Alamo Amp-2

[Jersey Jeff]

I just picked up a small Alamo Amp-2 (1950-ish). The output transformer is gone. Any idea about what size transformer I should replace it with? The amp drives a Jenson 8" "Alnico 5" speaker. Tubes are 5Y3, 6V6, 6SN7.

[Cliff Schecht]

Any Champ replacement output transformer will work. The transformer should be specifically for single-ended amps, have a 5k or 7k primary and have a 5W rating. The one sold at Triodestore (by Magnetic Components) is cheap and would work well.

Also measure the resistance of the speaker with a multimeter set to the low Ohm measurement setting. If the speaker Ohms out to below 4 Ohms then it's a 4 Ohm speaker, if it Ohms out to above 4 but below 8 then it's an 8 Ohm speaker. Make sure the secondary of the output transformer you buy matches the impedance of the speaker in the amp.