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Vacuum Tube - KT77, JJ Electronics
The JJ Electronic KT77 is a reproduction of the original tubes that captures the sound that made the KT77 famous. In their typical fashion, JJ has built this tube in a solid construction that is robust and highly reliable. This tube has more headroom than a typical EL34. The low end is fat and defines with detailed and responsive mids and smooth highs. This is an excellent tube for adding more power to the sound of an EL34 amp.
Matched versions of this tube use Apex Matching
RoHS Compliant
Accessory Items:
| Single or Matched | Our Part Number | UPC/EAN | JJ Electronics Part Number |
|---|---|---|---|
| Apex Matched Pair | T-KT77-JJ-MP | 609722123167 | |
| Apex Matched Quad | T-KT77-JJ-MQ | 609722123174 | |
| Single | T-KT77-JJ | 609722123150 | KT77 |
| Body Height | 98 mm | ||
| Cathode Current (Ik) | ≤ 180 mA | ||
| Filament Current (If) | 1.4 A | ||
| Filament Voltage (Uf) | 6.3 V | ||
| Gain (μ) | 11.5 | ||
| Grid 1 voltage (Ug1) | -13.5 V typical | ||
| Grid 2 current (Ig2) | ≤ 10 mA | ||
| Grid 2 dissipation (Wg2) | 6 W | ||
| Grid 2 voltage (Ug2) | ≤ 600 V, 250 V typical | ||
| Grid capacitance (cg1) | 16.5 pF | ||
| Grid to Plate Capacitance (ca/g) | 1 pF | ||
| Internal Resistance (Ri) | 23 kΩ | ||
| Item Diameter | 33.3 mm | ||
| Item Height | 112 mm | ||
| Plate Capacitance (ca) | 9 pF | ||
| Plate Current (Ia) | 100 mA | ||
| Plate Dissipation (Wa) | ≤ 25 W | ||
| Plate Voltage (Ua) | ≤ 800 V, 250 V typical | ||
| Transconductance (S) | 10.5 mA/V | ||
| Packaging Dimensions | Apex Matched Pair version | T-KT77-JJ-MP | 4.8 in. × 3.3 in. × 1.6 in. |
| Apex Matched Quad version | T-KT77-JJ-MQ | 4.8 in. × 3.3 in. × 3.3 in. | |
| Single version | T-KT77-JJ | 1.6 in. × 1.6 in. × 4.6 in. | |
| Weight (Packaging) | Apex Matched Pair version | T-KT77-JJ-MP | 0.269 lbs. |
| Apex Matched Quad version | T-KT77-JJ-MQ | 0.538 lbs. | |
| Single version | T-KT77-JJ | 0.1345 lbs. |
| T-KT77-JJ-MP - Apex Matched Pair version | Body Height | 98 mm |
| Cathode Current (Ik) | ≤ 180 mA | |
| Filament Current (If) | 1.4 A | |
| Filament Voltage (Uf) | 6.3 V | |
| Gain (μ) | 11.5 | |
| Grid 1 voltage (Ug1) | -13.5 V typical | |
| Grid 2 current (Ig2) | ≤ 10 mA | |
| Grid 2 dissipation (Wg2) | 6 W | |
| Grid 2 voltage (Ug2) | ≤ 600 V, 250 V typical | |
| Grid capacitance (cg1) | 16.5 pF | |
| Grid to Plate Capacitance (ca/g) | 1 pF | |
| Internal Resistance (Ri) | 23 kΩ | |
| Item Diameter | 33.3 mm | |
| Item Height | 112 mm | |
| Plate Capacitance (ca) | 9 pF | |
| Plate Current (Ia) | 100 mA | |
| Plate Dissipation (Wa) | ≤ 25 W | |
| Plate Voltage (Ua) | ≤ 800 V, 250 V typical | |
| Transconductance (S) | 10.5 mA/V | |
| T-KT77-JJ-MQ - Apex Matched Quad version | Body Height | 98 mm |
| Cathode Current (Ik) | ≤ 180 mA | |
| Filament Current (If) | 1.4 A | |
| Filament Voltage (Uf) | 6.3 V | |
| Gain (μ) | 11.5 | |
| Grid 1 voltage (Ug1) | -13.5 V typical | |
| Grid 2 current (Ig2) | ≤ 10 mA | |
| Grid 2 dissipation (Wg2) | 6 W | |
| Grid 2 voltage (Ug2) | ≤ 600 V, 250 V typical | |
| Grid capacitance (cg1) | 16.5 pF | |
| Grid to Plate Capacitance (ca/g) | 1 pF | |
| Internal Resistance (Ri) | 23 kΩ | |
| Item Diameter | 33.3 mm | |
| Item Height | 112 mm | |
| Plate Capacitance (ca) | 9 pF | |
| Plate Current (Ia) | 100 mA | |
| Plate Dissipation (Wa) | ≤ 25 W | |
| Plate Voltage (Ua) | ≤ 800 V, 250 V typical | |
| Transconductance (S) | 10.5 mA/V | |
| T-KT77-JJ - Single version | Body Height | 98 mm |
| Cathode Current (Ik) | ≤ 180 mA | |
| Filament Current (If) | 1.4 A | |
| Filament Voltage (Uf) | 6.3 V | |
| Gain (μ) | 11.5 | |
| Grid 1 voltage (Ug1) | -13.5 V typical | |
| Grid 2 current (Ig2) | ≤ 10 mA | |
| Grid 2 dissipation (Wg2) | 6 W | |
| Grid 2 voltage (Ug2) | ≤ 600 V, 250 V typical | |
| Grid capacitance (cg1) | 16.5 pF | |
| Grid to Plate Capacitance (ca/g) | 1 pF | |
| Internal Resistance (Ri) | 23 kΩ | |
| Item Diameter | 33.3 mm | |
| Item Height | 112 mm | |
| Plate Capacitance (ca) | 9 pF | |
| Plate Current (Ia) | 100 mA | |
| Plate Dissipation (Wa) | ≤ 25 W | |
| Plate Voltage (Ua) | ≤ 800 V, 250 V typical | |
| Transconductance (S) | 10.5 mA/V |
 Specification Sheet | All Models |
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Questions? Contact us at [email protected], or give us a call at 480-296-0890
Product Reviews
Big, full-bodied tone; like an EL34, but with more headroom and full, tight bottom end. The highs are punchy but not piercing. I put them in my Diezel Paul 45 watt head...they're stock in many Diezel amps, and it's a great fit. I'll have to try them in my Marshalls one of these days.
Great Tubes ! These are some of the best sounding tubes I have gotten so far..
I will be buying these again...
A+ service and product again. Thanks guys! Lifetime customer. I cant fimd a better tube than the kt77s from amplified parts. Ive been through ever different tube under the sun, and always end up with jjkt77s in all my amps. Tone heaven after burned in and bias correctly.
Put a quad of these KT77s in my Marshall JVM 410H. Also got two Tung Sol and three JJ 12ax7s. Sounds very mean...love them and hope these last for awhile.
High quality tubes, very quick shipping, well packed and great honest prices. Many thanks.