The Harmony 420

The Harmony 420

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Harmony H420.


Harmony 420. The chassis is mounted in the rear 'tweed style.' This mounting style is different from any of the other amplifiers in the similar amplifiers category. The output transformers that I have seen have carried the same T3778 part number as those used on the S6420 Thunderbolt. The power transformers also carry the same number as is found on the S6420 Thunderbolt.

Front view of H420.




Harmony top and control panel Three inputs, two for guitar or bass and one labeled accordian or mic. The guitar and bass input plus the accordian input are padded with a 470K resistor. The mic input has a 47K resistor. The 47K input is the same a the S6420 Thunderbolt.
Harmony rear view of amp 220629= Jensen. Made in 29th week of 1966 Closeup of speaker Model Number Capacitor and Power Tubes.

The schematic

Harmony 420. This schematic was redrawn from the version found at Schematic Heaven . That site has been up and down so much I decided to local host my own copy.

The similar amplifiers:



I have not been able to find any info on the amps listed above.

Based on what I can figure out, the Harmony 525 is electrically the same as this amplifier.


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