The cathodes of the 6L6GC tubes were connected to ground through the heater pins of the two 12AX7 tubes! The heating of these tubes (roughly 12.6v x 2 = 25.2v) were what provided bias for both 6L6GB output tubes. The output stage of the Airline 9005 has quite a unique design – the 6L6GB power tubes did not have a fixed bias OR a cathode bias. The two metal chassis are connected by a shielded cable carrying the audio signal path and by a multi-pin connector carrying high DC voltage, vibrato connectors, and part of the cathode bias design. The lower chassis contains the power supply, the output stage, and the vibrato circuit. The upper chassis contains the inputs, the preamplifier, tone stack, and vibrato controls. The first unique aspect of the design is that the Airline 9005 amp has two chassis. The schematic for the Airline 9005 amplifier reveals several unique design features: 1. The upper chassis was moved from the back of the amp to the front.The owner said it was not working and wanted to see what could be done to bring it back to working condition. I recently got one on the bench – however, it had been re-cased into an ill-fitting, pleather-covered, plywood and MDF board case. This is the Airline 9005 amp as I received it – having been installed into a new cabinet. An image of an Airline 9005 in pristine original condition I found on a selling site. The original case for the amp looked super sweet. I’ve seen examples with two 12″ speakers and one 12″ speaker. The Airline 9005 guitar amp was sold by Montgomery Ward’s in the early 60s.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
May 2023
Categories |