Can a preamp's gain be lowered?

My DAC seems to have too high an output - I've had preamp manufacturers lower the gain of an input for me. They were able to to -6db.

I built my own balanced attenuators for the input side of a tube preamp using Vishay resistors from Partsconnexion. I was able to try a few combinations first then zero in on the level of reduction that worked best. I also tried the Endlers, which were ok, but not as good as the ones I made. You could easily build them inside the preamp, and that way you would only have to reduce gain at one of the inputs. I would stick with the least amount of attenuation that works for you, since I believe that attenuation reduces dynamics.

I would second Mitch2 both on building own with the least attenuation that works and on reducing gain at individual inputs. The second point may be more important on older equipment where phono/tuner outputs are lower than on the digital source. Can make a big difference in "listenability".
If not here someone at the diyaudio.com will tell what value to use. It's pretty easy to diy and you can pick the parts. Good luck.

Thanks for your suggestions.

07-26-08: Mitch2
I built my own balanced attenuators for the input side of a tube preamp using Vishay resistors

Is it better to put the attenuators on the input rather than the output to the amp? I'd really like to see your circuit and the values you used. I'm comfortable with diy.

Since your preamp uses 6SN7s and you say you are comfortable with DIY, you might want to try something similar to the modification I made to my Supratek Chenin preamp. I built two adapters that let me use 7193 (aka 2C22) single triodes instead of 6SN7s. They are half the gain of a 6SN7, cost $5-10 each, look pretty cool with their dual top caps, and IMHO sound much better. I have detailed the modification on the last page of the "Preamp Deal of the Century" thread if you are interested.