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Perfect Pair System

The Perfect Pair™ power tube numbering system makes it easy to replace the power tubes in your amplifier. In fact, it is the most accurate way to re-tube an amp without biasing.

Why use Perfect Pair matched power tubes?

- Best sound possible. Accurate matching eliminates crossover distortion.
- Longest tube life. Mismatched tubes wear out more quickly.
- Easy maintenance. Perfect Pair tubes are matched so closely, they are truly plug and play.

Once you have your amp biased with a Perfect Pair set of power tubes, you can re-tube the amp by simply putting in a new set with the same number.

    When you order a pair of Perfect Pair power tubes, there will be a sticker on the base of each tube (or on the box) that indicates the Perfect Pair number. You can use this number when ordering in the future to have plug and play operation with your new power tubes.
    Please ask us if there's a question we haven't answered here.

1. What is a tube numbering system?

As discussed on our power tube matching page, many amplifiers benefit from using matched tubes. Many tube amplifiers also require a simple procedure called “biasing” (again, there’s more info available) when the power tubes are replaced. The purpose of the numbering system is to eliminate the bias step – you simply plug in new tubes with the same number rating and start playing. Obviously, this can only work if you already have numbered tubes in your amp. Once you have your amp biased to a Perfect Pair set of tubes, you only need to order a number that’s close to it and you won’t need to re-bias your amp.

2. How does the Perfect Pair system compare to the classification systems used by Groove Tubes and Fender?

Most other numbering (or in Fender’s case, color coding) systems have a wide range of tube performance in each class. This means that when you buy a set of Fender “Red” tubes, the next time you buy them they may not be very closely matched to the last set. This isn’t generally a bad thing to do with fixed bias amps, but if your amp requires matched tubes it will definitely not sound it’s best. Our Perfect Pair system is the most accurate because we use the actual measurement of the tube’s plate current for the numbering system. So instead of ordering a Groove Tube “5” set that may include a wide range of tube measurements, you can order the exact same measurement as last time.

3. Why aren’t all numbering systems like this?

Since it is clearly the best way to sell matched tubes, all numbering systems should be this accurate. The real difficulty for any tube numbering system is in the retailing – you can’t get retailers to stock thirty different EL34’s for each brand! They compromised on amplifier tone where we don’t have to. Now you can get the most accurately matched tubes at the best price, because we retail them ourselves.

4. How do I order Perfect Pair tubes?

Although we sell many different types of matched power tubes, only the most common audio types have the Perfect Pair label. They include the most common audio power tubes: EL34 tube types, 6L6 tube types, 6V6 tube types, 6550 tube types, KT88 tube types, and EL84 tube types. To learn more about ordering matched pairs and quads see our Power Tube FAQ. If you are replacing Perfect Pair tubes, specify the Perfect Pair number that you would like to receive in the “Order Comments” box when you checkout and we will select accordingly.