I've done a fair amount of searching on the topic and have been unable to find anything that matches my situation exactly, and have managed to further confuse myself in the process, so a new thread it is. I am fearful that this is a dumb question, but want to make sure I'm fully understanding this and that there's nothing necessarily wrong with my unit other than it being mislabeled.
I recently acquired a used M-Stage (Class A OPA627AP). I had done some limited reading on the various gain settings and what is appropriate for usage for various headphones, etc., but it's all pretty new to me and I decided to just listen and see what sounded best, then compare that to the various recommendations I had come across. So in playing with it, I came to find that some of the things I was reading were directly contradictory to what I was experiencing. This is getting long-winded already, so let me just post the pictures:
This is the label on the bottom of the unit:
This is what's printed in the "instruction manual" that was in the box, which is entirely in Chinese other than this diagram:
And, for reference, these are the switches themselves: http://img59.imageshack.us/img59/8043/switches.jpg
Obviously, one of these is wrong, and I think it's the one on the label. I was initially operating under the assumption that the listed dB levels were actually negative, whatever the opposite of gain is I suppose, but after reading others' statements and recommendations and digging the "instructions" out of the box, I think the label on the unit is just plain wrong. 0dB gain is described here as allowing more fine adjustment of volume, as the travel within the comfortable range is greater, and more gain is said to be suitable for higher impedance cans, both of which are exactly opposite of my findings if I were to trust the label on the back of the unit. So, my questions...
* Both switches down (away from ON, 0dB in instructions, 20dB on label) is relatively the quietest, I can turn the volume knob to one or two o'clock comfortably, whereas I can only go to nine or ten o'clock with the same headphones with the switches in the opposite position. This means that the both switches down position is is actually 0dB gain, correct?
* Is there a situation (different configuration/different product/etc.) in which the label on the back of the unit would be correct? It seems not to me...
* Is this indicative of anything faulty other than a backwards and incorrect label?
* Is this an isolated occurrence? As I mentioned, I couldn't find this issue either here or on Google, did I miss something somewhere?
Thanks for any assistance. Typing this out has actually made me more confident that I am correct, but I'd like to make sure as I was thoroughly confused there for awhile... Thanks!