Source
SW1X Universal Music Server UMS I Signature with Power Supply Unit PSU I Signature
SW1X USB II
SW1X DAC III Special
Audiolab 6000 CDT transport
Amps
Pre amps -- Hi fi Collective twin mono ladder stepped attenuator, with Charcroft Z-foil and silver wired. And First Watt B1 active no gain buffer.
Power amps -- Welborne 45 SET monoblocks 1.8W / Decware Taboo 6W / Elekit 300B TU-8600SVK plus further improved components 9W / ICE Power 1000W
Speakers
Highly modified Endorphin P17 open baffle speakers containing both vintage and modern alnico drivers and paper cones. All silver wired - 8" Cube Audio FC8 full range drivers and vintage 15" Altec VOTT 416 bass drivers. All sat on Townsend Audio Podium seismic isolation platforms.
BK Electronics XLS400FF Sub.
Cabling
Silver mains cables, interconnects and speaker cables by SW1X
Headphones
HRT HeadStreamer and SennHeiser HD650 headphones
Location: Seaford UK
Posts: 1,861
I'm Dennis.
Your Passive pre is applying no amplification at all to the signal, it only attenuates.
No one seems to have asked what your source is, to be such a miss match for your power amp. it sounds like a very hot digital source.
What is it and what's it's output?
Is it a DAC with a digital volume control that can be turned down?
What is the input sensitivity of your power amp?
Adding resistance to your Passive Pre, might be the solution, but alternatives, or even defining what the actual problem is, has not been given proper consideration.