KOETSU VERMILION and audio research PH7

Check if there is any gain on your line pre-amp.  Most are flat but some have 10 or 12 dB of gain.

So I guess the output of your phono stage was just not sufficient to drive the Hera linestage for it in turn to produce enough signal voltage to drive your amplifier.  (The results are dependent upon the input sensitivities of each of the components in the chain, not merely their respective capacities to add gain, as I am sure you know but just for others to benefit.)  Clearthink, I beg to differ a little with what you say; most active linestages do add gain, typically 10db to 20db.  Unless one is using a passive attenuator, there will be some added gain from the linestage.  I'm not saying this is a good thing, necessarily; it's just most common in my experience of looking at specs.  A few phono stages that offer the option of being used as full function preamplifiers do use only a cathode follower in the linestage section, which adds no gain but permits the linestage functions, like introduction of a volume control and switching of CDPs, etc.  My Manley Steelhead is like that.

Is there any big diiference between the 0.2mv from VERMILION and the 0.24 from ZYX ? because as It seems, Koetsu do not mesure their voltage at 3.5cm/sec , and for my PH7 the voltage of ZYX 0.24 works very fine.

@andychris 
Even if it seems to work quite well now, I wonder would you say the same after hearing your low-output cartridges with a better matched higher-gain phono stage? They could sound good and still be held well back of their potential. Expensive cartridges are not cost effective unless configured to their full potential. 

If you're set on keeping the PH-7 for now, I'd strongly advise forgoing the 0.2mV Vermillion in favor of ANY of the other 0.4mV Urushi models (only the Vermillion is different). That will be a much better match for your phono stage. I'm not even saying the PH-7 is necessarily out of date or not great sounding, just that it seems optimized for a very specific output range of matching cartridges and the Vermillion isn't it. 

I've also had an Ortofon Jubilee (exact same specs as your Cadenza Black that replaced it in the Ortofon line) and it didn't sound as good as the higher output Cadenza Bronze (0.45 mV) on my Sonic Frontiers with similar config as your PH-7.

I had the sonic Frontier Phono 1 with the same tubes E188CC that my PH7, you can't compare those 2 phono stage, the sonic frontier doesn't make the music that the PH7 is able to do. I also had an audio research phono ref2 and I keep my PH7. Of course the 68db of the ref2 is fine on paper but there was less music out of the ref2,,, and I don't know why... but it's not a question of number on paper and kind of tubes.... the probleme is to get those components at home for a few days and make some A-B tests,,, and don't think about he price they cost, because more expensive doesn't mean better