[Amps] Why 2 3CX800s instead of one 8877?

[Colin Lamb]

I am somewhat mystified by the messages.  The Alpha 76A has 2 or 3 tubes 3CX400.  But there is a difference.  The 3 tube version you can plug one socket and then use 2 3CX800A7 tubes.  They fit fine.  I changed one and mounted the transformer inside the unit.  It works fine.

There is a problem with the two tube version.  If you change to tubes to 2 3CX800 tubes - the sockets are too close together so they do not fit.  That would require more work because the holes and all the chimenys are too close together.  I have a 2 hole amp and used the 3CX400 tubes.  I run that amp at 1200 watts and it has run flawlessly for years.  

I did a couple of other things to my amp.  I installed a vertical array inside between two meters for grid response.  Because these LEDs are much quicker that the meter it is much faster and that lets me monitor forward output with the meter.  Then, I converted the output meter to read peak reading with a meter used for the Bird Wattmeter.  I have about 6 amplifiers and with those two changes this amp is the one I use day after day.

73,  Colin  K7FM