Listing Title:
Vintage 1958 RCA 12AX7 / ECC83 Red Tip Long Grey Plate – Matched Triodes (121/120) V1 Tested
Category:
Vacuum Tubes / Amp Parts
Condition:
Very Good (Used)
Description
Up for sale is a rare vintage 1958 RCA 12AX7 / ECC83 dual triode vacuum tube featuring original 17mm Long Dark Grey Plates and a Factory Red Tip (Low-Noise / Special Selection Marking).
Red-tipped vintage American tubes were specially selected at production for critical low-noise, low-microphonic applications. Paired with its virtually spot-on 1% triode match, this is an absolute top-tier candidate for a high-end Phase Inverter (V5), stereo hi-fi preamp, or ultra-quiet V1 input slot.
KEY FEATURE: Factory Red Tip Marking
Red Tip Designation: Indicates factory/OEM hand-screening for ultra-low noise floor and high-stability performance.
Dual-Stage Testing & Verification
This tube has undergone complete screening on the bench and under real-world high voltage:
Bench Screening (EICO 666 Tester):
Triode 1 Score: 121 (Strong Emission)
Triode 2 Score: 120 (Strong Emission)
Triode Balance: ~1% Match (Ideal for Phase Inverter or Stereo Hi-Fi balance)
Shorts / Leaks: PASSED (Zero heater-cathode shorts or internal leaks).
Gas Test: PASSED (Clean, stable operation).
High-Voltage Amp Audition (PRS Archon @ 400V+ DC):
V1 Input Slot Tested: Auditioned in the high-gain V1 position of a PRS Archon under full operating voltage.
Microphonics: PASSED. Tested via pencil/chopstick tap test under high gain—zero mechanical feedback, ringing, or microphonics.
Noise Floor & Tone: Exceptionally quiet noise floor. Delivers classic 1950s RCA 3D depth, sweet non-fatiguing top-end, and lush midrange bloom.
Details:
Brand: RCA (Radio Corporation of America)
Tube Type: 12AX7 / ECC83 / 7025
Special Marking: Factory Red Tip (Low-Noise / Premium Selected Grade)
Plate Construction: 17mm Long Dark Grey Plates
Year of Manufacture: Circa 1958
Origin: Made in USA
Ships securely packed in a sturdy box with generous bubble wrap via USPS Ground Advantage with tracking. Buy with confidence
| Listed | 5 days ago |
|---|---|
| Condition | Very Good (Used) Very Good items may show a few slight marks or scratches but are fully functional and in overall great shape.Learn more |
| Brand | |
| Model |
|
| Finish |
|
| Categories | |
| Year |
|
Product safety information may be available here.




