Has anyone done an evaluation of the tone comparison. I am sure most of you will know but in the 40's they came out with loctal tubes which were basically the size of octals but had a center post which kind of locked the tube into the socket. It was used extensively by the U.S. Military and car radio manufacturers used them as well because they don't vibrate out of the sockets. They pins are thin like a 9-pin mini. Some radio companies went almost exclusively loctal like Philco which I can attest to being that I own several philco radios dating from the early 30's to the early 50's. That said the 7C5 is supposed to be a 6V6gt in a loctal base. I happen to have a bunch of loctals because I restore radios as well as build guitar amps. I bought a "lot" of tubes which was mostly NOS loctals a couple months ago which had 6, 7C5's so you know I had to play. I built two adapters from Chinese ceramic loctal sockets and since I have a bunch of metal tubes many of which are dead or damn near, I extracted the bottom disc which housed the pins. I de soldered the wires which were imbedded in said pins and went to making adapters. FYI if you go to Home Depot or the like you can buy what is called a 1" EMT set screw coupling which is used for connecting 1" metal electrical conduit lengths together, it turns out the base extracted from the metal envelope tubes as well as the Chinese loctal tube sockets both fit snuggly in 1" EMT set screw couplings. Once wired together and a few drops of cyanoacrylate glue I had some quite sturdy adapters albeit a bit tall. I tested them all and matched pairs as best as possible and plugged them in to my latest amp build based on the National Valco 1224 Tremotone amp. BTW these 6 NOS tubes are all JAN/Sylvania from 1944. I tried them against a few pairs of 50's Sylvania chrome top 6V6's, 50's RCA's smoked glass, Metal RCA's, 50's National Unions. They are supposed to be 6V6's with a slightly different base but they sound quite different. Has anyone done a similar experiment? I am curious of the findings of others.
Topic: 6V6gt vs. 7C5 (Read 2352 times)