Krell S300i Volume Control Popping Noise


Recently purchased from a dealer, adjusting the volume control up or down makes a popping noise through the tweeter, which I can hear even with music playing. The dealer swapped for a different unit, which still pops, but not all the time. The old unit popped all the time. Not only is the pop annoying, it's a borderline concern for tweeter safety. I called Krell, long story short, was told that, yes, it pops. Speakers are JMlab Electra 915.1, and other equipment includes Musical Fidelity A308cr pre, power, and CD player, and Oppo BDP-83. Interconnects are Cardas, speaker wire is homemade, but also subbed in Monster Cable to no avail. In addition, I get more tweeter hiss with the Krell than through the Musical Fidelity gear. These quirks are not commensurate with my idea of a high-end product. I previously owned a Krell KAV 300iL, and do not recall having this issue. Thanks in advance.
readargos
Thanks. I suppose it could the the power line. I'd have to try another location to verify. I was told early production units had a loose ground, and wondered whether that could impact the volume. A UK forum contributor found the same issue, calling it a clicking, rather than a popping, sound (but I have no transformer hum, as he reports).

http://www.harbeth.co.uk/usergroup/showthread.php?41-Harbeth-SHL5-specific/page13

The Krell integrated was noisy in operation, it seemed to use the same numeric volume control as my Arcam pre, but with an audible click with every change and it hissed through the speakers worse than a Naim pre, plus there was a very noticeable mechanical hum
My Krell s300i of almost 7 years started having problems with the left channel.  Lots of static and popping noises came out of the left speaker.  The problem became progressively worse until I heard them even during very loud passages.  I had to remove the unit from my system.  Krell said it was either something loose in the left channel input, or the left channel board is defective.

Of course, it was out of warranty.  And if it was a bad board, what about the right channel?  Diagnostics will run me around $150 plus shipping back and to Krell.  Who knows what the materials and labor will be to actually fix this.

The unit also produced hissing sounds that were noticeable when the system was at rest.  The hissing plus the problem with the fore mentioned popping sounds are not what I had expected with a high end unit.  Pretty disappointed.  

I have replaced the Krell with a pair of Parasound classic power amps bridged to mono amps.  Super quiet, and quite musical.

The defective Krell is sitting on the floor.  I'm not sure I want to pursue repairs because it is possible the right channel will eventually have the same issues.  Plus I'm not crazy about reinstalling the amp hisses.  Which means the alternative is to junk it.  Again, disappointed.
Given the age of this thread I imagine that no one will notice...My 10 year old Krell S300i is experiencing similar problems. The volume dial stopped working several years ago & over the past year it started emitting low volume RFI mostly through the left channel. Perhaps my imagination but it doesn't sound as good it used to. I feel like I've checked everything from cables to using it in a second system. Any comments appreciated.

yes very old conversation but my s-300i did the same thing so bad I took it out of my system but the other day pulled it out opened it up and noticed that the rectifier on the end of the board by the capacitors was a very bad solder joint where  the KBJ2508 could not have been working right so pulled it out (the whole board) took the heatsink off redid the thermal paste resoldered the bridge and it has been working now going on 5 hours  it is what it is till its not