems like the batteries would result in one or the other channel dropping out fairly regularly, and that was rather annoying. I could swap batteries and both would come back, as if it was some kind of imbalance in the voltage between the two sides that would cause one side to drop out.
So I built a PS based on the VSPS (Very Simple Phono Stage) over at DIY Audio and here:
http://phonoclone.com/diy-guide.html. I built it using an old 24.6v filament transformer into diode bridge, into 7812 and 7912 regulators. It's almost too simple and I thought it would be a bit noisy.
But...it is AWESOME! It has made a big difference in the sound quality, with stronger low end and more detailed presentation overall. High end is about the same as with the batteries (at least as far as my aural memory goes), and there's no noise to speak of (other than the expected hiss of the opa2137s in U1 and U2 positions). I intend to eventually build it into something more closely resembling the Bugle PS, with more filtering. I'd also like to somehow develop a split PS with more closely tied voltages, but right now they are both running pretty close to 12.1v, so no real problem with balance. I'll check it over time.
Best of all, I'm hoping I can go back to opa2134 for U1 and U2 positions b/c I don't have to worry about draining the batteries.
I'll report more later.
