Preamp has too much gain

I have a Consonance Reference 1.1 preamp that has too much gain.

I'm assuming by this you mean it is too loud with the volume barely turned up, but your assessment of the problem is not correct since you never use the gain that the preamp has. The stated gain of the pre is with the volume all the way up, but you don't have it all the way up (the preamp is attenuating the signal all the time instead of amplifying it) so the problem is it doesn't attenuate enough and/or the steps are too big (and here is the important part) for your combination of components.

It is normal to blame the pre because that is where the volume control is, but that isn't the correct analysis. You need a source that puts out less voltage, or a pre with more attenuation, or an amp that has less gain, or speakers that are less efficient, or some combination of these.

In line attenuators as suggested is one approach, or find components that go together better.

Very easy to fix, just need couple of high-quality resistor to construct a voltage divider.

Assuming your preamp has an input impedance of 100kOhm, then, to reduce the gain to 1/3, you can insert a 200kOhm resistor in series to the input RCA.

The gain will be reduced by 100k / (200k + 100k) = 0.33x, i.e. 1/3 in this example.

You can also use a high quality variable resistor, such as a Bournes pot then you can adjust the gain with a screw driver.

Wow, answers to a question I didn't even know I had. I have the same pre as Electra and always wondered why I could only turn it up to about the nine oclock position, (with zero being about 7 oclock), without it being too loud for your average listening session. My source is a Sim Audio Moon Eclipes, my amp is a Redgum, forget the model but it's about 150wps, speakers are Osborn Grand Monument Refs. Am I going to get a better/ different sound by doing some of the changes you have recomended, or does it really matter where the dial is set?