Looking for guitar amplifier valves or tubes? See below current prices, suppliers and special offers for the KT77 Matched Pair Power Valves (2 x Tubes). Just click on the buy button on the right of the list and place your order. Matched guitar amplifier valves are used in most push pull valve amplifiers in the power output section. Matched, or balanced, valves are tested using the same conditions and then selected into sets with the same characteristics. This will ensure the valve guitar amp operates correctly, reliably and without noise and hum.
On the website your will find all the various guitar amp tubes your need to maintain and repair your valve guitar amp. From buying a single guitar amp tube, buying matched guitar amp valve sets for the power section and even complete guitar amplifier tube sets that include the full set of valves included in the amplifier.
Buy KT77 Matched Pair Power Valves (2 x Tubes) Below
Matched Amplifier Valves Explained
Why change the KT77 Matched Pair Power Valves (2 x Tubes) guitar amplifier valves within your guitar amplifier? Most Valve Combo Guitar Amplifiers, especially push-pull designs, require matched output tubes. In a push-pull guitar amplifier design one valve is pushing the speaker cone and one is pulling it. This may be a set of a matched pair of guitar amp valves (x 2), a matched quad of guitar amp valves (x 4) or a matched sextet of guitar amp valves (x 6). This will depend on the valve guitar amplifier circuit design and the output of the amplifier, the general rule being more valves more power.
Matched, or balanced, means someone has tested the valves under the same conditions and chosen the tubes with the same characteristics to make them into a set. As the sound generated by the speaker cabinet is reliant on a clean signal it is important that the valves push and pull in equal measure. Read our guitar amplifier technical pages on the design of a Push Pull valve guitar amplifier and also a Single Ended valve guitar amplifier to understand how the technology works.
You may be tempted to buy single guitar amp valves and insert them into the existing valve guitar amplifier circuit to get the amp working again however this may lead to more cost in the long run. First read the manufacturers instructions for the guitar amplifier to find out what they advise on buying and changing the valves. If the guitar amplifier needs matched valves buying a single valve and inserting it in the power stage could cause the amplifier to be unreliable and noisy. If unmatched valves are used in high power valve guitar amp it is highly likely that the output sound will be poor and most likely lead to expensive damage to other parts of the guitar amp circuit. Buying matched valves will ensure the valves have been individually tested for the same bias current under identical conditions of plate voltage and grid bias voltage.
When the valve amplifier is idle, eg not being played through, the matched valves will draw a small amount of bias current. If both valves are matched and drawing the same bias current, and have the same amount of gain, they will do a good job of cancelling any mains hum and other noise inside the guitar amplifier circuit. Also, it is likely that there will be a mismatch in the current draw, resulting in one valve getting hotter than the other valves in the amplifier. This may be severe enough to cause the valve to glow red which will reduce the life of the valve and overall reliability.
Buy Guitar Amplifier Matched Valve Sets
- 5881 Matched Pair Power Valves (2 x Tubes)
- 5881 Matched Quad Power Valves (4 x Tubes)
- 6550 Matched Pair Power Valves (2 x Tubes)
- 6550 Matched Quad Power Valves (4 x Tubes)
- 6550 Matched Sextet Power Valves (6 x Tubes)
- 6L6GC Matched Pair Power Valves (2 x Tubes)
- 6L6GC Matched Quad Power Valves (4 x Tubes)
- 6V6 Matched Pair Power Valves (2 x Tubes)
- ECC83 12AX7 Matched Pair (x 2)
- ECC83 12AX7 Matched Quad (4 x Tubes)
- ECC83 12AX7 Matched Quintet (5 x Tubes)
- ECC83 12AX7 Matched Sextet (6 x Tubes)
- ECC83 12AX7 Matched Triplet (3 x Tubes)
- EL34 6CA7 Matched Pair Power Valves (2 x Tubes)
- EL34 6CA7 Matched Quad Power Valves (4 x Tubes)
- EL84 6BQ5 Matched Pair Power Valves (2 x Tubes)
- EL84 6BQ5 Matched Quad Power Valves (4 x Tubes)
- KT77 Matched Quad Power Valves (4 x Tubes)
Buy Single Guitar Amplifier Valves
- 12AT7 (ECC81) Guitar Amplifier Valve (Tube)
- 12AU7 (ECC82) Guitar Amplifier Valve (Tube)
- 12AX7 (ECC83) Guitar Amplifier Valve (Tube)
- 12BH7 Guitar Amplifier Valve (Tube)
- 5751 Guitar Pre-Amplifier Valve (Tube)
- 5AR4 (GZ34) Rectifier Valve for Guitar Amplifier
- 6550 Power Valve for Guitar Amplifier (Alt KT88)
- 6L6 Guitar Amplifier Power Valve (Alt 5881 / KT66)
- 6V6-GT Power Valve for Guitar Amplifier (Tube)
- EL34 Power Valve for Guitar Amplifier (Alt 6CA7)
- EL84 Power Valve for Guitar Amplifier (Alt 6BQ5)
Also Consider these Full Replacement Valve Sets
- Full Guitar Amplifier Valve Kits <– Use this link if you know the valves used in your guitar amplifier.
- Look Up Your Guitar Amplifier Re-Valve Kit (Use this link to look up the kit for your guitar amplifier)
Tips on Changing Amplifier Valves
Once you have changed the KT77 Matched Pair Power Valves (2 x Tubes) valves in your amplifier make a note of the date that you did the work. This can be done by adding a sticker on to the back of your valve guitar amplifier. This will make it easy for you to review how long they have been in the valve guitar amp and allow you to decide when is best to change them again in the future. Guitar amplifier valves, or Tubes, will operate under normal working conditions for around 1000 hours, after this they may start to degrade however this will be gradual and maybe not noticed at first. Distortion and hum, or noise, are typically associated with faulty valves. Read our Guitar Amplifier Technical Pages and our tips for Valve Guitar Amplifier Maintenance and Changing Guitar Amplifier Valves.