Decware Zen Triode Preamp Owner's Manual page 10

O W N E R S M A N U A L
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TUBE HEATER CURRENT
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The three tubes of each channel have the heaters wired in series which means that ideally you want all three tubes
to match. It definitely means that where the factory tube compliment of 6N1P-EB tubs are concerned, you either
have to run all 6N1P-EB's or NONE at all. In other words, you can run 6922's, good strong 6DJ8's, or 7DJ8's. Some
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Russian 6N23P's may also work well so long as they are relatively matched.
To be clear, you can NOT mix 6N1P's with 6DJ8 or 6922 or 7DJ8 or any other compatible tube at the same time
without side effects. The reason for this is that the 6N1P has a higher current draw on it's heaters than all of the other
tubes mentioned. Running tubes with miss-matched current draws like this can have effects like having your 6N1P
prematurely fail, or having one or both of the other tubes run with starved heaters causing higher harmonic distortion
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which some people would actually like.
Also, when it comes time to change tubes if you notice one tube that has grown darker in appearance than the
others it is an indication that it was a weaker tube or had a heater that drew more current causing it to run hotter or
both. This is not a real sonic issue, but deserves explanation in so much that if you want all your tubes to balance
out perfectly and last the same amount of time aka wear evenly, then make sure they all match. Match the sections
of each tube and then match the tubes themselves. This will have little sonic benefit except over time, in that you'll
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get longer periods of time between tube changes.
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The factory tube compliment of 6N1P-EB tubes have a rated life of 6000 hours.
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TUBE HEAT IN GENERAL
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Due to the design of the ZTPRE's tube layout, even if configured without a selector and completely covered by a
metal plate (worse case scenario) there would still be adequate ventilation for the tubes out the back so no worries
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about overheating.
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WARM UP
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The ZTPRE has no unique requirements other than the typical warm up time associated with tube gear. After the
unit is turned on, the tubes will begin to warm up and glow and begin to pass signal after apron 30 seconds or so.
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The best sound quality, as with all tube gear, will come some time after the 20 minute mark.
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MAXIMUM ON TIME
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There is no time limit or suggested maximum amount of time the ZTPRE can be left on. If left on indefinitely it will
have to be turned off for tube replacement every 6000 hours.
Decware High Fidelity Engineering Co., East Peoria IL, USA www.decware.com