tube pre amp and Krell FPB 600

I realized that this is an older thread but I am concerned. I've purchased a vk-3ix (have not received it yet) used. However reading Haroon's comment on how it fried his JC 1 because it doesn't have coupling caps concerns me because I have a A21, which is basically the baby brother of the JC. What I don't understand is this from the Parasounds Owner manual:

"Parasound power amplifiers incorporate ingenious and fast-acting DC servo circuits, which completely eliminate the need for coupling and blocking capacitors. The JC 1 is direct-coupled from its input jack to its speaker terminals.This advanced circuitry never needs adjustment or maintenance. It operates outside the audio signal path to keep the DC offset at the output of the JC 1 at a constant 0.00 Vdc.The results are startling clarity, freedom from listening fatigue, and formidable bass response."

In relation to the comment should I not use the BAT?

Have anyone have any experience upgrading the Krell input coupling caps ? Can you share your experience ?

Have anyone have any experience upgrading the Krell input coupling caps ? Can you share your experience ?

The input of the Krell is direct-coupled (no coupling caps). This is why they are 'concerned'. However, the claim that tube preamps put out DC is ridiculous. They no more do that than solid state.

With due respect to Ralph, I think Krell's concern about tube preamps being used with their direct-coupled amps is a valid one. Many tube preamps have a substantial low-frequency pulse on turn-on and turn-off which can cause major problems for a high-powered direct-coupled solid state amp. Note that these pulses occur notwithstanding a coupling capacitor on the output of the preamp. Most modern tube preamps have a muting relay which allows the preamp voltages to stabilize before the amp is connected. However, not all tube preamps have muting relays and Krell is understandably going to err on the side of caution. No manufacturer wants an unhappy customer.

Of course, Krell could have just warned that the power amp should always be turned on after the preamp has warmed up and turned off before the preamp. This simple procedure would also solve the thump problem, but then who wants to count on their customers actually following this advice.