Gain Question

Do you want it to be louder? If not you actually get the best sound with the volume control at or near maximum. If you don't want it to go louder you are in an ideal situation.

Your phono pre has quite a bit of gain so I suspect a step up will overload it. You need to fix it elsewhere.

I trust Almarg's math so if you do want it louder you need some more oomph from the amp. Since you are getting enough gain to get close to 2V into your amp if you want to go louder you have to get an amp that can get more power out with that input. Your low efficiency speakers simply need some more power.

Al, actually his Cary SLP-05 preamp has 10 db of gain single ended but only 8 db of gain balanced. I know, this seems odd.

So an amp with more power would solve the problem? My 40.1 Harbeths are at 86 db efficencey so I can see that as a problem but really love the sound of these Brits. Power on the top end seems to be the answer.

According to their website, the Harbeth 40.1 has a sensitivity of 84db/1W/1M.

You could use a SUT, but it would probably overload your MC input on your Herron. You could however run it into the MM input. If you got a SUT with 30 db of gain, and ran it into your MM stage with a gain of 43/48 db, you'd have a total of 73/78 db. This could give you as much as 12 db more gain before the preamp.

Cheers,
John

Your preamp is a low gain design. I find it interesting that the Cary website doesn't provide input sensitivity specs. It would help to determine where the gain mismatch is located. Either between the phono/preamp or the preamp/amp. Changing to a more sensitive speaker may correct the symptom(s), but won't cure the problem.