low pass filtering the feedback of a comb filter??

I am attempting to build a reverb and have just come across Moorer's article which explains a method for building a reverb simulation of Boston Symphony Hall. The method is a tapin~ with 19 tapout~ at specific times. This is patched to 6 parallel comb filters with low pass filters in the feedback chain, then into an allpass. I first built the comb filters from 6 individual tapin~/out~ with a onepole~ in the feedback chain and controllable feedback. This method works alright but its a little grainy and it rings a little. I then tried it with the comb~ object and got a much better result with longer decay time. The only problem is that as comb~'s working are all done inside the object I can't place the low pass into the feedback chain. Has anyone any suggestions about how to either make the tapin~/out~ method sound a little nicer or how to get a low pass into the feedback chain of the comb~ object?

Cheers,
John