Four mixed make 12AT7 vacuum tubes tested as shown - Telefunken tested low - Mullard and others strong. 100% represents what you would expect from a NOS tube on our Amplitrex and 65% is considered too low to use. Please feel free to return items that do not meet your needs within the 30 day period, we only want satisfied customers! Thanks and God bless!
"But seek first the kingdom of God and his righteousness, and all these things will be added to you." Matthew 6:33