Where to start :-). 1st, relax about what jafox said - he was addressing the comment to someone with very high level expectations in an advanced system/setup. That SP10 is a far better pre-amp than many new ones sold today and the phono stage is still world class.
You have good ears...if you can tell the difference between the high and low gain stages. My compliments. The low gain stage should be slighly (!) less transparent, you are putting an attenuator in the signal path of the source (Shanling in this case). ARS is the name of the tube retailer, it is not the name of the manufacturer. You will have to gently pull one of the tubes from its socket - you will then find on the tube the manufacturer's name.
Before you start doing a micro exam of tubes etc, I would suggest that you make sure that your speakers are set up to their best advantage - to do that you must have an understanding of their radiation pattern - some speakers are meant to be pointed straight ahead - to listen to them pointed at your listening position will make them sound very aggressive and bright. Such speakers have a wide radiation pattern and will bounce sound off the wall (ceiling & floors) which you refer to as the 1st reflection points - these points must be deadened or the reflected sound will hit your ears mili seconds after the direct sound from the speaker - this will increase the apparent amplitude of the highs and muddy up the direct signal. Since you are dealing with high frequency signals you can usually deaden this area by using heavy wall hangings, book cases, etc - most anything that absorbs sound. As a temporary test, just hang some heavy wool blankets on the walls adjacent to and slightly ahead of your speakers. Also make sure that you have some type of deadening materiel on the floor (carpet/rugs). I have also had a lot of success in small rooms crossing these types of speakers so that the axis' cross well in front of you, at about the same relative angle to your listening position as they are when pointed straight ahead.
Once you have done that, then I would suggest that you become very logical in your approach to solving your problem. I would start with the CDP (which I suspect may really be the problem). Listen to other sources, the better the quality, the better the test. Listen to the Shanling in some ones else system if your can and see how it compares. If you rule out the Shanling as being a problem then you can go to the next step - FWIW, this pre-amp is not euphonic but it is not(!) inherrently bright. Its like an old Ferrari - its still very capable of very high performance if set up and maintained properly but its not one that you would want to just drive about town and to the grocery store.......Hope this helps and feel free to ask more questions, we all want to help.
