Parasound A-23 or Parasound HCA 2200

I bought an HCA 2200 on ebay for $377.  The right channel sounds great.  The left channel, not so much.  That is when the left channel outputs anything at all, which is not the norm.  Removing the cover I see that the small capicators to the sides have leaked.  Both sides.  If I could get the thing up to spec for a couple hundred, I would still feel like I got a pretty good deal.  I don't have a clue as to what that would cost.   The folks in my area that do stereo repair are TV repair places.  I worry about the cost of sending it out as this beast weighs 65 pounds.

Although I like the way right channel sounds, I don't get much volume, which is unexpected with an amp that delivers 385wpc into 4 ohms.  But it could be because I am running my portable DAC (ifi nano with burr/brown - 32/384 async and 256 DSD)  directly to it without a preamp.

So my next question is:  Assuming I can get this thing repaired at a reasonable price, what is a good budget preamp to go with it.  By budget I mean around $300.

One more thing:  I love this site.  Everyone is so knowledgeable and helpful.  Thank you everyone for your comments so far.

In case anyone is still following this thread:  I swapped out the interconnects and ran it some more and it seems to be OK now.  I don't know if the issue was actually the interconnects or if the unit just needed more warm up, but it has been working and sounding nice (even with no preamp) for about a week now.  

Wifey wants to go on vacation, so the preamp purchase is on hold for a month or two. 

I probably will have the unit looked at, and I bought some better interconnects.  (Oxygen Free Copper with crimped connections and specific resistance -- not real esoteric  but at $50 for .5 meter used, they are at a good price point for me)