What is the most likely cause of low level (but still too much) hiss/static?

[wrxplayer]

I''ve got a great sounding amp used but there's a low level (but still too much) hiss/static when it's on. The hiss gets louder when I turn up the reverb but is there even if the reverb is not engaged. What is the most likely cause and best first step in troubleshooting?

The amp is a Blankenship Fat Boy with Sour Cream head + 1x15 cab. Tubes are 2x6l6 for power tubes, 2x 12AX7 2x 12AT7 5AR4 rectifier tube.

Hiss is present w any guitar or no guitar.

This is the exact amp but played by someone more talented than I.

For those want lots of info, here's a demo of the amp as well as a gig with my exact amp (but not me playing).

 

[Blue Strat]

Preamp tubes, especially the ones associated with the reverb, are the ones to look at. Swap them out with known good tubes as a first step.

 

[axpro]

I had the same issue with a DrZ Maz8, I like the amp, but there is some hiss... If i pull the reverb driver tube it goes away, but that messes up the sound of the amp sadly. Unless it is amazingly well constructed, I find all reverb amps have a little bit of hiss associated with them... thus i tend to buy/build non reverb amps lately. with the Maz, I tried swapping out tubes and such and it got better, but never perfect. Part of that one may have been that it's a single ended amp, they tend to have a little natural hiss as well.

So try some good quality tubes, if you are able, try moving the reverb tank or just the associated wires.

Let us know your results!