Gotta make a responsible choice and sell this .

I need at least 1 business day to box it up before shipping. I prefer to use USPS for shipping in the US only.

Cons:

• One thing to be aware of that is the case with all Beta 22 amps is that you need to lower the volume all the way before unplugging or plugging in new headphones or you could fry a part of the amp.
• I would never use this amp for Planar headphones, doesn’t drive it to a satisfying level imo. Word on the street that it drives the old Audeze headphones great though.
• It’s pretty big since it is 2 unit

Pro:

• It’s really clean sounding
• Drive my AKG K240 Sextett EP at 600 ohms at a great level, so this would go great with your high level dynamic headphones
• Black Background when I using it in my streamer setup (no computer in the audio chain) even with my low ohm Onkyo A800 (32 ohms)

What it comes with, Beta 22 Amp, Sigma 22 Power Supply, Umbilical Cord and power cord.

1st owner for pics of the inside: Closed: Rockhopper Audio Beta 22 Global Voltage | Headphone Reviews and Discussion - Head-Fi.org 1

Who the 2nd owner was: AMB B22 / Beta22 headphone amp built by Rockhopper Audio For Sale Or Trade - US Audio Mart 1

Official website: https://www.amb.org/audio/beta22/