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    Amplifier hour meter - very useful

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    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Amplifier hour meter - very useful

    Post by Bob Latino on Tue Jun 28, 2016 10:40 am

    I have a customer who added an appliance "hour meter" to his VTA ST-120 to monitor the number of hours his amp has been on. This would be a very useful addition to your amp. Unfortunately, it does not fit on the amp itself but he houses the meter in a small plastic box. His amp is just about 2 years old and he mentioned that he and his wife listen to the amp almost every day for a few hours.  He lamented to me that he probably should have been checking the hour meter more often. At a little over 3200 hours one of the output tubes went up in smoke and took out two of the 100 ohm 1 watt resistors on the triode/pentode ultralinear switches.

    The meter he used is from > http://www.mpja.com/

    It is their model # > Stock #: 32407ME and costs > $14.95. He housed the meter in a plastic box also available from the same vendor > Stock #: 15520BX which costs $3.95.

    They have a Youtube video that shows this meter and it's other functions below ...



    There are other hour meter out there. I have seen them on Ebay before ..

    Output tubes in the VTA amps should last 3000 - 4000 hours. The driver tubes maybe 5000 hours. Depending on how often you use your amp, sometimes after 2 to 4 years, you should should consider replacing at least the OUTPUT tubes. Keep the old output tubes as spares to maybe use in an emergency to keep the music flowing if you do run into a tube problem. I always advise to also keep a spare rectifier for your amp around at all times. Rectifiers take a lot of high voltage "abuse" (300+ volts on pins 2, 4, 6 and 8 ) and are the tube most likely to die on your amp.

    Bob

    maritan

    Posts : 3
    Join date : 2016-06-23

    Re: Amplifier hour meter - very useful

    Post by maritan on Tue Jun 28, 2016 12:57 pm

    Oh, this is nice. This should work on any amp really - including the VTA-70 and the M-125 (one per block).

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Amplifier hour meter - very useful

    Post by deepee99 on Tue Jun 28, 2016 3:16 pm

    Bob,
    If I gather correctly from the video, the meter re-sets every time the power is shut off. Is there a way to get a cumulative read, like the Hobbes meters on an aircraft engine, so you know the total time on the tubes? In other words, when the magnetos are on the clock is running, stops when you turn the master-switch off, but picks up where it left off next time you light the fires until you manually zero it out. Or did I miss a step?
    I keep a hand-write log that approximates TT, but it would be nice to have an instrument that did the same with more precision. Would also be useful to time caps, resistors, rectifiers as you say, as to when they fail.
    Ideas?


    Last edited by deepee99 on Tue Jun 28, 2016 3:23 pm; edited 1 time in total (Reason for editing : clarity)

    peterh

    Posts : 643
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Amplifier hour meter - very useful

    Post by peterh on Tue Jun 28, 2016 3:17 pm

    I have used :
    http://www.ebay.com/itm/121052465515?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

    for close to 2 years now. Simular price but less buttons and size. I power it from +12V used to control the SSR in the vta70.

    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Amplifier hour meter - very useful

    Post by Bob Latino on Tue Jun 28, 2016 3:23 pm

    deepee99 wrote:Bob,
    If I gather correctly from the video, the meter re-sets every time the power is shut off. Is there a way to get a cumulative read, like the Hobbes meters on an aircraft engine, so you know the total time on the tubes? Or did I miss a step?
    I keep a log that approximates TT, but it would be nice to have an instrument that did the same with more precision. Would also be useful to time caps, resistors, rectifiers as you say, as to when they fail.
    Ideas?



    David,

    That hour meter does not reset unless you MANUALLY rest the meter. If you run the amp (or whatever load you place on the meter) for four hours one day and two hours the next day, the meter will read 6 hours. Again > That hour meter does not reset unless you MANUALLY rest the meter to zero.

    Bob

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Amplifier hour meter - very useful

    Post by deepee99 on Tue Jun 28, 2016 3:33 pm

    Bob Latino wrote:
    deepee99 wrote:Bob,
    If I gather correctly from the video, the meter re-sets every time the power is shut off. Is there a way to get a cumulative read, like the Hobbes meters on an aircraft engine, so you know the total time on the tubes? Or did I miss a step?
    I keep a log that approximates TT, but it would be nice to have an instrument that did the same with more precision. Would also be useful to time caps, resistors, rectifiers as you say, as to when they fail.
    Ideas?



    David,

    That hour meter does not reset unless you MANUALLY rest the meter. If you run the amp (or whatever load you place on the meter) for four hours one day and two hours the next day, the meter will read 6 hours. Again > That hour meter does not reset unless you MANUALLY rest the meter to zero.

    Bob
    Many thanks. That feature was not emphasised in the video, or I missed it. Think I'll get me a couple, one for each amp as we don't always replace output tubes at the same moment, though if one side is going saggy I figger the other one's probably near broke, too, and just install 8 new outputs.
    Off-topic, the Shuguang and PSVanes are performing wonders. Next paycheck from Uncle Sugar, am going to try out their KT-88s. FWIW, from a major and very reliable dealer of these bottles in China, let me pass along the following.
    "Hello!
    I am happy see your message.
    Psvane and ShuGuang we talk about it now.
    Psvane have three series. Price from low to high is:
    HIFI,
    Mark-II,
    Re-edition Classics

    ShuGuang have four series.Price from low to high is:
    General Series,
    Black Treasures,
    Sound Of Nature
    Re-edition Classics

    ShuGuang earlier than Psvane was born.First they are same factory and same technical personnel.
    Now Psvane has been out of ShuGuang and It's an independent brand.
    You said KT88 and 6SN7.
    ShuGuang's General Series KT88-98 have the most stable performance and price is not high.
    6SN7 which one is better hard to say.
    If Psvane and ShuGuang comparison of the same level is can't say better or bad.
    Because every tube and every amp is different.They parameter is different.Personal preference also different.
    But high level's material is better than general."
    Maybe this belongs in a new thread, but just wanted to pass his wisdom along.





    Kentley

    Posts : 300
    Join date : 2015-03-06
    Age : 64
    Location : Worcester, MA

    Re: Amplifier hour meter - very useful

    Post by Kentley on Tue Jun 28, 2016 8:52 pm

    Gotta love the Chinese - English must be even more difficult to grasp than Chinese for us, yet as awkward as the translation is, the author manages to make himslf clear enough.
    I'm surprised to see two levels of ShuGuangs ABOVE Black Treasure. I've never seen them on any market. If they are superior to the BTs ---

    Praise the Load, and pass the MasterCard!

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