The H-Cat suggestions are worth looking into, particularly if you are looking to "wake up" a system. It may not be the answer if the system sounds too hard or in-your-face. It is not that the H-Cat is itself hard or harsh, but, it may be too revealing in some systems.
From a practical perspective, if you keep your amps on all the time (I would with high power solid state because such amps need a lot of warmup time to come on song), you would have to also keep your linestage on all the time or at least have a stage which mutes output when it warms up to avoid turn-on sounds from the linestage feeding a power amp that is on. This could eliminate some tube linestages from consideration.
From a practical perspective, if you keep your amps on all the time (I would with high power solid state because such amps need a lot of warmup time to come on song), you would have to also keep your linestage on all the time or at least have a stage which mutes output when it warms up to avoid turn-on sounds from the linestage feeding a power amp that is on. This could eliminate some tube linestages from consideration.