MAJOR ROADBLOCK
I had mentioned in my short first impression of the TT setup that it is good but I am not satisfied with the PRAT. I did not elaborate it more because I myself did not know exactly what is missing. Just that the sense of immediacy and drive that makes one tap his foot was not coming through satisfactorily. I thought I will allow the cartridge to break in and try with some isolation platforms etc etc.
Cartridge has actually reached about 30 hours of play time and has improved from day zero to now. However the "full of life" sound of LP which in the first place got me hooked to analog was not coming through.
I have a simple headphone setup which comprises of a AKG Q701 and a little tube headphone amp. This combination somehow has a very gripping presentation. Very honest, musical and great timing. I used to take it to all the serious TT evaluation process and after listening to the TT in the main rig I used this little setup to cross check my evaluation and it always gave me a very accurate insight of the TT setup.
Yesterday, as usual I was listening to my TT on my main rig and suddenly it struck me that I havent used my little headphone rig on my own TT setup. So, for sake fun I dug out my headphone and the little amp, connected them to the TT setup. So my headphone amp was connected directly to the Leben phonostage. Guess what....MIRACLE !!! Glorious music with amazing dynamics, great timing, "full of life"! I was astounded. This is what I expect from a TT setup of this level and it is all there. To double check I played quite a few known LPs. The result was loud and clear, the sound was superb.
why didnt it sound the same with my main rig ? Suddenly something flashed to me like a lightning. My Leben phonostage is an all tube equipment and obviously has a tube output stage. My Naim integrated is a SS design and that too its preamp stage is passive. Generally a tube output stage has a very high output impedance and an SS amp WITHOUT an active preamp means relatively low input impedance. Bad match !! Off I went to my laptop to google out the specs of these two gears. Here is what I get:
Naim Nait 5i:
Input Impedance - 20 kohms
Leben RS-30EQ phonostage:
Output Impedance - >10
kohms 
:sad:
This is unbelievable. The general theory is this ratio should be at least 10, more the better. In my case it is less than 2
. No wonder that the sound did not have enough life and drive. I am sad:sad:. I did not expect to meet a serious road block so early in the journey. Moreover the leben phonostage is soooo musical, it was the first thing I bought while shopping for TT setup. Now it doesnt work in my setup. Either I have to buy a tube amp like a Leben CS300 which has high input impedance or change the phonostage to something else which has low output impedance. Either case I lose my preferred combination. The Leben CS300 is very nice but for my Tannoys I need at least 30 watts (CS600 is out of my budget). Moreover the Naim combo really rocks and has settled in very well with the speakers. My idea was to go higher in the Naim ladder slowly. It cannot happen if I retain the Leben phonostage.
This is a silly mistake, how could I miss the specs so badly. Anyway, I am at least relaxed that I found this issue early otherwise I would gone for upgrading other areas of my system just to fix this issue but I could have never got it right because of this serious mismatch. I saved myself from that frustration and of course blowing money on unnecessary upgrades.
I will be putting the Leben phonostage for sale. I dont know what I can replace it with, I will have to research.
. Just like the best tubes and SS gears try to converge their best qualities and sound alike, similarly the best DD, ID and BD turntables converge. PRAT is not a function of speed and torque alone, if that was the case isolation of TT should not affect PRAT, but it does. PRAT is a very complex subject and almost everything in a TT can be tweaked to get better PRAT but I will be touching some fundamental areas (as suggested by some Verdier guys) when I get down to it and post the results here.
