[Dougigs]

Another interesting option is Ron Welborne's remote-control stepped attenuator ( http://www.welbornelabs.com/remote.htm ), which is available in a balanced version.

It's essentially the same as a relay-based attenuator (several of which are available in Asia, such as from www.diyclub.com ), but uses a digital potentiometer for the "shunt" leg of the attenuator (the "pass" leg is a high-quality resistor of your choice).

Audio-wise, this is a very high-quality solution (also allows you to change the basic impedance fairly easily) -- I picked one up and put it in one of my systems, and it's extremely nifty. The remote-control aspect might not be such a big deal for headphones, but it also has pushbutton control and is small enough to fit into a smallish chassis.

These sorts of attenuators do present a varying input impedance (as do some of the ones you've discussed above), though not as wide a variation as you might think... it's worth making sure you have a parallel resistor of at least 10X your nominal impedance to keep things more constant... but you also have to be a bit careful with any input capacitors and make sure you're not creating a variable filter...

I'm still not completely wedded to attenuators, though.... for headphones, I really like the continuously variable nature of a good potentiometer.... I like to 'ride' the volume control, and don't like the clackety-clack of a step attenuator. I'd like to hear what you folks think of the tradeoff of gaining sonic benefits vs. losing tactile pleasure when switching to an attenuator. Also I'm not really sure that the audio improvement is all that great. One thing worth playing with is lower-resistance potentiometers... there's a very interesting thread currently taking place over at headwize on the audio merits of 10K pots.

 

[Dougigs]

(duplicate post)

 

[Pars]

Quote:

Originally Posted by Dougigs <snipped>I'm still not completely wedded to attenuators, though.... for headphones, I really like the continuously variable nature of a good potentiometer.... I like to 'ride' the volume control, and don't like the clackety-clack of a step attenuator. I'd like to hear what you folks think of the tradeoff of gaining sonic benefits vs. losing tactile pleasure when switching to an attenuator. Also I'm not really sure that the audio improvement is all that great. One thing worth playing with is lower-resistance potentiometers... there's a very interesting thread currently taking place over at headwize on the audio merits of 10K pots.

Those digital controls at Welborne look interesting, as well as whatever sft is using in his Dynahis. I would agree that the continuous nature of a good pot is more to my liking (although I have never used an SA in my own stuff). I am really pleased with the TKD pot I am using in a Dynalo and the Penny and Giles that I tried in Kevin Gilmore's personal Dynahi at a meet was really nice... I may have to try an SA at some point just to see for myself.