Ideas for reducing gain on a Belles 21A pre-amp?

Using a Belles 21A pre-amp with a Belles Reference 150A amp,
Silverline Audio Prelude speakers Sensitivity: 91 dB, (but actually measured lower by Stereophile at 87.7).

Getting too much gain. It's usually loud enough at 9:00 on the volume knob.

I'll be doing surgery to it shortly to install the Auricap upgrade. While I got it apart I'm wondering if anyone here is familiar enough with the circuit to suggest a mod to lower the gain a bit?

I know people are going to suggest contacting Belles, but I couldn't get much help last time I called them, so I'm not going to bother.
I wanted to bump this thread as I am having the same problem using my Ray Samuels B52 (as a preamp) feeding my Edge NL12.1 power amp.

The 23-step Dact attenuator is usually at 4(too low) or 5(too high). I am going to try a pair of Rothwells (cheap!) but I saw comments that they blunt the sound.

I noticed other ideas here in the forums but I just wanted to ask for up-to-date suggestions (aside from trading for a new tubed preamp, which I will consider later on).

I love the tonality and richness of the B52, so I am trying to make it work if I can.
Harrison Labs 12b attenuators cheaper than Rothwells and do not blunt the sound.
Hi there and thanks for the comments.
The B52 does not have gain switches (I wish it did.)
It's surprising how common this problem is. I have to wonder why manufacturers design preamps with so much gain. Five or 10db should be adequate for most systems. The 21a is rated at 17db.

I used 10db Rothwell attenuators to tame my preamp and it worked to some extent, but I never had the kind of control for low level listening that I wanted. Maybe 15 db attenuators would have helped. I don't know.

For what it's worth, I had a similar experience when I contacted Belles about a problem with a 150A. No response. Fortunately, my problem went away without needing any work, but it bugged me that David didn't seem willing to help. Yes, he's in business to sell gear, and he probably doesn't have a lot of time for non-revenue generating questions, but companies that stand by their gear get rave reviews from customers and those raves usually lead to sales.