Gain setting for both pre-amp and Audio Research power amp w/ high output cart


Greetings.

I just put together an all-analog system consisting of a Rega RP40 TT with an Exact 2 cart, a Spectral DCM-10 pre-amp into an Audio Research Model-115MKII power amp. With a cart that is crazy high-output, my gain settings on the Spectral preamp are set to roughly 10 on dials that goes to 100, and an educated guess that the gain dials on the AR power amp are about 30% from zero.  So low gain.

LPs do sound amazing, really. Better than I ever thought possible in my room. There’s still a good amount of groove noise between tracks and in very quiet passages at hi volumes which is expected with that 6.2mv cart.

Question is, is there a relationship between gain on preamp to power amp in this situation that could alleviate some of the noise? Could I possibly go even lower on the preamp or maybe more preamp gain, even less power amp?

I expect simplest solution is to change to a .4mv MC cart but I’m not going to do that just yet. But is that the only solution?  It's hard to play with the preamp gain on the fly to experiment which is why I'm looking for direction.

 Any advice?

 Thanks much!


thxphotog
Have you tried adjusting the internal Left and Right gain trim pots on the main PC board?
Yes, as mentioned in my post they're at 10 on a 100 dial.  Last night I turned them even lower and turned up the gain on the power amp to compensate.  Keeping the 'reference level' on the preamp volume knob at about 11:00.  might be better but again, it's hard to adjust these gain ports on the fly and get immediate feedback which is why I posted here.  To see if anyone else has done this dance between amp & preamp gain w/ high output carts.
Post removed 
Sorry, I did not equate dials with trim pots in your post. 

Your MM cartridge has an output 6.8mv and your amp's input sensitivity is 0.6v.  The DMC-10 provides 30db MM gain and 10db line level gain, for a total of 40db. 

Gain required to drive you amp to full power can be defined as
20log(0.6 / 0.0068) = 39db

Based on the above calculations, the Rega MM cartridge is an ideal match for your system.  Are you sure you are not using the MC inputs?