World class construction, but no gold on XLR's
I was looking for a nice rack mount chassis to hold two 500 series modules. Since API quit making their 500R unit, this A Designs 500HR fills the void in the market for all of us folks who just need a two module rack mountable chassis.
The mechanical construction of this piece is top of the line world class, very sturdy, and superbly manufactured. The power supply inside the unit is the same supply A Designs uses in their Pacifica preamp. Nicely filtered and regulated providing 175mA per each + and - 16V rail. Note: Buzz Audio doesn't recommend using their products with this unit because of power supply noise, but the supply seems to be fine with most other 500 series preamps.
This 500HR would have received a 5 star rating from me if they would have used gold plated XLR connectors.
I recommend putting some Caig Labs DeOxit Gold G100L-2C on your new 500 series module pc board card edge connector pads prior to installation in the 500HR to prevent galvanic oxidation from forming between your module pads and the 500HR connector contacts.