You can select the "Matched Triode Sections" upgrade option for most common audio preamp tubes. This is the most accurate service available to insure that all your pre-amp tubes have equal gain.
The service fee for this upgrade is $5.00 cost per tube. When you order a tube with this upgrade the shopping cart will show this option below the tube price and a separate line will be added below showing the $5.00 service fee.
This is the most accurate service available to insure that all your pre-amp tubes have equal gain.
1. How do you order matched pairs or quartets? To order a matched pair of pre-amp tubes, you must have an order quantity of "2" in your shopping cart with "Matched Triodes" selected. The shopping cart will show this option below the tube price and a separate line will be added below showing the $5.00 service fee with a quantity of "2".
To order a quartet, your order quantity should be 4 with "Matched Triodes" selected. The shopping cart will show this option below the tube price and a separate line will be added below showing the $5.00 service fee with a quantity of "4".
If you order an odd number of tubes we will match them together as well (if you would like a pair and a spare, for example).
We reserve the right to limit the maximum quantity of identical tubes to 5. If you order more than this we can usually fulfill it however sometimes we can’t with the stock on hand and will group your order as best as possible. (Example – You order 10 and we will ship two sets of 5).
2. What does "Matched Sections" mean anyway? Many of the most commonly used pre-amp tubes (e.g. 12AX7, 12AU7, 12AT7, 6922) actually have two identical sections inside of them. These two sections are technically called triodes and are intended to have equal electrical performance characteristics. It is two tubes in one enclosure. When you pay extra for the "Matched Sections" tubes you are getting the assurance that every triode section in every tube will be as closely matched as possible, ensuring balance.
3. What do you get when you order "Matched Sections" tubes? Tubes are manufactured to be within certain tolerance ranges according to a specification but like all electrical devices there are variances from tube to tube and section to section. By using "Matched Sections" tubes the two triode sections inside every pre-amp tube will be identical to each other and also, each triode section will also match every other triode section in other tubes of the same type. You are guaranteed that every triode section of every tube will match the spec for its type.
It is possible to get "matched" pre-amp tubes that are not balanced, meaning two tubes may match each other but their own halves are not identical. Our "Matched Sections" service is superior to this and insures that all pre-amp tubes (of a type) that you have ordered will be perfectly interchangeable with each other.
4. Who should use "Matched Sections" pre-amp tubes? For guitar players: if your amp has a "phase splitter" (or "phase inverter") it is important to have matched triode sections in this tube location because of how the tube is used in the circuit. For example, Fender amps often have a 12AT7 that is used this way. For other parts of the pre-amp stage in guitar amps this service is not necessary.
For audiophiles: For the best pre-amp performance possible, use matched and balanced pre-amp tubes.
5. What is the difference between a "Matched Sections" tube and a regular tube? Unless the tube is defective it will be within tolerance and will work fine in most applications. Some brands are better than others. When you pay extra for the "Matched Sections" tubes you are getting the assurance that every triode section in every tube will be as closely matched as possible.
Every matched tube is labeled with the triode section measurement. If you just want a regular tube, choose "None". You will get a regular tube that has had no special selection done and the tube will not be labeled.
The cost for the "Matched Sections" upgrade is $5.00 per tube; you will see the tube price increase when you put it in your shopping cart if you have selected "Matched Sections".