Yamaha THR10 - problems playing on battery power

Discussion in 'Digital & Modeling Gear' started by fataxeman, May 7, 2012.

  1. fataxeman

    fataxeman Member

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    My Yamaha THR10 cuts off completely after a few seconds when playing on battery power. This is the 2nd unit that has done this.

    I just exchanged it yesterday for a factory new unit, took fresh batteries that had maybe 45 minutes on them (bought new for this amp) and installed them in the brand new amp. Noodled away at the store for maybe 5 minutes and it never cut off. I crank it up this morning for the first time at home with the gain/master SLIGHTLY higher than I had it at the store and it cuts off in less than 5 seconds. If I lower the master and take it off the higher gain settings, it doesn't cut off as quickly, but still cuts off entirely. Dead. No sound. It does not fade out gradually, spit or sputter. No sir. It just stops instantly like you ripped the cable off of its tiny speaker(s).

    Nothing is different except the guitar/cord and my latitude/longituge. I connected the ac adapter and played for guitar 10 minutes at much higher gain/master settings and had ZERO problems. Also on this amp, just like the other one, when you plug in an ipod/ipad/c.d. player in to the auxiliary input and play music via battery power and at a higher volume level, there is NO problem. The issue is just playing guitar on battery power - the EXACT reason I bought this lovely little digital/computerized device.

    This does not make me happy. Does anybody have any ideas? I know the store will think I'm crazy. Hell, I think I'm crazy. The store said that they've sold 15 or so with no issues. May have to call Yamaha before contacting the store again.

    Update: Just tried the amp with 2 more guitars and 2 different cables. NO CHANGE in the problem!!!
     
    Last edited: May 7, 2012
  2. Tracy Evans

    Tracy Evans Member

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    Wow, how strange. I have only used my THR10 plugged in to AC. I haven't tried it with batteries yet, but I sure will now just in case.
     
  3. mmaatt25

    mmaatt25 Member

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    I've played my THR10 almost exclusively with batteries and have been getting a good 5-6 hours of playing out of it. I'm using eneloop batteries they are 2000mah but typically come in after a charge closer to 1800mah.
    The only thing I have in common is when the batteries go it dies instantly no warning, but that is to be expected.
    The PSU is 15vdc, 8 x AA batteries @ 1.5v is 14vdc. I haven't measured my dead batteries (no need) to see what the cut off voltage is, but it may be worth using a multimeter to check your batteries in the first instance, just incase you have a rogue one!!
     
  4. fataxeman

    fataxeman Member

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    I thought about checking the batteries with a meter but to summarize my post, even after the guitar output cut off in SECONDS, I played an ipod through the auxiliary input for nearly an hour at a LOUDER volume on the SAME BATTERIES.

    Makes no sense and by the way, 8 X 1.5 volts it 12 volts, not 14 vdc. I am never sure about the tolerances on a given piece of equipmnet. Does a pedal that has a 9 volt battery quit working when it will only supply 8 volts, 6 volts, somewhere in between?

    Personally, I think it is a design flaw. I may try some eneloop batteries but if they are 1.5 volts, that's still 1.5 volts. From what I can find online, eneloop batteries' claim to fame is that their self discharge rate is much slower than alkaline.

    Plus I'm not too keen on paying about 40 bucks or more for 8 batteries, even if they are rechargeable.

    It's not like I would be using battery power often but it needs to work for longer than 5 seconds when I do.
     
    Last edited: May 7, 2012
  5. Elmer

    Elmer hell is chrome Silver Supporting Member

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    FWIW, I played my THR10 today for about 20 minutes on some regular ol' Duracells. I don't know how long it would have gone for - some of the batteries were scrounged from remote controls and had to be returned to their rightful homes. :)

    Still, you should be able to get more than a few seconds from regular batteries. It sounds like something is definitely amiss.
     
  6. mmaatt25

    mmaatt25 Member

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    Yeah of course it's 12v:confused:

    Just take it back, get it replaced. I don't know whats wrong with it, but there is something definitely wrong.

    Don't worry about the shop, the item is defective end of conversation.
     
  7. msteeln

    msteeln Member

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    This is an important issue, certainly for those who will deffinitely be utilizing the battery option and count that ability as a great plus for even considering it's purchase. These are supposed to get 8 full hours of battery life, with no discrepency between value qualities. I should have mine tomorrow and will be checking out this situation immediately.
     
  8. msteeln

    msteeln Member

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    A net amp tech sez;
    "Sounds like the amp has a voltage sensing circuit that shuts down at a preset level. If the voltage drops below a certain point the transistors won't switch properly."
     
  9. presence

    presence Supporting Member

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    For what it's worth, I use mine regularly with batteries, no problem.

    Annoying problem, hope you're able get it sorted.
     
  10. gurumonkey

    gurumonkey Member

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    the only time i've been able to see any cut off problems was one time that i attempted to make the guitar feedback and it feedback at a very high frequency then shut off. otherwise it's played marvelous on battery power (i'm using eneloops.)
     
  11. KGWagner

    KGWagner Member

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    If you're using rechargeable batteries, they only produce 1.2 volts at full charge, not 1.5, which means you're only feeding 9.6 volts instead of 12. So, if there's anything digital about that unit, it may be sensitive to supply voltage and rather than the performance just deteriorating, it'll shut down altogether. Try putting some fresh (non-rechargeable) alkalines in there and see if that helps.
     
  12. Jack Gilvey

    Jack Gilvey Member

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    I haven't used batteries yet but Yamaha specifically recommends eneloops when using NiMH.
     
  13. presence

    presence Supporting Member

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  14. fataxeman

    fataxeman Member

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    Update: I got a call from Yamaha which in itself is encouraging. Talked to the guy and ran through the problem on the phone. I'm the first person in the world that has had this problem...or at least the first one to call about it.

    He said that playing the guitar through the amp took more current. That's not too surprising. But this thing is made to play the guitar and your ipod simultaneously if your little heart so desires, which would obviously take more current still.

    He wanted me to measure the collective voltage of the battery, says he will check with "the shop" and call me back. Haven't heard from him in a day and a half.

    Anyway, I was having a hard checking the battery voltage while installed in the amp so I take them out and line them up on the counter and measure the voltage. 11.2 volts. Seems pretty dang close to 12 volts to me. So what do you have to have, 11.7 volts or something to make this thing work?

    So, against all logic, I put in fresh batteries....just bought them Saturday at Home Depot. I open the pack put them in and, voila, it does not cut off 5 seconds in to my insane riffing....or 10 seconds. I turn it up a little louder and everything it still cool. I just spend a couple of mintues with it. That was yesterday. Today, I fire it up (gain control about 10 o'clock or so and master on about 1 o'clock). I don't even have to tell you that it started cutting off again.

    Yes sir, I can play a couple of minutes and then it's Silence City all over again. Maybe eneloop batteries are the answer. I wonder if Yamaha will send me about $80-100 to cover 8 batteries and a good charger.

    Good idea Yamaha. Too bad it doesn't work.
     
  15. fataxeman

    fataxeman Member

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    Even Newer Update: Not 10 minutes after typing this up, the Yamaha guy calls me.

    He verifies that there is a problem with a "voltage sensing circuit" and says "we're going back to Japan with this one." Apparently some of the circuits "trigger" more readily than others but the problem is, no doubt, bigger than that. (That's my analysis). So, they're sending the problem back to their engineers. Who knows what will happen with that. I'm not holding my breath so this amp may be going back this weekend. Shame.
     
  16. mmaatt25

    mmaatt25 Member

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    Your unit definitely has a problem, just exchange it.

    It must a a voltage sensing circuit that wants to see a minimum voltage to operate. In you r case this circuit for whatever reason is not functioning correctly. You have prooved this putting in a brand new set of batteries.

    I just measured the batteries in my THR10, which I'm expecting to need charging soon and they come in at 9.88Vdc.
    When it dies I'll measure the the batteries again and post the result.
     
  17. mmaatt25

    mmaatt25 Member

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    As promised they measured 9.06Vdc when it cut out.
     
  18. Jack Gilvey

    Jack Gilvey Member

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    Thanks for the info. How long did you get out of them?

    Yamaha says the amp "turns off automatically when battery power is depleted". As opposed to petering out like, say, a pedal might I guess.
     
  19. fataxeman

    fataxeman Member

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    Thanks for the info mmaatt25. At Master volume settings around 1 o'clock, mine is cutting off after a couple of minutes with the newer batteries....sooner if I turn the Master up a little more. I can turn it off for about 2 seconds and then turn it back on and it plays away like nothing ever happened....for a few seconds.

    The Yamaha guy called back and said that they opened a brand new unit, grabbed 8 used batteries from various drawers in the office and loaded 'em up. He said that they maxed out everything and played guitar with an ipod input in to the amp at the same time. He said that they went at it for 20 minutes until they "couldn't stand it anymore." The unit did not cut off; they just "completed" the test and quit.

    Yamaha person wants me to take the amp back to the store for an exchange (which will be my THIRD amp), have store call him for an RMA and ship the amp back to Yamaha so they can pull it's little guts out and see what is going on. There is a problem with the amp as a whole, but I seem to have been snakebitten TWICE! I'm glad it's not lightning!

    The saga continues...
     
  20. mmaatt25

    mmaatt25 Member

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    Playing for 1-2 hours an evening, seems to last 4-5 days, so I'd around 6 hours.

    It seems like it the voltage sensing circuit is looking for 9Vdc, if it doesn't see it it shuts down.

    The OP has replaced the batteries and measured 11.2Vdc with new so we can conclude that the voltage sensing circuit is faulty. Why it allows play for a few minutes remains a mystery!
     

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