Vacuum Tube - 5881 / 6L6WGC, Sovtek
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Starting at: $20.65
Product Options
- Apex Matched Quad (T-5881-SOVT-MQ)
The 5881 is a very reliable tube that is widely used in many current production tube amplifiers. It has a warm tone with good 'bite.' This modern version is able to tolerate higher voltages than its 5881 / 6L6 cousins. The Sovtek 5881 delivers a warm, round tone that "sweetens" any vintage or modern guitar amp design. Built to rigid military standards, the 5881 will tolerate higher voltages than any other 6L6. In fact, they're frequently used as replacements for the old 7027 model in vintage Ampegs. Extremely consistent from piece to piece. The Sovtek 5881 has a heater voltage of 6.3 volts at 0.88 amperes. Maximum plate voltage is 250 volts while maximum plate current is 73 mA. The 5881 has a Transconductance rating of 6000 micromhos and a maximum output power of 5.8 watts.
Matched versions of this tube use Apex Matching
RoHS Compliant
| Single or Matched | Our Part Number | UPC/EAN |
|---|---|---|
| Apex Matched Pair | T-5881-SOVT-MP | 609722124010 |
| Apex Matched Quad | T-5881-SOVT-MQ | 609722124027 |
| Single | T-5881-SOVT | 683274021294 |
| Capacitance, Cathode to Heater | 11 pF | |
| Capacitance, Transfer | 1.0 pF | |
| Capacitance, input | 11 pF | |
| Capacitance, output | 6.7 pF | |
| Cathode to Heater Insulation Resistance | 4 MΩ | |
| Filament Current (If) | 840 - 920 mA | |
| Grid 1 Insulation Resistance | 200 MΩ | |
| Grid 1 Inverse Current | 0.5 mA | |
| Grid 2 Current | 6 mA | |
| Height, base to top | 3.25 in. | |
| Internal Resistance (Ri) | 18 kΩ - 75 kΩ | |
| Non-linear Harmonic Distortion | 15 % | |
| Output Power (POut) | 5.8 W | |
| Plate Current (Ia) | 60 mA - 86 mA | |
| Readiness Time | 50 s | |
| Transconductance (S) | 5.2 mA/V - 6.8 mA/V |
| Packaging Dimensions | Apex Matched Pair version | T-5881-SOVT-MP | 5.1 in. × 3.5 in. × 1.8 in. |
| Apex Matched Quad version | T-5881-SOVT-MQ | 5.1 in. × 3.5 in. × 3.5 in. | |
| Single version | T-5881-SOVT | 1.5 in. × 1.5 in. × 4 in. | |
| Weight (Packaging) | Apex Matched Pair version | T-5881-SOVT-MP | 0.294 lbs. |
| Apex Matched Quad version | T-5881-SOVT-MQ | 0.588 lbs. | |
| Single version | T-5881-SOVT | 0.147 lbs. |
| T-5881-SOVT-MP - Apex Matched Pair version | Capacitance, Cathode to Heater | 11 pF |
| Capacitance, Transfer | 1.0 pF | |
| Capacitance, input | 11 pF | |
| Capacitance, output | 6.7 pF | |
| Cathode to Heater Insulation Resistance | 4 MΩ | |
| Filament Current (If) | 840 - 920 mA | |
| Grid 1 Insulation Resistance | 200 MΩ | |
| Grid 1 Inverse Current | 0.5 mA | |
| Grid 2 Current | 6 mA | |
| Height, base to top | 3.25 in. | |
| Internal Resistance (Ri) | 18 kΩ - 75 kΩ | |
| Non-linear Harmonic Distortion | 15 % | |
| Output Power (POut) | 5.8 W | |
| Plate Current (Ia) | 60 mA - 86 mA | |
| Readiness Time | 50 s | |
| Transconductance (S) | 5.2 mA/V - 6.8 mA/V | |
| T-5881-SOVT-MQ - Apex Matched Quad version | Capacitance, Cathode to Heater | 11 pF |
| Capacitance, Transfer | 1.0 pF | |
| Capacitance, input | 11 pF | |
| Capacitance, output | 6.7 pF | |
| Cathode to Heater Insulation Resistance | 4 MΩ | |
| Filament Current (If) | 840 - 920 mA | |
| Grid 1 Insulation Resistance | 200 MΩ | |
| Grid 1 Inverse Current | 0.5 mA | |
| Grid 2 Current | 6 mA | |
| Height, base to top | 3.25 in. | |
| Internal Resistance (Ri) | 18 kΩ - 75 kΩ | |
| Non-linear Harmonic Distortion | 15 % | |
| Output Power (POut) | 5.8 W | |
| Plate Current (Ia) | 60 mA - 86 mA | |
| Readiness Time | 50 s | |
| Transconductance (S) | 5.2 mA/V - 6.8 mA/V | |
| T-5881-SOVT - Single version | Capacitance, Cathode to Heater | 11 pF |
| Capacitance, Transfer | 1.0 pF | |
| Capacitance, input | 11 pF | |
| Capacitance, output | 6.7 pF | |
| Cathode to Heater Insulation Resistance | 4 MΩ | |
| Filament Current (If) | 840 - 920 mA | |
| Grid 1 Insulation Resistance | 200 MΩ | |
| Grid 1 Inverse Current | 0.5 mA | |
| Grid 2 Current | 6 mA | |
| Height, base to top | 3.25 in. | |
| Internal Resistance (Ri) | 18 kΩ - 75 kΩ | |
| Non-linear Harmonic Distortion | 15 % | |
| Output Power (POut) | 5.8 W | |
| Plate Current (Ia) | 60 mA - 86 mA | |
| Readiness Time | 50 s | |
| Transconductance (S) | 5.2 mA/V - 6.8 mA/V |
 Specification Sheet | All Models |
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Questions and Answers
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1 answers
Hello which is the Max Dissipation Watt for this tube?
Asked by Anonymous on November 19th, 2015.
November 19th, 2015
Staff MemberTop Contributor
The Max Dissipation is 23.5 watts.
1 answers
Good for a line 6 spider valve mk11 hd100?
Asked by Anonymous on February 23rd, 2018.
February 28th, 2018
Staff Member
From the Line 6 Spider Valve mkii HD100 manual, your amp takes a pair of 5881's and these should work.
1 answers
Need set of 6 tubes for 1978 Fender Super twin amp. Single or matched? What’s the difference?
Asked by Anonymous on March 10th, 2020.
March 11th, 2020
Staff Member
Power tubes are electrically matched so each tube will have the same amount of “idle” plate current and amplification characteristics when used in an amplifier. This is done so the tubes can work together in your amp giving you optimal sound quality and tube longevity. Matched tubes also receive extra quality checks to reduce the possibility of getting a faulty power tube that may have slipped by the manufacturer.
1 answers
Will I have to re-bias my ‘66 Fender Super Reverb if I install these sovtec 6l6WGC power tubes. I am handy with most repairs, but not at the level of a qualified amp tech. Also the same with changing out the rectifier tube (5U4GB) ?
Asked by Anonymous on October 28th, 2020.
October 28th, 2020
Staff Member
We aren't able to say whether or not your amp will need to be rebiased when getting a new set because that would require us to have access to detailed info on the ratings of the original tubes. It is safe to assume that your amp would need a bias adjustment when changing power tubes. Rectifier tubes do not carry the same requirement.
Substitute Products
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Product Reviews
I bought matching quartet to replace my older Sovtek 5881`s...almost one full year one of these failed.Went full purple with HUGE hum from speakers.I removed the tubes and put the old pones back in...way better.They do not make tubes worth a crap anymore.I had exact same issue with RUBY...brand new,one failed in about 2 months.So far the MULLARD EL34`s are holding up.
These Sovtek 5881 tubes are perfect for my 1966 Supro Thunderbolt. This amp runs the tubes hot and they just seem to like it that way. Nice crunch when pushed hard.
These things sound RAD! Tight, nice compression.
Very pleased with the "sound" of these Sovteks. Smooth midrange and high end with solid bass. I like these better than some of the more expensive 6L6's
Good basic power tubes