[gyrodec]

I'm thinking of driving my HD600s directly from a DAC/Sound-card - likely candidtaes are either Asus ST/STX of Cambridge Dacmagic (not decided yet, and not important for this question). In either case I can easily get at the balaced output signal, and would just need to amplify the current abilities and perhaps the voltage a bit - i.e. I need a buffer (with possibly a bit of gain).

Does anybody have any suggestions as to what might be the best? Obvious candidates include: TP Ventus, JISBOS or one of the diamond buffers (per Anders still sells these, I'm not sure which other versions are still around).

Small packaging and low idle current draw would be nice as I'm going to the stuffing them where they weren't supposed to go, but I can work around those issues so they are a nice-to-have.

Thanks for any suggestions.

 

[audiowize]

You might start by trying a pair of 600:150 ohm matching transformers at the output of the DAC before adding active electronics.

 

[gyrodec]

audiowize: Thanks for the reply, but isn't that going to leave me a little short on current, or volatge, or both? The filter stage of the DAC will be 2v max and very little current capability as it will be a standard op-amp. As a transformer can only trade current for volts, or vise-versa, and I appear to be both current and voltage short, how will the transformer help?

 

[Steve Eddy]

Quote:

Originally Posted by audiowize /img/forum/go_quote.gif You might start by trying a pair of 600:150 ohm matching transformers at the output of the DAC before adding active electronics.

600:150 would be a 2:1 step-down. He's wanting to get a little bit of voltage gain.

se

 

[Steve Eddy]

Quote:

Originally Posted by gyrodec /img/forum/go_quote.gif audiowize: Thanks for the reply, but isn't that going to leave me a little short on current, or volatge, or both?

Yes.

A 600:150 transformer is a 2:1 step-down.

While it would reflect your headphone's impedance by a factor of four, making for an easier load, it will also reduce the output voltage of your DAC by a factor of two.

In other words, no power gain.

However what you could do is use a 150:600 transformer to drive a unity gain output buffer. The transformers will give you a gain of about 2.

se

 

[gyrodec]

K.I.S - Thanks: Thats what I thought. Not really going to have room for trannies in this application though.

Does anybody have any feelings on the relative merits and sound quality of the suggested buffers, or have a better idea?