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 chotdavid

The exact same thing happened to me with my VK-30SE. I changed the tubes but that didn't cure it. I e-mailed BAT and described the problem and Victor e-mailed me back saying the most likely cause is a six-pack module that developed an electrical leakage. He said most likely the two modules will be replaced and the cost is $600.00.
Keneallyfan,

Yes, $600.00 to replace the two modules. The quote came directly from Victor Khomenko of BAT. Read the ff e-mail from him:

"Hi,

Most likely the output cap/caps developed electrical leakage and need to be replaced. Usually in such case both SIX-PAK’s should be replaced.

Regards,

Victor Khomenko

2nd email below:

"The whole job cost $600. We replace the complete modules. You may keep the old modules, as those caps are great and can still be used in many projects. Out of 12 caps there chances are a couple are leaky, the rest might still be fine."
-Victor

Keep in mind that this is his analysis of what might be the cause of the loud pop when muting. It might turn out to be something different/more when you ship the unit to BAT.