[Amps] HELP Modifications for a Kenwood TL922

[Colin Lamb]

Hello Jean:

I see the problem as follows:

You got an amp that uses two 3-500 tubes, but you only got one 3-500 tube.  An additional 3-500 tube would cost more than the amplifier and you want a cheap solution.  

You can use two 4-400 tubes ore even 4-250 tubes and should be able to trade one 3-500 for two of those tubes.  In Europe, there are QBL equivalents to the 4-250 and 4-400 tubes.  The tubes will fit in the sockets.  These tubes are tetrodes, but the socket will ground both the screen and the control grid.  These tubes like higher voltage and will not run as much power - but they will work.

73,  Colin  K7FM