Transformer coupled outputs for a dac?

Quote:

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.

Just finished reading about Sheldon Stokes latest Dac.

http://getinthewoodchipper.com/?p=302

I am listening to the loaner Neko Audio D100 Mk2  PCM1794A Dac with Jensen transformer output. This is one of the best sounding Dacs I have ever listened to. Period. THE best actually.

http://www.nekoaudio.com/

Another place to find a schematic of an already implemented circuit using transformers would be www.kandkaudio.com

http://www.kandkaudio.com/schematics.html

Totally agreed with Nikongod. Throw the measurements out the window. Try something different, and simple, and listen for yourself.

Quote:

Originally Posted by nikongod 

I got different ratio transformers (originally 10K:600, now 2.4K:600)...

Just curious, why are you using step-downs?

Also, there's the transformer-as-passive-I/V-converter approach for current output DACs.

se

Quote:

Originally Posted by Steve Eddy 

Just curious, why are you using step-downs?

 

I dont need as much voltage swing as the DAC chip puts out, so I figured Id trade it for long-cable driving and the ability to run a whole bunch of amps at meets. 

Quote:

Originally Posted by nikongod 

I dont need as much voltage swing as the DAC chip puts out, so I figured Id trade it for long-cable driving and the ability to run a whole bunch of amps at meets. 

Ah, gotcha.

Thanks.

se

^when he's not borrowing signal from other folks....

You had to bring *THAT* up. :facepalm: 

The Zhalou actually works with The Silver Ghost now. 

Yes, well, there is only so much equipment one can carry in a suitcase.

I wonder if anyone would like to take a stab at the worthiness of amorphous, or other types of, transformers that could be used in this situation. 

Experiences. Even if by friends.