Get an Audio Control C 101 Series III equalizer. They're no longer made but are very well made bone stock. They still sell for a couple of hundred dollars but are well worth it. I had one and could hear zero noise added from it. Build quality is excellent also, far better than what Audiosource makes. This will cost less than having the equalizer you have modded. Also it will retain it's value, the Audiosource you'd never get the money you sank into it back.
These are on Ebay and sometimes Audiogon will have one. My best recommendation however is the Behringer DEQ 2496 used in only the digital domain. Very versatile and totally transparent. Used ones can be had for 250 with the Behringer ECM 8000 microphone(a necessity). It even has an autoeq mode where you can set a curve and it will adjust it for you.
The Behringer has a very steep learning curve. If you go that route PM me and I'll be happy to help you.
