Some have guide pins, but many do not, worse when present they are not necessarily in the right place. I would avoid using vintage sockets with 300B unless you are sure the pin is not going to cause an issue.
JJ300B have guide pins, but I am not sure whether or not they are in the same location as a reference WE300B - I no longer have any WE to compare..
JJ300B have guide pins, but I am not sure whether or not they are in the same location as a reference WE300B - I no longer have any WE to compare..
You are correct. The difference between the two types is that the pin is offset 45 degrees.
My JJ 300Bs have a black dot where the guide pin is supposed to be. It could be that later production has a real pin there (mine are around 15y old).
I remember the Chinese versions from the late 90s all had guide pins so they could be used in the (Chinese) twist lock sockets.
I don't think I ever saw such a socket in an amp though, only on the shelf in the shop.
I remember the Chinese versions from the late 90s all had guide pins so they could be used in the (Chinese) twist lock sockets.
I don't think I ever saw such a socket in an amp though, only on the shelf in the shop.
I built a DIY amplifier that used a 5Z3 - a 4 pin rectifier. During the initial build I used some cheap knockoff of the classic Johnson Ceramic socket.
I found that it was possible to insert the tube incorrectly, the tolerances of the small pin holes were loose enough that the big pins could slide in.
I ended up replacing the socket with an octal one and using the 5U4.
I found that it was possible to insert the tube incorrectly, the tolerances of the small pin holes were loose enough that the big pins could slide in.
I ended up replacing the socket with an octal one and using the 5U4.
Ha! I should have waited for your answers!
I did in fact insert 3 out of 4 Electro Harmonic wrongly (into a Chinese amp). Now 3 out of 4 test bad in my tube tester. When I plugged them back in, this time correctly, the channel with 2/2 testing bad plays low, the channel with 1 out of 2 testing bad, plays at higher volume.
I guess I'm in the market for some cheap 300b replacement then :/
I did in fact insert 3 out of 4 Electro Harmonic wrongly (into a Chinese amp). Now 3 out of 4 test bad in my tube tester. When I plugged them back in, this time correctly, the channel with 2/2 testing bad plays low, the channel with 1 out of 2 testing bad, plays at higher volume.
I guess I'm in the market for some cheap 300b replacement then :/
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