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Pantode and Tetrode What is the difference?

What is the difference between Pantode and Tetrode tube?
I have a Antique Sound Lab Hurricanes Mono Blocks and the instruction say I can use the KT88s or a Pantode can someone explain the difference and sound qualities each type will offer.
What are the pros and cons for each type.
Why would one chose one over the other.

Another question is tube matching what defines a matched tube.
New tubes are sold in a matched pair (The KT88s)

If you mix the tubes up how does one find the matched pair, is it not all down to biasing them on the amp, regardless of tube you use.

The later is because I recived the amp with 5 broken tubes and I now have to replace them but if 3 of the busted tubes are one of a matched pair will it impact the sound if I use a new tube, as that will not be matched.
Thanks
punkuk
herman
2,267 posts
 
If your amp allows you to bias each tube separately then being matched is not important as long as they are reasonably close. If your amp biases them as pairs or quads then they should be matched. If you mix them up you must have a tube tester to sort them out again.

In general as you add electrodes (triode (3) to pentode (5)) you get more gain but most will say a colder sound.

Most audio power tubes are either triodes or pentodes. By connecting some of the pentode pins together you can make it act like a triode.
marakanetz's avatar
marakanetz
5,473 posts
 
Tetrode has two grids and
Penthode has three grids

If all grids are shorted than the bulb works the same as triode. If not than each grid can be used as an extra gain stage to amplify the voltage.

If grids have different polarity but the same offset DC voltage, they create a unity gain buffer i.e negative feedback.
biomimetic
252 posts
 
KT88's often are described as clearer and more linear, pentodes like an EL34 or something, are often described as warmer or lusher. If you bought the amps new, you should have them replace the tubes. You shouldn't have to pay. If you don't have individual biasing for each socket, yes, check the manual. If it says in pairs then match. If not, don't bother.
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