Vacuum Tube - 12AX7LPS, Sovtek
9 pin miniature preamp tube (Amplification Factor = 100). This Russian tube is full bodied and well balanced. It has a high gain with a very smooth presentation. In overdrive, it is not quite as defined as the 12AX7-S-JJ, but it offers more crunchy fizz. For more information about our 12AX7 tubes, see our tech corner article on 12AX7s.
RoHS Compliant
| Amplification Factor | 94 | |
| Capacitance, Cathode to Heater | 5.0 nF | |
| Capacitance, Grid to Cathode | 1.6 pF | |
| Capacitance, Grid to Heater | 1.6 pF | |
| Capacitance, Plate to Cathode | 0.46 pF | |
| Capacitance, Plate to Heater | 0.46 pF | |
| Capacitance, Plate to Plate | 600 pF | |
| Capacitance, grid to plate | 1.7 pF | |
| Grid Circuit Resistance (Rg), Fixed Bias | 1 MΩ | |
| Grid Circuit Resistance (Rg), Self Bias | 2.2 MΩ | |
| Grid Reverse Current | 0.2 μA | |
| Heater Voltage | 6.0 - 6.6 V / 12.0 - 13.2 V | |
| Heater to Cathode Voltage | 200 V | |
| Plate Current (Ia) | 8 mA | |
| Plate Dissipation (Wa) | 1.2 W | |
| Plate Resistance (Ra) | 56 kΩ | |
| Plate Voltage (Ua) | 330 V | |
| Transconductance (S) | 1.7 mA/V |
| Packaging Dimensions | 1 in. × 1 in. × 3 in. | |
| Weight (Packaging) | 0.037 lbs. |
 Specification Sheet | All Models |
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Questions and Answers
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1 answers
How would these sound in my vox vt20x?
Asked by Anonymous on March 9th, 2017.
March 9th, 2017
Staff Member
These tubes have a balanced eq and are nice and smooth.
Substitute Products
The following items can be substituted for this product. While not necessarily exactly the same, they will function as replacement items in your project.
Product Reviews
THE phase inverter tube in my opinion. I stock them. I've used dozens, in new builds, upgrades and repairs. Also can provide a nice warm tone in the V1 spot in a head cab ONLY. Speaker/cabinet/chassis vibrations can harm this long-plate tube, according to some.
These are great and reliable tubes for phono sections of stereo preamps. They have very long life way over 6000 hours. The EH short plate version is quieter but not as warm sounding. Those will last a long time too. Highly recommend the Sovtek 12AX7LPS +++++
I can't attest to this tube's value in any place but the driver stage, but in that position there is no other tube I would even consider. The best.