Help Loud pop when muting BAT VK-3i preamp


Hey guys! I just got a BAT VK-3i installed in my work-in-progress listening room. I had the guy still in the box for a few days, but wanted to wait until I got my dedicated lines installed to fire her up.

NOW...

There seems to be one small problem with the mute function. Whenever I press mute on either the remote or the front panel of the unit, I hear a very loud "pop!" from the left speaker (Magnepan MMG), primarily (maybe there is something in the right speaker, but I cannot hear it over the very loud pop in the right speaker). Also, when I turn the volume down to "00" I get the pop (because the muting is engaged) and when I power the unit on, after the tube heath 60sec check-up/delay I get the pop again. Now, I've rotated out my amplifier, my speakers, the interconnect between the amp and preamp and I had the "pop!" with every iteration. Also, it does this even if no source is playing (or even turned on) and also even if I select a source via the knob that I have nothing hooked up to. Therefore, it cannot be the source or anything upstream of the preamp. The only thing I haven't changed is the speaker wire (Kimber 4PR). I am going to put my old preamp back inline today and I expect that the pop will go away. Do you think this could be a bad tube? I figured I should probably talk with BAT on Monday, but I just got finished e-mailing this to the seller here on Audiogon and I wanted to post a similar reply to the forum to see if anyone might be able to help.

Thanks!
-Marc
mre2007

Showing 2 responses by mre2007

Smeyers: Would you mind contacting me after you get the diagnosis from BAT? It could save the preamp a trip if it ends up just being tubes.

I'd really appreciate it!

Any other ideas?
Well, here's my take. I taked to BAT and the suggested swapping the 6V6 tubes, as the pop is only in one channel. They said if this doesn't help, try taking the two 6922 tubes from one side and swapping them to the other side.

Well, I tried both suggestions to no avail. I'm supposed to call back to BAT tomorrow and get a RMA number from them to send the unit in.

Now, my unit doesn't have any oil caps in it, unless I'm mistaken, so maybe my cost will not be as bad?!

Now the real question, should I expect the seller to share the costs with me? He said that the unit was from a customer of his, and it wasn't exhibiting any problems; the customer just wanted an upgrade. I'm not sure I could file a claim with UPS... could I?

Thanks guys for your quick and helpful advise (as usual)

-Marc