MCINTOSH 640 tube type RK-4D32 I had to do some digging and ultimately had to go to Sidney Corderman, VP Eng., to get some info. Those amps … | オーディオ, 音響機器, テクノロジー
4D32 SE AMP
4D32 SE UL amp
Pin di Ip-camera Wifi su Tube amplifier | Elettronica
LOT 32 PCS CASE NOS Raytheon 4D32 Tubes Collins, Hallicrafters, transmitters $480.00 - PicClick
Airpower LX-4D32 Special Edition Amplifiers - Thivanlabs
Raytheon 4D32 vacuum tube septar based transmitting tube - Etsy Italia
PAIR - RAYTHEON 4D32 TUBES f/ HAM RADIO TRANSMITTER / AUDIO AMPLIFIER | #1847188318