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Discussion Starter #1
more specificity, it’s written on the amplifier that it uses EL34 or 6L6’s and I have 6L6’s on hand and it appears that 2 of the 8 pins have been pulled out of all 4 tubes. What is the purpose of this and are these tubes any good with the pins missing?
 

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Discussion Starter #4
I am working on my XXX but I took the back off my 6505 and these tubes also have one pin pulled. What is the purpose of this? Tomorrow I’ll look into getting a multimeter to adjust the Amp bias.
 

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I am working on my XXX but I took the back off my 6505 and these tubes also have one pin pulled. What is the purpose of this? Tomorrow I’ll look into getting a multimeter to adjust the Amp bias.
It's just so they comply with a standard tube base pattern. Back in the day there would have been 20 different tubes that used the same socket, with different pinouts.
 

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The 6L6 tubes often have those pins missing. It is more or less a safety thing from back in the day. It allows the use of the empty pins to be used as tie points for wiring. Sometimes you will even see the socket itself is missing those connections. You will also find KT88 tubes missing those pins as well. If you look at your XXX pins 1 and 8 are connected together at the socket. Since that amp can use EL34 or 6L6GC that connection has to be there. The EL34 does not have an internal connection, the 6L6 does. Download a data sheet for these tubes and look at the base wiring. Follow the connections to the pins, and you'll see what I mean.

In other words, if the tubes are known good. Don't worry about it.
 

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Discussion Starter #7
There are so many types of vacuum tubes. What all is compatible with my XXX besides EL34 and 6L6’s? I’m looking for a good metal tone and from what I come to understand any tube will work as long as it fits into place. The fellow I buy my HIFI equipment tells me otherwise.

What about 6V6, EL84, KT88, 5Y3? Is there any tube’s in particular that produce a versatile metal tone?
 

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I come to understand any tube will work as long as it fits into place.
Absolutely NOT.
Different tubes have different purposes, ratings, and pin configurations. Just randomly putting an 8 pin tube into an 8 pin socket is a recipe for disaster. At the very least it won't work, at worst major destruction, fire burnt out amp etc.
Stick with what the manufacturer says you can use.
What about 6V6, EL84, KT88, 5Y3?
Four completely different tubes.
EL84 isn't even an octal, 5Y3 is a rectifier, and putting a 6V6 where a 6L6 should go will probably result in a meltdown of the 6V6 very quickly depending on the amp. The KT88 may work, but depending on the available current from the power transformer may result in a blown transformer.

You need to do more research beyond the scope of this post before you start to randomly substitute tubes.
 
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