I am getting ready to construct a headphone amplifier and I need a little help finding good output transformers for the circuit. "I will say that the type of transformers I get will likely dictate the type of amplifier I end up constructing as well. I was really hoping to construct one that uses a 274B and either 6BQ5's or 6DE7's." After searching the web, I can't seem to find a good source of headphone friendly output transformers anywhere. Are there any ones under $100 "though I could possibly go more?"