Oceanica1, if you already have a set of the ZEROs, just about any lower-powered OTL will be OK with the load of your Gallos (they aren't *that* hard to drive after all...).
A small OTL might make 20-30 watts, which is a lot of power for an SET. Our S-30 will make 45 watts into 16 ohms, which is what you will be loading the amp at with a set of ZEROs. I suspect that driving directly, the same amp would be bass-shy.
An added benefit is that most lower-powered OTLs will be a lot cheaper than SETs of the same power :)
A small OTL might make 20-30 watts, which is a lot of power for an SET. Our S-30 will make 45 watts into 16 ohms, which is what you will be loading the amp at with a set of ZEROs. I suspect that driving directly, the same amp would be bass-shy.
An added benefit is that most lower-powered OTLs will be a lot cheaper than SETs of the same power :)