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Help with Output Transformer
Help with Output Transformer
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Old 18th February 2012, 02:56 AM   #1
mojoworker is offline mojoworker  United States
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Join Date: Feb 2012
Default Help with Output Transformer

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.


Last edited by mojoworker; 18th February 2012 at 03:55 AM.
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Old 18th February 2012, 11:08 AM   #2
DF96 is offline DF96  England
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Join Date: May 2007
This is the power supplies section. Your question is about output transformer wiring.
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Old 18th February 2012, 11:21 AM   #3
wintermute is offline wintermute  Australia
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Help with Output Transformer
moved to tubes forum.
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