8
Tube Basics
The 12AX7 and 12AU7 tubes will have a life of about 5,000 to 10,000 hours. The lives of powertubes
are more difficult to predict. This also depends on how "gently" or "roughly" you use your amplifier. In
general -under normal conditions- you can say between 2,000 and 3,000 hours.
Here are some tips on using tubes:
• Do not use treatments on tube pins or in sockets.
• If you decide to experiment with other tube types, it's best not to swap tubes in and out repeatedly,
as you never want to cycle amplifiers on and off rapidly. They should be left off for at least five
minutes. Further, every time you insert a tube, you stand a chance of loosening the tube sockets.
It's okay to have fun, and we support that, but don't go crazy and swap tubes in and out twenty
times in a day.
• Do not leave the amplifier on 24 hours a day. Just a short warm-up is required for the PrimaLuna
to get into its groove.
• Break-in yields improvements. Every tube, when new, needs to be left alone for a little while. So,
when your amplifier is new, or when you re-tube it, it may take a little time to settle in. There is
however no fixed "time rule" for break-in.
• Please note that tubes can vary electrically, and by plugging in the wrong type of tube (i.e. 6922
for a 12AX7) you can damage the amplifier and void your warranty.
Common replacements:
•
12AX7
: ECC83, ECC803S, E83CC, 7025, CV4004. You can also use a 5751, but please note that
the 5751 is a lower gain tube than a 12AX7 and the sound will be altered.
•
12AU7
: ECC82, ECC802S, E82CC, 5814, 6189, CV4003
•
KT-88
: 6550, KT-90. You may also use EL-34, 6L6GC, 7581A and KT66 though power will drop
slightly.
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PrimaLuna
®
ProLogue Five