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.
If only one source consider a high quality passive volume control with one in and one out.
Additional info - the Halcro and Cary are fully balanced, so looking for this in preamp.

Narrod, the cd is my only source. Can you suggest specific passive volume controls for me to research?
Tx D1.
The new mono design TVC is getting some very positive feedback from audiophiles who tried it. I am not sure about the return policy.
Another option would be Bent Audio passive - based on TVC (have not heard it. But if it is as good or better then original TVC, worthy contender).
Dodd and RWA both battery powered. Both great. Bought them for similar reason - zero noise or feedback. Ultra quiet, transparent with pitch black backgrounds.
I am sure others might have more interesting recommendations.
Good luck...Oh yea, if you have only one source: a better source with volume control could also make perfect sense....if you want to get the most from that approach, get yourself $50 Goldenjack attenuators.

Just my 2c.

Good luck
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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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.
Can you suggest specific passive volume controls for me to research?

The C-core ("Reference C-Core) and double C-core ("Signature") TVCs by Promitheus Audio are outstanding. Note that the Signature unit is not yet advertised on the web page, but it is available to order.

These Promitheus TVCs are very well implemented pure dual-mono (separate chassis for each channel) designs made with large transformers that are wound in house at the manufacturer's facility in Malaysia. The units are made to order and typically take about four to six weeks to be built after the order is placed. The TVCs are shipped by air into the U.S. with only two to three days in transit. I don't know whether there is any return policy, but you can write to the principal, Nicholas Chua, and ask.

When considering a TVC for your system, you will want to look at the input sensitivity of your amp to ensure that it is compatible with a TVC. Generally, you are looking for input sensitivity of 1.0V or less and input impedance of at least 50kOms.

Can you suggest specific passive volume controls for me to research?
I've had the Promitheus Audio Reference C-core for almost a year and I totally agree with Cincy_bob statements. Ever since the Reference C-core was broken in, I've been trying to hear any kind of sonic fault from its performance, but there is nothing but crystal clear sound.

There is lots of detail from top to bottom without the TVC sounding edgy at all. It's quite impressive to hear all this detail with the right instrument weight . I've heard many detailed systems before, but many systems sacrificed instrument weight and size. Also, it's soundstage definition and resolution is uncanny.

All this sounds good, but you first need to check if it can fit in your system. You'll need enough gain in order for the TVC to work properly. I checked with Nicholas to see if the Reference C-core would suit my system and he confirmed that all my sources have enough gain and the rest of the specs were within the parameters for a perfect match.

I first used it with one amp. I then I got a second amp and bridged them for mono-block use. With one amp, I needed to go up to 16-18 steps to play loud. With the mono-blocks, I only use about 50% (12 setps out of 24) of the volume control.

I got the Reference C-core TVC while at the same time searching for a top-notch tube preamp for my system. In the future, I may get an active tube preamp, but right now I'm not searching for one anymore. That's how much I like its sonic performance. I think that in the right system, the Reference C-core TVC is simply hard to beat.