4Pin Gold Chassis Ceramic Vacuum Tube socket, for 300B, 811, 2A3 – elecify
File:Pair Of Vintage Klangfilm Globe Shape Vacuum Tubes With 4-Pin Base, KL 71403 Triode D.R.P. (Deutsches Reich Patent) (L) And KL 76303 Full-Wave Rectifier (R), Made In Germany (34577535762).jpg - Wikimedia Commons
Lot of 5 -- Vintage 4 Pin Vacuum Tube Bases | eBay
TUBE 845 X2: Electron tube, directly heated triode, 4-pin, matched Pair at reichelt elektronik
Electronic Valve - Mullard, Triode, Type ORA, London, England, circa 1923
JJ Quad 12AX7 Gold Pins | vivatubes.com
VACUUM TUBE PINOUTS
Amazon.com: Fosi Audio 7-Pin 5654W Tested/Matched Vacuum Tubes Substitute for 6AK5 6J1 6J2 6J1P EF95 Preamplifier Tubes (2PCS) : Electronics
Popular Preamp Tubes | audioXpress
File:Vintage Philips E424N Triode Vacuum Tube With 4-Pin Base, Made In Netherlands (34739369305).jpg - Wikimedia Commons
How Tubes Work
Amazon.com: Riverstone Audio - Tested/Matched Pair (2 Tubes) 7-Pin JAN 5654W Fully-Tested Vacuum Tubes - Upgrade for 6AK5 / 6J1 / 6J1P / EF95 - JAN 5654W Platinum Grade Pair : Electronics
EIZZ 4 PIN PTFE valve Tube socket base Gold plated 300B, 2A3, 811, 274A, 5U4G - Audiophonics
4 Pin Vacuum TUBE SOCKETS Vintage AMPHENOL USA Steatite Ceramic 572b 811a 100th | eBay
RCA etc. ONE (1) Type 30 Triode Amplifier Antique tNOS AT1000 TESTED Vacuum Tube Nickel Plate Audio 1930-1943 | Reverb Belgium
VinylSavor: May 2022
TUBE WE300B X2: Electron tube, directly heated triode, 4-pin, matched Pair at reichelt elektronik
Vintage *RARE* NOS Cunningham CX-12 Triode Vacuum Tube, 4 Pin, Original Box | eBay
List of vacuum tubes - Wikipedia
File:Vintage Klangfilm KL 75301 Vacuum Tubes With 4-Pin Sockets, D.R.P. (Deutsches Reich Patent), Full-Wave Vacuum Rectifier Tubes, Made In Germany (33896321524).jpg - Wikimedia Commons
EIZZ 4PIN Tube Socket PTFE Golde Plated For 2A3 300B FU-811 811 274A 572B 5Z3 5U4G Vacuum Tube Amplifier Audio Vintage HIFI - AliExpress
Tube Base - 4 pin, ceramic, 1.25" diameter | Antique Electronic Supply
Tube socket - Wikipedia
RCA etc. ONE (1) 5Z3 Rectifier AT1000 TESTED Vacuum Tubes Hanging Filament 4 -pin 5U4G Audio 1933-1950 | Reverb
EIZZ 4-Pin Vacuum Tube Socket Base For 2A3 300B 40 45 50 5Z3 811 101D 24K Gold Plated Brass Pins Hifi Vintage Tube AMP DIY 1PC - AliExpress
