Please note that our Support Department is closed on Saturdays and Sundays. It is possible that the power strip you are using could be the culprit, however if you are connecting in the TimeFactor in front of your amp and within the FX loop of the amp (and your amps loop isn't buffered), the TimeFactor is acting like a buffer that is allowing high frequencies to be present that are lost when not using a buffer. Alot of amps have FX loops that are buffered but oftentimes vintage or boutique amps will not, so to combat the problem you are experiencing placing a buffered pedal before the TimeFactor will alleviate what you are experiencing. You may also select DSP Bypass mode as another alternative.
Your TimeFactor's serial number has the shield including from the factory.