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Would anyone like a tube hour counter for amps that don't have this function ?

I am planning and designing a small,  attractive,  external tube hour counter,  and I would like to get a sense if anyone is interested in this for themselves. If so I may be compelled to make a batch of these at the same time Rather than just one.

 I have an audio research VT100 mkII and and LS25. I really like these amplifiers, but neither of them have a way of tracking tube hours. I know I can just listen to the tubes to determine shortcomings, but I'm also an analytical sort of guy, so having an accurate tube hour count would be useful to me.

my plan is to use a digital, non-resettable, industrial hour counter.  I am planning to recess this into a small aluminum enclosure with professionally machined openings for the  Digital counter as well as the power cable coming out of the back. The plan is to use a  Black anodized aluminum body with natural aluminum face plate and rear plate. A power cable coming  out the back and be terminated to a standard household grounded plug. There will be rubber deer on the bottom. The device will be small: perhaps about 4 inches wide, 2 inches tall, and 4 inches deep.

 I have a six outlet power conditioner with one outlet free. To use this hour counter, I will plug it into my conditioner, I will switch off the power on the conditioner when I'm not using the amplifiers.  When I switch on the Power conditioner and subsequently the amplifiers, The hour counter  Will begin its count. 

 For those of you who plug their power amplifier directly into the wall, I suspect that many of you will still plug your preamplifier or other components into a conditioner or strip of some sort. In that case this tube hour counter will still work for you,  unless you just turn on your power amp from time to time for fun! 

 Since I will be re-tubing my power amp soon,  this is a perfect time for me to add this to my system.  I plan to use my small label making machine (brother p-touch style) to put a label on the bottom of the aluminum enclosure that has notes on the install date, tubes, and hour counter numbers. 

For example,  I may just change the power tubes on my amplifier and not touch the signal or driver tubes in the power amp, or the preamp tubes in the preamplifier at this time. When I go to change those smaller tubes in the future, I will notate that change and log the hour count in a  small note on the Label Maker,  and stick it to the bottom of the enclosure.  The hour counter will be non-resettable to avoid tampering or mistakes.

I'm not yet sure about the price of something like this, I'm doing the research now. Since it has to sit on my audio shelf, I don't want it to look like a piece of junk or a children's science project. Because of that, I will use professionally sourced parts, quality machining, and thoughtful design,  planning,  and careful assembly. 

 I suspect the final selling price may be in the neighborhood of $100 - $200. But that's just a wild guess at this point. If anyone's interested please let me know and I will consider  making several of these instead of just one for me! 

Take care,
Mark
marktomaras
folkfreak's avatar
folkfreak
1,349 posts
 
I've been following the discussion of tube hours with some interest and wanted to share a recent surprising experience I had. I have ARC gear which counts hours and on my Ref 2SE phono have a set of tubes with 430 hours on it, well within the 3,000 hour life. Recently however I began hearing breakup on one channel, sounded just like mistracking so I put it down to dirt on the stylus or issues with my setup. However when the same channel finally dropped 20dB and I isolated the issue to my phono amp I realized I must have a tube issue. Replacing the set of four 6H30s cleared up all the problems

i do use herbies dampers so it may be that the extra pressure reduces tube life, or maybe it's as much how many stop starts you have as it is total hours (I tend to have shorter listening sessions)

moral of the story is hours is only a rough guide, a good preventative maintenance policy of replacing every 5 years or so is probably not a bad idea and using aggressive dampers like the herbies may impact life
marktomaras OP
544 posts
 
FolkFreak,  I agree wholeheartedly!  However, in my case, and hence the idea for this project, I have absolutely no idea how many hours are on my tubes.  I know when I got them, so there is that, but now 3 years and 4 months later, is impossible for me to predict the hours.

I plan to use this hour counter as a guide.  Manufacturers such as Audio Research were of the opinion that it was a good feature to include on their later products, and I believe all of the amps from the Ref 110 and on include this function.

I of course agree that hours alone are not the only way to judge a tube or decide if an entire set should be replaced, but for me, this will be another piece of data that will enter into the evaluation of the situation.

A bonus feature, one can determine how long they fire up their systems per month, and if it is too infrequent, they will have a motivation to step it up!  Only 5 hours this month!?  I need to make my quota!  :-)
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cleeds
5,946 posts
 
https://www.audioaficionado.org/showthread.php?t=17941&highlight=volt+Hour+Meter
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