This is a lot of 24 viintage EECO tube circuits. About half of them have the tubes installed...typically a 12AU7-type. I dis-assembled one to show how they're constructed. There are several types of circuits here: Squaring circuit; Multi-Vibrator; Thyratron Ring Counter; Gate Amplifier; Pentagrid Gate; Dual-Transfer Gate; Flip-Flop; and Relay Flip-Flop. These would be great for hot-rodding a tube amp, building a tube computer, or experimenting with tube circuit designs. Another good application would be to use the sockets to buid adapters to use low-wattage tubes in place of 6V6 or 6L6 output tubes...so you can hear that wonderful sound of overdriven tubes without scaring off the neighbors!
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