Shown in the photograph are a pair of DIY Monoblock KT88 Push-Pull Tube Amplifier Kits. See the review for additional details of this great sounding tube amp kit. Also shown in the photo is a NAD C521i CDP used a transport and a Behringer SRC2496 which is being used as an up-converting DAC. The little black box is a DIY Lightspeed (optocoupler) Attenuator.