Tube Whine noise...Please Help


Hi everyone.

As a newbe to tubes I am having a problem that I need some help on. I just received my Musical Design SP-2 preamp and while it sounds wonderful, occationally there is a high frequency whine/whistling noise coming from one or both speakers. The SP-2 uses 2 6922 that the previous owners said were NOS RCA types. I want to know if the tubes went bad and needs replacing or if there is another problem that I need to look for. Thanks
speedracerucr
It seems to me that the surest thing I can do to eliminate the ringing/whining is to replace my tubes. Since this is the case, are there any low noise/low microphonic 6922/6DJ8 that you can recommend to me? As of now, I am probably not looking to tube roll with NOS. Thanks
Thanks everyone for your help. An update on my original problem: I replaced my tubes with 2 NOS JAN Phillips 6922s and the ringing is gone. Now that I know the problem was caused by bad tubes, I will start tube rolling with better NOS soon.
I would like to add to this forum by saying the SP-2B is a zero negative feedback design & as a result it will require specific tubes that are suitable for this design. Best to purchase a matched pair from Musical Design/ John Hillig who has done extensive research & testing on the right tubes for the SP-2B, that will work properly without exhibiting microphonics and the above mentioned problem. This is the best way to go.
I had the same issue (same tubes)-John suggested reseating the tubes--it worked.