BHK Preamplifier - Hours on the tubes

Hi all -

I just found out from another member that the BHK preamp keeps track of the hours on the tubes.

How do I find this information on the preamp?

thanks in advance…

If you press the black button to the left of the display for 3 seconds, you enter the Set Up Menu. You then press the black button a few times until you get to the Tube Life page which will display total hours on the current set of tubes. You can reset the hour number to zero by holding in the black button while on this page.


Oh wow, thanks for that information… I’ve never even noticed that button next to the display, i always use the remote.

My preamp shows that I have 1,300 hours on my tubes… How many hours before they should be replaced?

If you have spared tubes give them a try, but at 1300 hours these tubes should not have fading issue. My PSAVNE and GL tubes usually sounded great until 2k to 2.5k hours. But I don’t listen to loud volume and my amps are Class D.

Being input tubes on a preamp, I would think that volume isn’t an issue.

So, in theory, couldn’t you determine the life of the tube more accurately on a preamp input than on an amplifier input?

Both BHK pre and M1200 have the tubes at input stage, and I usually replace both around 2500 hours. But with NOS Telefunken they sound even better at 2500 hours.

Small input tubes can easily last 10,000 hours.

While they may have aged in a fashion which is not appealing to you, I suspect something else. Is the issue rather than the tubes.

I don’t disagree that the tubes at input stage will last for a long time. In my system around 2500 hours the sound is fading a bit, and tube replacement will bring the magic back. The exception is with NOS Telefunken, even at 5000 hours the sound is still great.

I would replace the tubes in the preamp.
There should be magic in the system.
Replacing tubes should result in magic.
Just make sure the preamp has been off and unplugged for a while before messing with tube replacement.

Although I’m sure the small input tubes will “last” thousands of hours, some of the magic starts disappearing long before that. I usually replace the BHK pre and 250 tubes at around 1000 hrs, and the system sounds reinvigorated again.

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See, e.g., Tube Basics and Frequently Asked Questions – Upscale Audio

Of course, YMMV.