Drop-in upgrade to CS3310 volume control
I'm surprised that searches here and audio asylum make no mention of the Burr Brown PGA2311 chip that's been available for as much as a year now. It's a drop-in replacement to the 10-year-old Crystal CS3310 volume controller chip used in many fine preamps of the past 8 years. Chip design moves forward so it's no surprise a better-sounding version would come from Burr Brown.
I just put a pair into my Sonic Frontiers Line 1 SE (it's fully balanced thus requiring two chips) and the results were a noticeable improvement, perhaps the best $11 (each) you could spend. At least Sonic Frontiers makes it easy as the chips are socketed and it took less than 5 minutes to swap them. So for all you Line 1/2/3 owners out there it's a no-brainer. I can't say if all the other preamps that use the 3310 have it socketed or soldered, or if you'll hear the same improvements from it that I did.
I heard a greater sense of presence and a bit more detail. And, notably, a wider deeper soundstage. Kinda like upgrading to a much better interconnect from the same mfg, but a whole lot cheaper! I ordered from Digi-Key, it's a normally stocked item.
Anybody know why this hasn't gotten any attention or reports until now? My thanks to Steve McCormack for bringing this to my attention during a discussion of my power amp upgrade. This new chip is the basis for his own RLD-1 preamp SMc Audio upgrades.