Do all tube preamps leak DC?

Talk to them, I am not sure how their caps are arranged, and it's most likely that these caps are in addition to the main cap. There's no way I'm aware of to make a single-ended preamp without a blocking cap. :)

The voltages inside the pre are around 300V and would easily fry electronics expecting a maximum range of +- 2V.  This is part of what a DC blocking cap would prevent.

Like I said, if in doubt, measure and listen.

Best,

Erik

So I just found a picture of the guts. As expected, it has two very large caps and a relay at the output. :) I think you are all set, but caps do fail, film caps VERY VERY rarely, so by all means, spend $20 on a multimeter with 100mV resolution and you can see it yourself. :)

If you measure any DC offset at all (relative to connecting the meter’s pins together) then contact the amp maker and ask them if it’s within tolerance.  Remember to use a 30K to 100K resistor while measuring, as this will be more realistic than the voltage across an open circuit.

Best,

Erik

The AI preamp have a protection circuit that will not allow the unit to output if there is excessive DC at the output. I wouldn't worry about it. Just use the basic protocol. Amp on last, amp off first.

I have been running Audible Illusions preamps (Modulus3, Modulus3A, and Modulus3B) for years into 3 different power amps, 2 Classe' amps and an Odyssey and never ever had a problem.  My only gripe is the preamps have too much gain!!!

Thank you Erik & paul79 for your input, I'm feeling better with this combination already. Although 6 Moons considers the Job 225 has set very high standards & his first listening tests with a tube preamp was one of the cons as he was getting some crackling sound which suggested that there was some DC leakage and quickly switched to a ss preamp. He also thought  Job should consider DC servos in the future to correct this. This is why I was somewhat concerned.