Electrostatic & Dynamic amplifier

Keep in mind that any amp that can power both dynamic and electrostatic headphones is pretty much two separate amplifiers in a single box - there's really no practical way for them to share much of any circuit, except input selection.  While I can understand your desire for less clutter, that is the only advantage - in every other way, you're looking at simply purchasing two substandard amps for a substantial price. 

At my main residence, use  Manley neo 300b preamplifier as preamp/headphone amp/Stax amp.  it has more than enough juice for standard Lambdas.  007 might be dicey, have never tried them with Manley Neo 300b. At the headphone show, HE60s seemed underpowered with the neo 300b, but don't know if it was a good HE60 sample.

 

I use a banana jack adapter into the speaker leads of a Stax SRD transformer box.  Supposedly the headphone jack puts out about 675v rail to rail on the 100 ohm setting with a 25:1 voltage step up from the trannies.

 

That makes the Manley neo 300b preamp a three-way the way I use it.  Sounds wonderful with Stax Lambda, dynamic headsets and as preamp. Not a cheap component, but occasionally can be found used for 3K neighborhood.

Edited by cjfrbw - 9/28/12 at 11:34am

The problem with any one size fits all solution are the compromises just get bigger so it's the master of nothing. 

Technically you can just get a speaker amp and run everything from the speaker outs, I think (note I'm anything but an expert in electrical circuits).  Stax definitely yes since you've got the WEE.  Dynamics you're going to need a converter box thing that makes sure the amp sees an 8ohm load or something like that.  Hifiman has such a box for their HE6... I believe (note I have no idea about electrical circuits) if you just increase one of the default resistors they put in that box, you'll get more usable volume range for a normal headphone vs a super insensitive one like the HE6.  All presupposing that you're running the dynamics balanced to keep the -VE apart from each other unless your amp can handle that, I think.

 

I plan on doing the above with my large SET speaker monoblocks.  I'll definitely be able to do a Stax w/ the WEE, as well as HE6 from the hifiman box, though I'll have to check really quick if that hifiman box is suitable for running dynamics in general without getting too loud too quickly.

An interesting DIY solution would be a 2 or 3 stage transformer based amp. First stage would essentially be a garden variety "spud" amp using a high mu/high gm type tube driving something like a 5k:32 transformer. Dynamic phones are driven directly from the 32 ohm outputs. For electrostatics, the signal is taken off the primary of the first stage transformer and coupled via a capacitor to a large power tube like an EL34, the EL 34 is loaded with a large phase-splitting transformer which produces an electrostatic level voltage swing. Probably not small, certainly not cheap, but if done correctly, not necessarily compromised.

That could be done but a far cheaper way would be something like the RSA B-52/A-10 SRPP circuit.  They are essentially the same so just use a lower B+ and a large output cap for dynamics and then double the B+ and a smaller cap for electrostatics.  It will sound very poor indeed but aside from the high voltage switching gear it would be very, very cheap to build. 

 

There is a way to do this properly though so take a very robust SS amp (say Dynalo) for use with dynamics and then switch it to high gain and feed it into the back end of a KGSS for electrostatics.  The true challenge with any of this though is the high voltage switching as normal relays will not work. 

Another thought, that isn't a single amp, is just a relatively compact stack. Like the CEC HD-53 and the WEE. You'd have one volume control and input section, just different outputs. A standard stereo receiver + transformer for the 'stats would also work.

You could purchase something like the Antelope Zodiac DAC, which includes a dedicated headphone amp for dynamic HP's. You could use the DAC as a source to an electrostatic amp.

is there a post or wiki anywhere that explains how they differ?

How what differ?