I am going to break down that Fryette quote by saying that he is listing the quiescent power dissipation of those amps. I have measured the output of a 5150/6505 and they do indeed pump out 44Vrms, and with a 16 ohm load is actually 121 Watts. The 5150's rating however it the quiescent power dissipation when it has been bias modded to 35mA, the most recommended bias point when a bias mod has been done. Stock they tend to run as low as 24W, key word, "as low as". Unless the Fryette Amps are Class A, there is no way his amps have that much more power over the others. Sounds like a way for him to get people into buying his amps, after all he did loose his company when he defaulted on his loans.
As for the 100W load, it is fishy, most tube amps begin to deliver full power at very low master settings, and a 5150 will send the full 120W to the load as low as 4 on the post, higher than that you just saturate the power tubes and eventually the phase inverter. After about 1 on the post, about 90% of the power is being delivered to the load. Now that is not necessarily bad, most product's wattage rating is not when it will blow up, but a certain percentage of the maximum failure dissipation rate. The speaker may be able to handle 120W, it may not blow up until 130W. The issue is that if you are going over its rating, you are reducing that products life. I know there are guys around here that use the tonehound and have no problem, but plugging in a device to a unit that can pump in more power that the unit can take is not smart, even if you will not push it to full power.
My recommendation would be either my loadbox or the Weber Mass 150 or 200, my loadbox has a resistive load but does not need a mic pre where the weber mass's line out option is currently unavailable. The Weber is a little more, but they are both in the same price range as each other and the tonehound. As for the line out option being unavailable with the Weber, you could email them and see if they will add it onto yours when it becomes available or if they can swap you out with one that does. That would be the best option if you had the slight extra dough for it.
