LSi25 plate amp question

When I’m running my LSi 25s, the plate amp gets really, REALLY hot, even when it is just switched to on, or I am using it at low volumes. Is this normal? No other plate amplifier that I have dealt with gets this hot, at least as far as I can remember. I will give you guys a exact temperature later, but I’d say it’s probably around 100-110* F. The other amp doesn’t work so I can’t compare it to what is happening to this one. It seems like it would be bad for the amplifier to be this hot all the time, but maybe I’m wrong. Also, this is the temperature on the heat sink, not in the amplifier. It usually is still slightly warm when it is set to auto and it has turned itself off, however when I switch it to off, it becomes cold again (obviously, if it’s doing nothing, it’s not getting hot). Anyway, is this normal, and if not, is it something I can fix?

Thanks again for your help,
Micah
2 channel
Speakers: Mission 770 Freedoms
Integrated amp: Technics SU-v75 and matching tuner
CDP: Technics SL-PC20
Cables: Monoprice, Monster, Acoustic Research, and a few generic ones
TT: Technics SL-3200, direct drive
Cartridge: Shure M97xE

Pc gaming setup
Receiver/amp: Yamaha RX-V665
Computer: Lenovo g50 (soon to be upgraded to a Dell Precision 690 which is far from stock!!)
Interconnects: Amazon basics HDMI, Acoustic Research HDMI, Monoprice speaker cables
Speakers: Boston Acoustics CR75s

Random equipment on standby:
Onkyo TX-v940, JBL woofers and tweeters, single Klipsch KG .5, Yamaha guitar amplifier, Peavey Rage 158 guitar amplifier, Kicker comp 12” subwoofer, single Bose 802 series II, a whole bunch of 1”-3” full range drivers, Infinity Crescendo 3007s (on sale), Polk LSi25s
txcoastal1 wrote: »

You don't tell her you read the manual, and you tell her you know what the problem is, and you fixed it, because that what men do, fix things
sure it has a flat response, and sure it has a lot of detail, and yes, it has good and clear lows. But is it enjoyable to listen to? Does it make you grin ear to ear? That’s what really matters.
Seen somewhere on AudioKarma (I think)

Comments

  • tonybtonyb Posts: 29,057
    Doesn't seem all that hot to me, but the speakers are old so I'd imagine sooner rather than later you'll be needing new ones or rebuilding the old, if your that handy.

    Make sure the rear of the speaker isn't up against a wall also, give it some room to breath.
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  • KennethSwaugerKennethSwauger Moderator Posts: 6,404
    Hello Micah,
    It is possible the amp's bias is set too high causing the higher temperature. This is similar to having a car's engine idling too high. Usually as long as you can place your hand on the input plate without discomfort there's no case for concern. On most amps there's an adjustment potentiometer and a place to measure in setting the bias. Since you have one amp not working you might contact Polk to see what service is available. They are at 1-800-377-7655 assuming you live in the U.S.
    "And the house you live in will never fall down
    If you pity the stranger who stands at your gate" G.Lightfoot
  • mlistens03mlistens03 Posts: 986
    I have contacted Polk regarding the broken amp, and I am going to send it to them (or possibly a 3rd party person, but probably Polk,) to get it fixed, I just haven’t gotten around to it yet. As for the other amp, how do I adjust its bias? Is there a switch inside? And how do I measure it?

    Thanks again for your help,
    Micah
    2 channel
    Speakers: Mission 770 Freedoms
    Integrated amp: Technics SU-v75 and matching tuner
    CDP: Technics SL-PC20
    Cables: Monoprice, Monster, Acoustic Research, and a few generic ones
    TT: Technics SL-3200, direct drive
    Cartridge: Shure M97xE

    Pc gaming setup
    Receiver/amp: Yamaha RX-V665
    Computer: Lenovo g50 (soon to be upgraded to a Dell Precision 690 which is far from stock!!)
    Interconnects: Amazon basics HDMI, Acoustic Research HDMI, Monoprice speaker cables
    Speakers: Boston Acoustics CR75s

    Random equipment on standby:
    Onkyo TX-v940, JBL woofers and tweeters, single Klipsch KG .5, Yamaha guitar amplifier, Peavey Rage 158 guitar amplifier, Kicker comp 12” subwoofer, single Bose 802 series II, a whole bunch of 1”-3” full range drivers, Infinity Crescendo 3007s (on sale), Polk LSi25s
    txcoastal1 wrote: »

    You don't tell her you read the manual, and you tell her you know what the problem is, and you fixed it, because that what men do, fix things
    sure it has a flat response, and sure it has a lot of detail, and yes, it has good and clear lows. But is it enjoyable to listen to? Does it make you grin ear to ear? That’s what really matters.
    Seen somewhere on AudioKarma (I think)
  • mlistens03mlistens03 Posts: 986
    edited February 22
    Tony, it’s not up against the wall, The heat sink is about 4-5 inches from the wall, and the speaker is pointing towards me (probably around 75 degree angle, but I have no idea, that is just a rough estimate).
    2 channel
    Speakers: Mission 770 Freedoms
    Integrated amp: Technics SU-v75 and matching tuner
    CDP: Technics SL-PC20
    Cables: Monoprice, Monster, Acoustic Research, and a few generic ones
    TT: Technics SL-3200, direct drive
    Cartridge: Shure M97xE

    Pc gaming setup
    Receiver/amp: Yamaha RX-V665
    Computer: Lenovo g50 (soon to be upgraded to a Dell Precision 690 which is far from stock!!)
    Interconnects: Amazon basics HDMI, Acoustic Research HDMI, Monoprice speaker cables
    Speakers: Boston Acoustics CR75s

    Random equipment on standby:
    Onkyo TX-v940, JBL woofers and tweeters, single Klipsch KG .5, Yamaha guitar amplifier, Peavey Rage 158 guitar amplifier, Kicker comp 12” subwoofer, single Bose 802 series II, a whole bunch of 1”-3” full range drivers, Infinity Crescendo 3007s (on sale), Polk LSi25s
    txcoastal1 wrote: »

    You don't tell her you read the manual, and you tell her you know what the problem is, and you fixed it, because that what men do, fix things
    sure it has a flat response, and sure it has a lot of detail, and yes, it has good and clear lows. But is it enjoyable to listen to? Does it make you grin ear to ear? That’s what really matters.
    Seen somewhere on AudioKarma (I think)
  • KennethSwaugerKennethSwauger Moderator Posts: 6,404
    "how do I adjust its bias? Is there a switch inside? And how do I measure it?"

    Let me contact my friend, at Polk, and see what he knows.
    "And the house you live in will never fall down
    If you pity the stranger who stands at your gate" G.Lightfoot
  • KennethSwaugerKennethSwauger Moderator Posts: 6,404
    They are checking to see.
    "And the house you live in will never fall down
    If you pity the stranger who stands at your gate" G.Lightfoot
  • mlistens03mlistens03 Posts: 986
    Ok, thanks!
    2 channel
    Speakers: Mission 770 Freedoms
    Integrated amp: Technics SU-v75 and matching tuner
    CDP: Technics SL-PC20
    Cables: Monoprice, Monster, Acoustic Research, and a few generic ones
    TT: Technics SL-3200, direct drive
    Cartridge: Shure M97xE

    Pc gaming setup
    Receiver/amp: Yamaha RX-V665
    Computer: Lenovo g50 (soon to be upgraded to a Dell Precision 690 which is far from stock!!)
    Interconnects: Amazon basics HDMI, Acoustic Research HDMI, Monoprice speaker cables
    Speakers: Boston Acoustics CR75s

    Random equipment on standby:
    Onkyo TX-v940, JBL woofers and tweeters, single Klipsch KG .5, Yamaha guitar amplifier, Peavey Rage 158 guitar amplifier, Kicker comp 12” subwoofer, single Bose 802 series II, a whole bunch of 1”-3” full range drivers, Infinity Crescendo 3007s (on sale), Polk LSi25s
    txcoastal1 wrote: »

    You don't tell her you read the manual, and you tell her you know what the problem is, and you fixed it, because that what men do, fix things
    sure it has a flat response, and sure it has a lot of detail, and yes, it has good and clear lows. But is it enjoyable to listen to? Does it make you grin ear to ear? That’s what really matters.
    Seen somewhere on AudioKarma (I think)
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