Supro Schematics - Tube amp Schematics 38 rowsClick the link above for Tube amp info, Schematics, Board building information, Projects, Mods, Transformer diagrams, Photo's, Sound clips. There are hundreds of pages of Tube amp information on my library page.#SUPRO SCHEMATICS - FILE SIZE10_see_valco_section_also - 1 Kb2Supro_1624t_schematic_263 - 57 Kb3Supro_1690t - 262 Kb4Supro_1946 - 52 KbSee all 38 rows on el34world 1624T Dual-Tone – Supro 1624T Dual-Tone. The “Dual-Tone” 1 x 12 combo amplifier is the undeniable rock star of the mid 60’s Supro amplifier lineup. Vintage 1624T amps have been sought-after for decades because they embody the most desirable aspects of the Supro sound. As the Dual-Tone’s volume knob is turned beyond noon, a fat and compressed clean tone evolves..