What is this strange sound on my Fender Hot Rod Deluxe?

[StevenT]

I've fallen in love with the special edition; the one with the black sides, tweed top and the vintage 30 speaker. I can't seem to find one that works though; all the ones I've tried out make THIS terrible noise.

sound sample: HotRodDeluxeSE by StevenTrimmer on SoundCloud - Create, record and share your sounds for free

What's going on here? I'm on the clean channel with the bright switch engaged. It makes no sense, but the level of the drive (2nd channel) seems to affect how harshly it glitches. The first time I bought this amp the same glitch showed up too. The problem went away for a few days, but then the amp died halfway through a practice! The Fender authorized repair man couldn't get it to duplicate this problem; maybe he was just playing really soft or something. Anyhow, I returned that first one, and today drove to Atlanta and back to pick up another one only to find... the same malfunction! I'm really surprised to get two lemons in a row! I'm playing a squire jazzmaster; a little hot but nothing too crazy. Any input would be much appreciated! Should I drive it back to the ATL or have my amp guy take a look at it? Is it clipping the preamp somehow?

[Ngr]

it sounds like bad plate load resistors.
if you are not familiar with tube amps bring it to a tech.
the problem you have has nothing to do with clipping of any kind.