Tube Audio Design TA-60 schematic

Not only the same, but vast majority of amateur DIY tube amps have the same circuit diagram.

A 50W 100 ohm resistor in the power supply?????

Marakanetz, "Not only the same, but vast majority of amateur DIY tube amps have the same circuit diagram."

Absolutely correct.

So do the vast majority of commercial tube amplifiers, as it's the dominant topology, inherent in all but a small number of other products. This makes me raise an eyebrow when companies or their principals/fans claim they have something unique regarding their circuitry.

I emailed Edmund Lam a few months back regarding schematics for the Tad 1000's and he kept refering me back to Paul. After finally grasping the fact Paul had passed away he offered to sell me the schematics for $100.00 and now I see they're also on the website.

There is nothing unique about this circuit, in fact I take issue with the 50W resistor in the power supply. It's a bit obvious they went with some power transformer that was off the shelf instead of having one made to their spec. If there was room I would of used a choke not a resistor. I would not spend $10.00 for that circuit diagram. There are plenty of good designs out there. I also would not use their output coupling transformers either. I would try and find one made here.

Besides trivial amateur circuit design people pay a lot extra for the name when they can get around with Jolida instead for much less.