5V4G GZ32 SILVERTONE by Sylvania ST Shape Black Plates Bottom Square Getter Tested Tube Made in USA '51
Description:
The Silvertone-branded 5V4G/GZ32 , produced in 1951 by Sylvania for the audio line of Sears, Roebuck & Co. , features the classic ST bottle structure, well-machined vertical black plates and square getter at the bottom . It is one of the most musical and transparent versions of the first post-war generation American rectifiers.
Prized for its combination of electrical robustness , tonal refinement and natural current decay , this valve is particularly suited to high-sensitivity systems , high-end hi-fi restorations or driver stages where the quality of the rectification is directly reflected in the dynamic response and articulation of the audio signal.
Bass : elegant and natural. The low range is distinguished by roundness and coherence , with a response that favors harmony rather than impact. There is no compression or swelling, but an “analog” presence that enriches the musical base with warmth and depth.
Mids : velvety and musical. The mid frequencies are the strong point of this 5V4G, with a soft, fluid and refined performance. The voices are warm and present , with an emotional texture that recalls the sound of 50s hi-fi systems, but without loss of definition.
Highs : soft and airy. The high range extends delicately and without grain , offering a discreet brilliance and a feeling of airiness that accompanies listening without tiring. Excellent rendering of secondary details, particularly in reverberations and natural harmonics.
Dynamics : progressive and not aggressive. The transient response is gradual and controlled , with an expressive and natural microdynamics. The behavior is musical , closer to a European GZ32 than to an aggressive American rectifier.
Soundstage : extended and deep. The soundstage opens with fluidity and coherence , offering an orderly three-dimensional image, with excellent separation of the planes and realistic presence of the recording environments .
🎧 Use in Headphone Amplifiers and Driver Stages Hi-Fi
An excellent choice for low-current tube power supplies, high-end preamps or tube DACs, where tonal finesse and low noise are essential. Ideal with reference headphones that value signal delicacy , such as the ZMF Verité , Audeze LCD-4 or Audio-Technica ADX5000 .
🎸 Use in Guitar and Bass Amplifiers
Less common in guitar, but perfect in low-power amps or vintage studio circuits , where you want a smooth sag , natural compression and a sweet attack. Great for jazz, fingerstyle, nuanced cleans and organic vintage tones.
🎯 Note for audiophiles and technicians
A refined rectifier with a romantic soul , which combines the aesthetic charm of the ST shape with the sweet and musical voice typical of vintage Sylvania production. Ideal for author restorations, low-power systems and lovers of transparency without harshness .
Test Results
Tubes Tested on Funke W19 Tube Tester:
Voltage Test: Va = 60V, Vf = 5V
Good from: Ia = 55 mA
Average 100%: Ia = 84.6 mA
TEST RESULT: VERY STRONG
Valve :
- Section 1 : Ia = 70 mA
- Section 2 : Ia = 70 mA
Additional Tests Performed:
- Output Quality: Excellent – Very strong and stable output, no fluctuations.
- Short circuits and GAS: Absent.
Conditions:
- Condition: Vintage Tubes - Tested and in perfect working order. Supplied in our custom box for optimum protection.
- Functionality: Fully functional.
- Cosmetic Condition: Good – Lettering partially eroded, but still legible. Valve body in good condition. See photos for details.
- Manufacturing Code: 312 152 - Manufacturing SYLVANIA USA. 52nd week of 1951.
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