At least some of those in your pic appear to be OTC tube amps... (Output Transformer Coupled). These are still "true" tube amps but are not 'Output Transformer-Less' tube amps. Whether or not any of them are OTL/OTC/Hybrid can only be answered by cracking the case. Personally a cheap tube amp sounds like a good way to fry some cans to me. I would stick to Darkvoice/La Figueroa/Little Dot/Schiit/Bottlehead on the lower end of the cost spectrum. Woo, Rogue, Feliks Audio, Cayin and others on the higher end of that same spectrum.