I'm running a DACGEAR LDR Pre Mk2. My Abbas Audio DAC and phono stage both have quite a high output level so an active isn't needed. Output impedance can be set on it I believe via settings.
I understand impedance should be set quite low for the Pass amps though don't know what is optimal.
I got the same amp as @joshnich though it's with a mate for a full recap and painting the front and top panels metallic black in automotive 2Pac. The sides, back and bottom will be left naked aluminum as will the screws and power button.
Supposedly its sound has improved significantly already with work done. A combination of Mundorf and Nichicon Muse electrolytics + Russian silver micas.