Unexpected preamp needed- return policy important


I need suggestions for a preamp. My amp is a Halcro MC20, powering Newform Research hybrids. I have a Cary 306 SACD coming next week.
Several months ago I bought an Atma Sphere preamp for the Halcro. While it sounded wonderful, there was a persistent buzz from both speakers. I tried everything to diagnose the problem, all without success. The kind Audiogoner I bought it from took it back. The pre worked perfectly in his system. So I hooked up an old Ah Tjoeb/Marantz player. No feedback. So I figured I would get a CD player with a volume control. My research was detailed but sloppy. I ended up buying a used Cary SACD 306 assuming it had a volume control. Just discovered that the Cary has no control. So I have to deal with the preamp issue again.
Out of concern that I will end up dealing with feedback issues again, I want to start the search with companies with a return policy. I know that buying new is not the best bang for the buck, but I would prefer not to face the same distortion issues without that safety net. So, suggestions? And thanks.
D1
deliberate1
If you are primarily concerned about a return policy, I think it would be easier to purchase from a store on the WWW rather thab trying to eliminate manufacturers. An example of an on-line store with a return policy is Audio Advisor (http://www.audioadvisor.com/). Quite a few other online stores have return policies.

You also might try to buy from a manufacturer who sells direct. An example is Decware (http://www.decware.com/newsite/homepage.html).

Whatever you do, speak to someone at the store/manufacturer about their return policy. Some have rather hefty restocking charges.

Of course, the disadvantage is you can't hear first unless you don't mind or car ride or you choose a seller close by.
I also had a slight hum when I got my Meridian G08. Lifting the ground from the power cord solved the problem. The other option was to get a power conditioner with a built in transformer to isolate the cd player. Lifting the ground was much less expensive and worked. So if you do get another device where you have a hum or buzz try a 'cheater' plug first (3 to 2 prong adapter) for the power cord.

I had the ground lifted in the power cord as not to add a dollar part to an expensive power cord and or change the sound.
If lifting the ground works,you can always remove the ground wire from the outlet.
Then you dont have to mess with altering the power cords. Just make sure that if you plug additional items into the same outlet they are only the 2 prong plugs.
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Ozzy
Where I live (a suburb of Chicago) all electrical has to be grounded via conduit and Romex is illegal here. BX is legal if and only if its added to and existing structure/electrical system. My outlets are self grounding. An ig (isolated ground outlet) would have to be added.

Just a side note depending where you live and what the electrical codes are. Violating a code and having a fire would negate any insurance policy. Something to also consider.