Alamo Electra OT question

[mojoworker]

hi -

i am working on an Alamo Electra tube amp. i dont know the impedance load, because the speakers have no markings and are nonfunctional with no continuity, so they can't be measured.

tube layout is: 2x 6V6, 5Y3 rect, 3x 12ax7, 7199 PI
OT is stamped Z 3322

i uploaded some photos of the OT and a sketch of the signal path here: Pictures by langlieger - Photobucket
the wire that appears grey is the same as the blue one inside the chassis (just discolored).

if i understand the signal path correctly, using the extension speaker jack will not use both the amp speaker and the extension, but only the extension position. and it would switch to a different OT signal pole and thus change the expected impedance load.

can anyone help me out with the impedances i should use for these positions? or let me know if my signal path looks incorrect? is there a way to measure the necessary impedance otherwise?

any help would be greatly appreciated.

[Enzo]

I don't see a link in your post.

Is this schematic close to your amp?

http://www.webphix.com/schematic%20h..._montclair.pdf

You could laboriously calculate turns ratios and go from there. But in general 8 ohms is a safe bet.

[pinkjimiphoton]

i had a couple alamos over the years...all had 8r speakers.