Originally Posted by iamthecheese
Are transformer coupled outputs really significantly better than a good output stage with good op amps or discrete op amps?
Its a great idea. Let me (try) to answer the question then go on...
Define "better" Measurements guys are quick to jump on the fact that Active output stages DO measure better than transformers. BUT there is something simple & elegant about the whole thing.
Now there are some cool things going on with transformers that are harder to achieve with active stages. Mainly that transformers are EASY to make ground-loop-proof. They also go back and forth between SE and balanced very effortlessly. After that its really just following the "simpler is better" school of thought, which is not too hard to get behind.
Each school of thought has its advantages.
Unless Im reading the thread over there wrong they are using a Voltage output DAC chip, which has op-amps IN the DAC chip. Sorry to bust the bubble. The good news is that all the associated stuff around the opamps is (are?) matched to tolerances MUCH better than you could do with discrete gear.
A couple pics of my Zhalou 2.5a with Edcor output transformers:
I have made some changes since these pics were taken, but nothing major. I got different ratio transformers (originally 10K:600, now 2.4K:600) and added a simple RC filter network in front of the transformers to roll things off around 40Khz.