Hi George,
I've been enjoying your Lightspeed Attenuator for three days now, and it prompts the following remarks.
As a lifetime analog fan, I only lately invested in a truly great CD player, an oppo 95 with Ric Schultz's all-out mods, only to discover that the digital volume control noticeably degrades information at lower -and what I would consider reasonable- levels. Additionally, the increments are less than subtle, and the lowest audible setting is still too loud for my taste. A friend told me that digital volume controls deserve to be banned. I concur.
In my experience a system's ability to resolve lower levels is essential. Not being the diy type, I started looking at stepped attenuators that plug directly into the amp output, and therefore would require one less interconnect. The only two I found, Ric Schultz and Scott Endler's, were unfortunately no longer made, and TVC's have their own issues. After discovering your LightsSpeed Attenuator on diyaudio.com, I ordered one a couple of weeks ago, which arrived safely ten days later.
I think the best way for me to describe the LightSpeed is that with the CD volume control set to maximum, I can now listen to my interconnects, not to the unit itself, because in every respect -style, size, sound, and setup- , it simply stands out of the way. I power it with an older car battery. It's always difficult to describe a product which has no characteristics of its own, whose presence is in its seeming absence, which adds or subtracts nothing, but the end result is that I now listen far more often to far more music which is far more enjoyable. For $450 I'm finally experiencing the full potential of what I consider to be an exceptional CD player, which now comes very, very close to my $15,000 analog source. I have yet to try the LightSpeed on the REC OUT of my phono preamp, probably because I am enjoying it so much on digital.
The only limitations I can think of, have nothing to do with the sound: leaving the volume control half-way to extend the life of the optoisolators took some getting used to, and indeed the lowest setting lets will let some minimal signal through, which compared to my previous setup, however, is well within my tolerance, and greatly superior to my earlier direct CD to amp connection. The overall experience is far beyond my expectation. This is a product that I will not be parting with, period.
You asked about the volume setting for normal loud listening with the Oppo at full. It's at ten of twelve maximum. If I want to increase that setting, I can then use the remote on the oppo while retaining excellent definition.