Needing service for Acoustic Research solid state preamplifier

AR only made 2 preamps: C-06 // from 1986-1989 and Limited Model 2 - 1993.

My point of mentioning, the only 2 models, is they where not made in  great quantities, especially the model 2. I thought it was odd that someone might want to sink money into these preamps. 

I also think the OP might mean Audio Research which would make more sense to service & upgrade. Maybe by my mentioning this the OP would chime in here and clear things up.