6SL7GT
6SL7GT has no equivalent designation confirmed by the archive. Completed sales put the typical price at $33.40 per tube.
The 6SL7-GT is a high-mu twin triode designed for use in resistance-coupled circuits as a voltage amplifier or phase inverter. It has a coated unipotential cathode and a T-9 glass envelope. The 12SL7-GT is identical to the 6SL7-GT except for heater ratings.
Construction
The 6SL7-GT and 12SL7-GT can be mounted in any position. They use a B8-6 intermediate-shell octal 8-pin base or a B8-46 short intermediate-shell octal 8-pin base, corresponding to RETMA 8BD and RETMA 9-11 or 9-41 base types. Pin assignments are: pin 1, grid of section 2; pin 2, plate of section 2; pin 3, cathode of section 2; pin 4, grid of section 1; pin 5, plate of section 1; pin 6, cathode of section 1; pins 7 and 8, heater.
Ratings
The 6SL7-GT heater is rated at 6.3 volts AC or DC at 0.3 amperes; the 12SL7-GT heater is rated at 12.6 volts AC or DC at 0.15 amperes. Maximum ratings for both types include a plate voltage of 300 volts, a positive DC grid voltage of 0 volts, a plate dissipation of 1.0 watt, and a heater-cathode voltage of 90 volts with the heater either positive or negative with respect to the cathode.
Characteristics
The datasheet specifies that gain is measured at 2.0 volts RMS output. It also gives maximum RMS voltage output for five percent total harmonic distortion as Eo.
Base OCTAL, viewed from below (the wiring side), pins numbered clockwise from the key. Read from the datasheet's basing table and checked against it automatically — confirm against the original datasheet before wiring.
| Measure | Per tube |
|---|---|
| Median | $33.40 |
| Typical range (25th–75th) | $18.75 – $59.90 |
| Most sales (10th–90th) | $11.24 – $99.99 |
| Extremes incl. outliers | $4.78 – $323.77 |
| Completed sales | 161 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| RCA | $25.86 | $14.99 – $44.33 | 47 |
| Sylvania | $34.99 | $24.95 – $51.45 | 37 |
| Tung-Sol | $66.00 | $49.99 – $97.44 | 25 |
| GE | $23.52 | $12.00 – $26.99 | 11 |
| National Union | $24.00 | $19.99 – $39.64 | 10 |
| Ken-Rad | $47.07 | $46.22 – $69.90 | 4 |
| Raytheon | $26.50 | $15.99 – $40.04 | 4 |
| Brimar | $100.00 | $74.29 – $323.77 | 3 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $38.75 | 72 |
| used | $25.00 | 59 |
Per-tube prices from completed sales, 2025-11-24 to 2026-09-26. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 6SL7GT, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| General Electric | 6SL7GT | PDF (359 KB) |
| RCA (HB3) | 6SL7GT | PDF (141 KB) |
| Tung-Sol | 6SL7GT | PDF (128 KB) |
| Brimar | 6SL7GT | PDF (95 KB) |
Documents held here and used to write this page.
- 6SL7-GT—12SL7-GT
1 further designation appears alongside 6SL7GT in the literature but below the evidence threshold used here, so it is not listed as equivalent.