How can you find out how much the voltage swing is? Products specifications? Then most doesnt seem to show this.

Most amp publish specs by power output at specific load in ohms. You can derive the voltage/current required to drive a headphone. Here's the relationship between power, voltage, current and impedance/resistance Power = Voltage x Current = (Voltage)^{2 } / impendance = (Current)^{2 }x impendace HE-6 due to it's very low sensitivity needs more power than most headphone. It also has low impedance (50 Ohms) it will draw more current compared to a high impedance can like HD800 or T1. As a guide, look for an amp with low distortion (< 1% THD) and power output of at least 2Watts. That would translate to 10Vrms and a voltage swing of around +/- 14V. Most people use speaker amps for HE-6 so they don't have to worry about power output. There are only a few headphone amps capable of power output of 2Watts or higher. They are generally more expensive than equivalent speaker amps.

2W = (Vrms)^{2} / 50 Ohms Vrms = 10 Vrms = 0.3535 x Vp-p Vp = Vp-p / 2 Vp-p = 10Vrms / 0.3535 = 28 Vpp / 2 = 14 +/- Vp

So - am I calculating correctly if I get that a 50W (in 8 Ohm) speaker amp has 20 Volt? And this will be push-pull, not +/- ? This will be RMS Watts, so peak voltage swing may be larger - or what to expect? Edit: typo

I'm following everything else, but where does 0.3535 come from? That number has to be derived from something.

Playing around with sorbothane strips 40duro , I put 3strips each side mostly on front 1/2 of the cups , so far better .

cut each pieces in 4 little one near another ... 3 strips is perhaps better than no sorb. BUT no comparison with my mods... read my post on the sorbothane thread of Edstrelow (#post 289) i explain why and how to apply sorbothane...The difference is staggering between strips of sorb and strips cutted in little pieces....

read my post... i dont want to repeat all here.... And remember to report on the sorbothane thread also for the interest of all of us... Thanks and best regards

I am looking forward to trying the HE-6 with the Zotl 10. It will be 3 watts into the 6's of EL84 power. One of my favorite tubes.

It comes from 1/2√2=0.3535. http://www.physics.udel.edu/~watson/phys345/fall1998/class/6-rms.html the picture at the bottom pretty much explain your question. Details of the transformation require integration of sin^2.