SOLD - 45's - Sylvania - 1930's - Beautiful Matched Pair

YOU WILL RECEIVE THE EXACT PAIR PICTURED.  CHOOSE QTY 1 TO RECEIVE THIS EXACT PAIR.

TV-7 Test Results:

70/47

68/47

This is a mixed-brand pair with identical or extremely similar construction, strongly indicating the Super Silvertone is a Sylvania-manufactured rebrand.

This was common practice: Sylvania supplied tubes to retailers like Sears (Silvertone was Sears' house brand for radios, phonographs, and electronics), who applied their own labeling for in-house products or replacement sales. "Super" denoted premium/selected stock.

Key Identification and Construction Details

• Envelope: Both have the classic ST ("coke-bottle" or shoulder tube) glass shape — the standard mid-1930s form factor after earlier globe (rounded) UX-245 versions. Clear glass with domed tops.
• Base: Black molded Bakelite/plastic with 4 pins (UX4 base). The Sylvania has "SYLVANIA MADE IN U.S.A." etched in green, plus the "45" in a hexagon (a Sylvania signature for many 1930s–1940s tubes; hexagon often holds date/plant codes, though not fully visible here).
• Silvertone specifics: "Super Silvertone MADE IN U.S.A." in cursive script on the black base. This aligns with Sears' upscale branding; many Super Silvertone 45s are confirmed Sylvania-made (especially black-base ST versions with similar getters/plates).

• Internals (from bottom shots):
  • Hanging filament structure (visible wires/supports) — classic directly heated triode.
  • Plates: Appear dark/blackish or gray-black (likely carbonized black plates or coated gray-black), common in higher-quality mid-era 45s for better heat dissipation and reduced microphonics.
  • Getters: Bottom foil/D-getter (rectangular or D-shaped flashing at the base) — typical for Sylvania and rebrands in this period. Copious flashing suggests good vacuum integrity.
  • No major structural differences — internals match closely (same filament supports, mica spacers, plate shape), confirming same-factory origin.

Historical Context

Sylvania produced excellent 45s  — rugged, consistent, low noise. Sears sourced from top makers (RCA, Sylvania, etc.) for Silvertone products; "Super Silvertone" indicated higher-grade testing/cosmetics. These black-base ST examples fit mid-to-late 1930s production (post-globe era, pre-WWII shortages).

Performance and Sound Reputation

Vintage U.S.-made 45s like these are favorites for their "queen of tone" qualities:

• Rich, blooming midrange with exceptional vocal/instrument texture.
• Sweet, extended highs without glare.
• Controlled but not overly damped bass.
• Low distortion (mostly even-order harmonics) for natural "bloom" and 3D imaging in SET amps.

Sylvania versions (including rebrands) are often described as detailed, linear, and dynamic — slightly more "open" or neutral than warmer RCAs, with excellent microphonic control and low hum when filaments are balanced. Super Silvertone variants perform identically when Sylvania-made — some collectors note quiet/refined examples due to selection.

Comparisons:

• Vs. RCA 45: Sylvania/Silvertone often preferred for clarity/extension; RCA black-plate versions lusher/thicker.
• Vs. Tung-Sol or Ken-Rad: Similar ruggedness; Sylvania edges in refinement.
• Vs. globe UX-245: ST shapes like yours more reliable (less getter flaking), comparable/better sound in tested examples.
• Vs. modern 45s (JJ, Emission Labs, Takatsuki): Vintage U.S. superior for musicality/naturalness/low noise — though modern ones more reliable/higher output.

Overall, this is a nice, authentic 1930s U.S.-made pair — reliable Sylvania quality with historical charm. The similar construction despite labels makes them effectively a matched pair in practice.