Hi sparkle, welcome to the forum
If you're used to 100W of tube power into a 16-ohm cab, then you should probably consider a SS amp that can deliver 500W-600W (bridged) - or more - into 8 ohms. The reasons for this are two-fold.
First, with SS power, you'll definitely want lots of clean headroom. To match a tube power amp, a rule of thumb is "Five times the tube wattage, for solid-state." This is not because tube amp watts are any 'louder' than solid state watts -- a watt is a watt, no matter where it comes from. It's more because, when overdriven, tube power amps ease into a musical type of harmonic distortion, whereas solid-state amps exhibit nasty-sounding distortion when they are overdriven. Five times the power ensures that the solid state amplifier has plenty of headroom to handle musical peaks, without ever going into overdriven states or producing any nasty distortions. Tons of SS power will give you the air-moving *THUMP* that you're used to feeling.
Second, most SS amps are power-rated into 8-ohm loads. Now, you can certainly drive a 16-ohm cab with a SS amp that's rated at 8-ohm, because most SS amps have no output transformers that require impedance matching. However, if you double the load impedance (using a 16-ohm cab instead of an 8-ohm cab), this will roughly halve the amp's effective output power.
So - If you're used to the volume levels of 100W of tube power into a 16-ohm cab, then look for a SS power amp that can deliver 500W - 600W (bridged) into 8 ohms. The good news is that powerful SS amps of this size are generally both
much lighter (and less expensive!) than comparable tube-powered amplifiers.
If you need to have a 1U solution, take a look at the ART SLA2 - 560W (bridged) into 8 ohms. If you can handle a 2U solution, there are several good options available.
