For Sale: Tested and working classic "420" guitar and bass amplifier. Made in or around 1965 in the USA.
Works 100%, great tone, no issues. Can get pretty loud. Info on the web indicates this was made by Valco for Harmony and "it's Harmonys version of the Supro Thunderbolt".
Appears to be all original and unmodified. Includes Jensen C15 PS 15" Special Design Musical Instrument speaker. Speaker made in 1965 and marked 220539, 550 15S C15 PS C7747-2. Has two 1/4" inputs marked Guitar or Bass and one 1/4" input marked Accordion or Microphone. Volume control, bass and treble controls, and a reversible polarity power switch. Red power indicator light is working. Shows some minor tarnish/wear to the chrome finish but no rust. Lettering is all intact. Minor wear to grill fabric and cabinet covering, not bad though.
Schematics can be found here: http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/bargainbin/harmony_h420.pdf
Some more general info found on the web:
...the Thunderbolt had a single volume and a single tone control while the Harmony H420 has volume, bass and treble controls. It is 100% original electrically. The tube line-up is 2 x 6L6GC and 2 x 12AX7. Hand wired point to point, it's unmistakably Valco, has not been messed with electrically and the big 15" Jensen is perfect and sounds wicked. The cabinet construction is finger jointed pine just like the Valcos with a plywood speaker baffle. The cabinet is finished in a very cool black ostrich tolex, a beautiful oxblood grill cloth, strong carry strap and four rubber feet. .... The H420 really sparkles with a Telecaster, has good bottom and breaks up sweet with a Les Paul, especially P90's. The cabinet dimensions are 24" H x 19" W x 10" D at the top and 11" D at the bottom. This amp sounds tremendous, it's plug and play. If you've been priced out of the Supro Thunderbolt market, don't miss out on this sonic sleeper. The amp weighs 36 lbs. unpacked.
Email for additional/higher resolution photos.
Send your zip code for ship cost - should be between $19.99 and $59.99 if you are in the continental USA (listed Feb. 2014).