Hours Run Meter for valves

[bob4333]

I've just ordered a new set of valves for my phono stage and the thought occurred to me that I don't really know how long the existing set has lasted. The sound is now changeable with a bit of occasional spitting thrown in and clarity has gone right down the pan. I bought it as a minty 3 month old ex dem unit but have no idea as to it's use before I got it.

I could write down the on/off times of each session but that's a lot of hassle and I'm sure to miss a few so with the best will in the world it'd be vague at best.

I need an "hours count up timer" that can be started / stopped at the touch of a button, a bit like a kitchen timer. I've seen them for things like tractor and boat engines but they trigger off a spark plug. Kitchen timers I've seen don't go high enough: valve life is quoted as 3000 - 5000 hours by the manufacturer so a much higher count is required.

What does everyone else do?

Something simple would be fine. Best I've found so far goes to 99 hours. Anyone seen something better?

[NRG]

It may not be the valve. First try reseating them to make sure the connections are OK.

Small signal valves, depending on how hard they are run, should last in the region of 10,000 hours, if used for 4 hours every day of the year it works out to just under 7 years use. TBH I would not worry so much! ;) If you feel you must change them then go ahead and then mark your calendar for a swap out in 5 years time.... :)

[DSJR]

Line valves should have around 10,000 hours on them I think from memory if they're used properly and output valves depend on make, and the way the circuit drives them.. My Quad II's have three original GEC KT66's from 1962 and the fourth only blew due to ageing internals, now sorted thanks to Glenn's work many years ago. A Tube Technology Genesis Mono pair, over-driving a quad each of EL34's, ate the originals in a year of use. Maybe cutting the bias/grids down a bit to reduce power and/or using higher rated output tubes would have drastically improved longevity of these things I don't know..

My twently plus year old Croft preamp was suppiled to me with grotty line valves, suspect phono stage ones (two per channel in mine) and the power supply valves were on the way out as well, although not badly. The internals of the preamp had loads of dust inside (open fine-mesh top grille) and I suspect the thing had many thousands of hours use behind it when I bought it a few years ago - shows how well used and loved Glenns products tend to be :) Over the next couple of years, I replaced all the valves and the preamp is now a pretty transparent view on the signal fed it and has remained stable since...

So to conclude, may I suggest getting decent replacements (vintage tubes can be more coloured sounding than later ones, but it can be fun fine tuning to suit) and making sure the basic unit isn't over-driving them..

[walpurgis]

I've never had a valve 'wear out' or show audible signs of deterioration.


Just found this free app which may help:
http://download.cnet.com/XNote-Timer/3000-2350_4-10912167.html?tag=mncol;4

There are loads of free ones on download.com, just search' timer clock', they have varying facilities.

[bob4333]

It may not be the valve. First try reseating them to make sure the connections are OK.

Small signal valves, depending on how hard they are run, should last in the region of 10,000 hours, if used for 4 hours every day of the year it works out to just under 7 years use. TBH I would not worry so much! ;) If you feel you must change them then go ahead and then mark your calendar for a swap out in 5 years time.... :)

The point you make is fair so thanks. I'd already tried pushing them gently into their socket to make sure they were seated OK but I suppose taking them out and cleaning the connectors wouldn't go amiss.

I'll give it a go later today and see if I get a fix.

[bob4333]

Line valves should have around 10,000 hours on them I think from memory if they're used properly and output valves depend on make, and the way the circuit drives them..
Maybe cutting the bias/grids down a bit to reduce power and/or using higher rated output tubes would have drastically improved longevity of these things I don't know..

So to conclude, may I suggest getting decent replacements (vintage tubes can be more coloured sounding than later ones, but it can be fun fine tuning to suit) and making sure the basic unit isn't over-driving them..

Thanks. I'm far from expert on valve stuff - I just like the sound of this particular stage. Regarding valve life the manual states:-

".... life will depend on hours of use and the number of on/off cycles. A valve may be considered to have come to the end of it's life when the sound quality has changed or it has become noisy and or microphonic...... As a rough guide we would expect around 3000 - 5000 hours per set. It is worth noting that this application is very demanding from the ECC83 valves"

There are also a few other bits in there but it comes as close as makes no odds to describing what's happening.

It's an Icon Audio PS 1.2 and has 3xJJ ECC83's. I'm not looking to burn cash but as it's the first time I'm changing them I've ordered the replacements direct from David Shaw. At £15 a shout it's not the end of the world and they do come tested and matched. If it turns out to be something else (like reseating) then I have a set standing by for when they do go pop. If I'm not yet at 3000 hours I guess I'm close and then there's it's early life to add on. I just don't know.

But I'll try cleaning the contacts first.

[bob4333]

I've never had a valve 'wear out' or show audible signs of deterioration.


Just found this free app which may help:
http://download.cnet.com/XNote-Timer/3000-2350_4-10912167.html?tag=mncol;4

There are loads of free ones on download.com, just search' timer clock', they have varying facilities.

Only person left in the world with no smart phone, and the PC / Networking stuff stays switched off when it's vinyl time.

I was thinking about something a bit more physical that could be left by the on / off switch and used as and when.......

[ninedecks]

Ideally you would want a clock that is physically powered by the amp itself.
I know nowt about electrickery but when switched on, is there a measurable voltage at the speaker plug outlet of the amp?.
If so would it be possible to connect a very low voltage clock to the output without reducing the power to the speakers. Sorry if this is a naive 'look' on amps.
Dave

[Firebottle]

What you need is a 'run time meter' or 'hour meter'.
Here are some links:
http://www.plumbcenter.co.uk/en/heating/domestic-controls-valves/grasslin-uwz-48a-surface-hour-run-meter-240v-59696

http://www.kep.com/catalog/ii/pages/products/H57-hour-meter.html

http://www.europacomponents.com/product_desc.php?prd_id=828

http://compare.ebay.co.uk/like/200797837065?var=lv&var=sbar&_lwgsi=y&cbt=y&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=66&ff19=0

The last one on ebay is a comparison so should give good food for thought.

You would need to power it only when the amp is on, via any switched mains outlet would be the easiest way.

:cool:Alan

[bob4333]

Ideally you would want a clock that is physically powered by the amp itself.
I know nowt about electrickery but when switched on, is there a measurable voltage at the speaker plug outlet of the amp?.
If so would it be possible to connect a very low voltage clock to the output without reducing the power to the speakers. Sorry if this is a naive 'look' on amps.
Dave

The connection goes cartridge/arm to phono-amp to pre-amp to power-amp to speakers.

The phono-amp has a separate power supply activated by a simple flick switch. This would seem a logical place to take a trigger from but it's not something I'm about to mess with without a lot more understanding than I currently have (as it's 240v at this point and likely to do more than just tickle me).

Your idea's bang on though.

[bob4333]

What you need is a 'run time meter' or 'hour meter'.
Here are some links:
http://www.plumbcenter.co.uk/en/heating/domestic-controls-valves/grasslin-uwz-48a-surface-hour-run-meter-240v-59696

http://www.kep.com/catalog/ii/pages/products/H57-hour-meter.html

http://www.europacomponents.com/product_desc.php?prd_id=828

http://compare.ebay.co.uk/like/200797837065?var=lv&var=sbar&_lwgsi=y&cbt=y&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=66&ff19=0

The last one on ebay is a comparison so should give good food for thought.

You would need to power it only when the amp is on, via any switched mains outlet would be the easiest way.

:cool:Alan

Yes, I had looked at the mains powered options and the ones you quote look pretty good. I was hoping to find something cheap/plasticky/AA battery powered that doesn't require plumbing in or major surgery. Something that doesn't turn into a major project in it's own right if at all possible.

Next time I break my system down for cleaning I'll take a look inside the power supply and see what in theory could be done. I'm not going to get neurotic over counting the hours - but thought it'd be good to do if it could be done simply.

Thanks for the links.

[DSJR]

Icon Audio are good people I understand and are readily available for advice on valve type and replacement. I'm shooting in the dark here, but mil-spec valves may possibly have a longer life - why not ask them? ECC83's are common as muck and there are still many varients you could sucessfully tery I think. Again, as the distributor/manufacturer...

[bob4333]

Icon Audio are good people I understand and are readily available for advice on valve type and replacement. I'm shooting in the dark here, but mil-spec valves may possibly have a longer life - why not ask them? ECC83's are common as muck and there are still many varients you could sucessfully tery I think. Again, as the distributor/manufacturer...

I agree about Icon Audio and have spoken to them in the past - refreshingly helpful whether you're buying or not. At present I'm just looking to get the performance back that seems to be edging away - which is why I went back to the manufacturer for replacements.

I've just found a battery driven 100 hour timer for £6 delivered so will start with that. Still need to manually track every 100 hours though but it's better than continually writing down start/stop times. http://www.ebay.co.uk/itm/260836906759?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648#ht_770wt_969

There was a 1000 day timer direct from China that I thought I could make work until I tried to read the instructions.............