Dynaco ST-70 totally restored vs Dynaco ST-70 Kit

A dissenting opinion. I would go with Bob Latino's kit. The power transformer is beefed up over the original Dyna transformer, being a 5 amp job, the input board is the all triode Tube4Less board with individual bias for each tube (I prefer fixed bias to cathode bias). All the parts are new, many being American made. Basically, this addresses the weaknesses in the best selling amp of all time and makes this classic great for everyday use. I would also point out that all of the parts are available, most from multiple suppliers, so that should your Dyna break, now or in 20 years, there will be constant support for the amp.

I would agree and disagree with Amadarae. The original Stereo 70 power transformer, runs very hot and this bothers some people. On the other hand, as he points out, many of these are fourty years old and functioning perfectly.

What the original design does not take into account is that the aftermarket driver boards that are so popular, add the filament current draw of from one to five extra small signal tubes. This additional current draw can certainly put stress on the transformer beyond the design envelope. Some of these boards use octal drivers like 6SL7 and 6SN7 that are particular current hogs. And yes some original transformers can last another fourty years with even the added current draw of additional tubes. And, of course, if you have converted B+ rectification from the 5AR4 tube to solid state rectification than you have decreased the current draw on the transfomer.