cartridge output level

As an aside from the current discussion:
The Thor Cantantus has a fixed resistor that you can specify, is best for cartridges at .65mVolts but my Sumiko Celebration at .5mVolts works fine. My preamp lacks a phono preamp so it was necessary to get a separte piece.
Check and see if the SUT is in, a voltage reading should tell Hovland that info, let them instruct you just in case, working with live units is for people trained to do so.
As a former electronic tech, better safe than sorry

Rlawry, according to Marco's reports, he's getting ~0,9v at the output with the SUT in the circuit (63dB) -- before even hitting the active pre... and that's the reported overload ceiling of the phono.
Strange, as you & Marty note.

Rlawry, that formula made me think a lot, for example, based on that, if the SUTs were out of the circuit the total gain would be 60 dB (77-17), and the max preamp output 0.45 volts, so am I correct in ruling out this option?
I don't know the gain of my power amps, but I know that, in my room with my system, when I use the CD I'm happy with the volume at 12 o'clock. Now, this CD has an output of 2 volts, the line stage has 14 dB gain, that means according to the formula a max output from preamp of about 10 volts. Let's assume that, to make me happy, I need 3 volts out of the preamp, and that happens when the volume knob hits 12 o'clock in CD replay, it would make sense that, to get the same 3 volts in LP replay, I need to hit 3 o'clock, in the noisy area, being the max output from phono 3.2 volts as per your calculation.
Bottom line, to bring the voume back to 12 o'clock with LPs, I think I need to increase the voltage gain of the phono stage, just as you said, and to do so I only see 2 options:
1-Outboard phono stage with higher gain as you suggested, is your Rhea noisy @ 75 dB?
2-Cart with higher output level, a 0.6 mv one would give a max output of about 4.3 volts, would those be enough to bring the volume back a few clicks down?
Hmmm, decisions, decisions, life is hard...

I agree with your statement that your CD output of 2 volts will lead to about 10 volts output from your preamp using the linestage. But 3 volts output from your preamp should still be enough. The only thing I can think of is that the taper on your volume control is such that the gain is low until 12:00 or so and increases rapidly after that, but still, it should not be encountering much noise in your preamp unless the tubes themselves are noisy. I have never tried the 75 dB gain position in my Aesthetix Rhea, but even with 62 dB I had to buy some low-noise tubes from Upscale Audio to minimize tube rush because the phono stage uses tubes for all of the gain. One time a tube was going bad and causing big thumps through my speakers and subwoofer. Going to 0.65 mV will help, so that is a solution, but there are a lot of solid-state phono preamps that go above 60 dB. Again, I think Hovland should be able to help you.

What I'm getting from all the above is that you SHOULD have plenty of gain/volume at 12 o'clock. There's an error somewhere. Call Hovland and make sure your Colibri is actually not a VERY low output version.