1) A pair of NEC 12AD7 vacuum tubes. The 12AD7 is a low noise, low hum variant of the 12AX7 and is a drop in replacement. These tubes, made by NEC Japan, have angeled halo getters. They also have matching "4Z" codes and have been tested on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 91% Triode 2: 91%
Tube 2: Triode 1: 92% Triode 2: 92%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of both tubes performed excellently.
I would like $60 plus shipping for these tubes.
2) A trio of 6679 12AT7 tubes manufactured by RCA. The 6679 tube was originally manufactured for mobile communication and maintain output even with variations of filament voltage. They are equivalent to a 12AT7 tubes. These tubes have square getters and all three have the date code of "6122" which equates to the 22nd week of 1961. These tubes have been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 102% Triode 2: 103%
Tube 2: Triode 1: 102% Triode 2: 102%
Tube 3: Triode 1: 102% Triode 2: 102%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of all three tubes performed excellently.
I would like $50 plus shipping for these tubes.
3) A pair of General Electric 12AY7 tubes. These tubes have angled square getters and grey plates. They have been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 95% Triode 2: 94%
Tube 2: Triode 1: 95% Triode 2: 95%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of both tubes performed excellently.
I would like $40 plus shipping for these tubes.
4) A Mullard ECC81 12AT7 vacuum tube. This tube has a square getter and has the code sequence Tk1 B8F with the "B" signifying the Blackburn, England Mullard plant where this tube was produced. This tube has been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 100% Triode 2: 99%
In addition this tube has had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of the tube performed excellently.
I would like $25 plus shipping for this tube.
5) A pair of RCA 12BH7 tubes. These tubes have long, grey plates and halo getters. They have been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 94% Triode 2: 93%
Tube 2: Triode 1: 97% Triode 2: 97%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. The second tube showed a slight reduction in emission but this was not excessive.
I would like $20 plus shipping for these tubes.
6) An RCA 6201 12AT7 tube. This tube has triple mica construction as well as black plates. It has been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 102% Triode 2: 102%
In addition this tube has had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of the tube performed excellently.
I would like $20 plus shipping for this tube.
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 91% Triode 2: 91%
Tube 2: Triode 1: 92% Triode 2: 92%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of both tubes performed excellently.
I would like $60 plus shipping for these tubes.
2) A trio of 6679 12AT7 tubes manufactured by RCA. The 6679 tube was originally manufactured for mobile communication and maintain output even with variations of filament voltage. They are equivalent to a 12AT7 tubes. These tubes have square getters and all three have the date code of "6122" which equates to the 22nd week of 1961. These tubes have been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 102% Triode 2: 103%
Tube 2: Triode 1: 102% Triode 2: 102%
Tube 3: Triode 1: 102% Triode 2: 102%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of all three tubes performed excellently.
I would like $50 plus shipping for these tubes.
3) A pair of General Electric 12AY7 tubes. These tubes have angled square getters and grey plates. They have been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 95% Triode 2: 94%
Tube 2: Triode 1: 95% Triode 2: 95%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of both tubes performed excellently.
I would like $40 plus shipping for these tubes.
4) A Mullard ECC81 12AT7 vacuum tube. This tube has a square getter and has the code sequence Tk1 B8F with the "B" signifying the Blackburn, England Mullard plant where this tube was produced. This tube has been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 100% Triode 2: 99%
In addition this tube has had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of the tube performed excellently.
I would like $25 plus shipping for this tube.
5) A pair of RCA 12BH7 tubes. These tubes have long, grey plates and halo getters. They have been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 94% Triode 2: 93%
Tube 2: Triode 1: 97% Triode 2: 97%
In addition these tubes have had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. The second tube showed a slight reduction in emission but this was not excessive.
I would like $20 plus shipping for these tubes.
6) An RCA 6201 12AT7 tube. This tube has triple mica construction as well as black plates. It has been tested for shorts, grid leakage and emission on a restored and calibrated Sencore TC-142. The results are as follows:
Shorts: PASS
Grid Leakage: PASS
Emission:
Tube 1: Triode 1: 102% Triode 2: 102%
In addition this tube has had a life test performed on it which entails reducing the filament voltage of the tube under test by one step and noting any significant reduction in emission performance. Both triodes of the tube performed excellently.
I would like $20 plus shipping for this tube.
