# What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does it



## xtremevette (Apr 14, 2011)

*What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does it*

So Iam having trouble with a Planet Audio 5 channel amp. I love the sound but just can't seem to get rid of an annoying turn on & turn off pop and thump.

All speakers pop and my sub I can see gets sucked in and makes a thump whenever the amp starts up or shuts down. I have tried 2 different grounds both to chassis. Neither helps. I thought it was a blown DSP/graphic eq but when I wire the amp directly to my head unit I get the same thing. I even tried to leave the remote wire off the amp and triggered it after all my other equipment powered up. Still the sub gets sucked in and thumps once the amp completes its power up. I don't have any RCA's plugged in. So does this sound like something is spiking down the power or ground lines and getting amplified by my 5 channel? or Does this sound like a remote turn on issue?

Need some help and to point me in the right direction. I know it has to do with something with the amp because I have installed 2 of these now and they both behaved the same way. With other amps I don't have this problem. So how do you get rid of this problem on an amp that is particularly picky and pops.


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## gckless (Oct 11, 2012)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*

Many times it's your amp's ground. Is your connection at a good point in the car, solid and paint-free? You may want to try moving it. But it may just be the amp itself.


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## minbari (Mar 3, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*

all amps pop and thump on turn-on and off, but they ussualy have muting circuits that delay output to the speakers until the power supply is stable.

is this an old school planet audio or one of the new ones?


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## basshead (Sep 12, 2008)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*

Design flaw or bad components inside the amp IMO


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## xtremevette (Apr 14, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



gckless said:


> Many times it's your amp's ground. Is your connection at a good point in the car, solid and paint-free? You may want to try moving it.


Yes very solid and completely paint free. Attached with a very good quality crimp connector with a bolt, lock washer and nut. Both places I tried for grounds had it done this way.


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## xtremevette (Apr 14, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



minbari said:


> all amps pop and thump on turn-on and off, but they ussualy have muting circuits that delay output to the speakers until the power supply is stable.
> 
> is this an old school planet audio or one of the new ones?


one of the new ones. Make that 2. I had one...thought it was a bad amp...Bought another...it too does the same exact thing. It is suppose to have a soft turn on/off circuit in it. I love the sound...just hate the pops.


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## xtremevette (Apr 14, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*

I read this....anybody know where I can get these "relays" for the speaker output leads?

My problem exists with no rca's plugged in...therefore:



> If problem is present with no RCAs, there is really only one thing you can do, the pop is being generated by the amplifier. put relays on the speaker outputs and delay turning on the relays by a couple seconds. the pop will occur, but never make it to the speakers.


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## minbari (Mar 3, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*

^^^^ that is about all you can do if you want to keep the amplifier. the trick with using relays, if you have to make a circuit for "last one, first off" 

you want the relays off until the amplifier is fully on, then switch. when you turn off, you want the relay off first, then the amplfiier. this keeps both thumps out of the speakers.

have you ever noticed home audio recievers? you turn them on and they go through a startup. the relays dont attach the speakers until the amplifier is up, then they disconnect the speakers first.


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## minbari (Mar 3, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



xtremevette said:


> one of the new ones. Make that 2. I had one...thought it was a bad amp...Bought another...it too does the same exact thing. It is suppose to have a soft turn on/off circuit in it. I love the sound...just hate the pops.


supposed to? there is no law  but better amplifiers do have soft turn-on and turn-off.


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## xtremevette (Apr 14, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



minbari said:


> ^^^^ that is about all you can do if you want to keep the amplifier. the trick with using relays, if you have to make a circuit for "last one, first off"
> 
> you want the relays off until the amplifier is fully on, then switch. when you turn off, you want the relay off first, then the amplfiier. this keeps both thumps out of the speakers.
> 
> have you ever noticed home audio recievers? you turn them on and they go through a startup. the relays dont attach the speakers until the amplifier is up, then they disconnect the speakers first.


Ok and yes I have noticed that from home amps. Is there a place that sells these relays that I need to add to my speaker leads. I don't have any experience with building stuff/relays like this.


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## minbari (Mar 3, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*

there is nothing special about the relays. DPDT or 4PDT will work just fine. you just need 1 pole for each speaker. the part that is not "off the shelf" is the control hardware.

the miniDSP isolated power supply has this feature biult in. you could get one of those and just use the RTO in and out feature to turn the relays on and off. its only $12.


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## xtremevette (Apr 14, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



minbari said:


> there is nothing special about the relays. DPDT or 4PDT will work just fine. you just need 1 pole for each speaker. the part that is not "off the shelf" is the control hardware.
> 
> the miniDSP isolated power supply has this feature biult in. you could get one of those and just use the RTO in and out feature to turn the relays on and off. its only $12.


Sorry to sound stupid...but I have no clue what your talking about. 

I think I know what the DPDT is (dual pole dual throw?) and possibly the 4PDT (4 Pole Dual throw?)

Not sure what you mean by 1 pole for each speaker (does that mean the positive wire goes to a pole? Where do the negative wires go to?)

Also what do I need for control hardware?

The MiniDSP never heard of.

No idea what a RTO is.

You would be helping me out immensely if you could give me a link, pictures or item numbers to what I need and what wires go to what. All I know is Iam assuming I take the speaker output leads from the amp and they must get connected to something and then there would be outputs from that that go to the speakers? Do these relays need to be a certain size to accomodate the wattage being on the speaker lines? Obviously my sub line would be more then the other speakers. My sub output is around 500 rms mono. The speakers are around 150 rms X 4.


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## minbari (Mar 3, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



xtremevette said:


> Sorry to sound bad...but I have no clue what your talking about. I think I know what the DPDT is (dual pole dual throw?) and possibly the 4PDT (4 Pole Dual throw?). Not sure what you mean by 1 pole for each speaker (does that mean the positive wire goes to a pole? where do the negative wires go to?) Also what do I need for control hardware? The MiniDSP never heard of. No idea what a RTO is. You would be helping me out immensely if you could give me a link, pictures or item numbers to what I need and what wires go to what. All I know if Iam assuming I take the speaker output leads from the amp and they must get connected to something and then there would be outputs from that that go to the speakers? Do these relays need to be a certain size to accomodate the wattage being on the speaker lines? Obviously my sub line would be more then the other speakers. My sub output is around 500 rms mono. The speakers are around 150 rms X 4.


a "pole" in relay speak is essentially a connection. you are right with your interpretation of DPDT, 4PDT. a "dual pole, dual throw" means that you have two separate switches that have access to the "normally open" AND "normally closed" states. This describes how the relay contacts behave in the "off" and "on" conditions.

you would only need to cut the positive OR negative wire for each speaker, this would cut the connection to the amplifier until the relay was turned on. (thus needing 1 pole for each speaker) leave the other wire connected as is.

DPDT Relay Switch | Double Pole Double Throw Relay - EngineersGarage

This is the miniDSP device I was refering to. (they have alot of other cool stuff too  )
RTO = Remote turn on.

miniDC Isolator | miniDSP

yes, the relays have to be able to handle the current being given to the speakers.
the 150 watt channels, a 20 amp relay would work, the 500 watt channel would require 30 amps. (you can use 30 amp relays all around too)

This one would work. you would have to wire 1 for each speaker.
T9AS1D22-12 - TE CONNECTIVITY / POTTER & BRUMFIELD - POWER RELAY SPST-NO 12VDC, 30A | Newark


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## xtremevette (Apr 14, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



minbari said:


> a "pole" in relay speak is essentially a connection. you are right with your interpretation of DPDT, 4PDT. a "dual pole, dual throw" means that you have two separate switches that have access to the "normally open" AND "normally closed" states. This describes how the relay contacts behave in the "off" and "on" conditions.
> 
> you would only need to cut the positive OR negative wire for each speaker, this would cut the connection to the amplifier until the relay was turned on. (thus needing 1 pole for each speaker) leave the other wire connected as is.
> 
> ...


Ok so I see everything but have no clue how to build the whole thing. Want a job? Iam serious. If your interested I would like you to build me what I would need for the 5 channels. Just let me know what I would be looking at for a price.

This won't compromise the sound quality will it? 

Can I wrap the whole things up with electrical tape or what do I do to have them not be exposed to shorts/accidentally touch something. Iam guessing they must throw off some heat as well.


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## minbari (Mar 3, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



xtremevette said:


> Ok so I see everything but have no clue how to build the whole thing. Want a job? Iam serious. If your interested I would like you to build me what I would need for the 5 channels. Just let me know what I would be looking at for a price.
> 
> This won't compromise the sound quality will it?
> 
> Can I wrap the whole things up with electrical tape or what do I do to have them not be exposed to shorts/accidentally touch something. Iam guessing they must throw off some heat as well.


if you want to buy me the parts and have them sent to my house, I would build it for ya for $25. Pm me for a parts list.

nope, wont effect sound quality at all. relay is just a switch.

up to you, but I would put the whole thing in a small plastic project box, relays dont produce much heat at all. not enough to worry about.


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## MarkZ (Dec 5, 2005)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*

If it's an older amp, it probably needs a cap job. Asymmetries in the power supply find their way to the outputs during turn on, turn off, or both. I had an amp that used to squeel during turnoff as the caps were discharging.

Before you do the relay thing, first measure the DC output of the amp at idle just to make sure something funky isn't going on. It shouldn't be higher than the single or double digit mV range.


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## xtremevette (Apr 14, 2011)

*Re: What causes an amp to pop on turn on & turn off? No RCA's plugged in...still does*



MarkZ said:


> If it's an older amp, it probably needs a cap job. Asymmetries in the power supply find their way to the outputs during turn on, turn off, or both. I had an amp that used to squeel during turnoff as the caps were discharging.
> 
> Before you do the relay thing, first measure the DC output of the amp at idle just to make sure something funky isn't going on. It shouldn't be higher than the single or double digit mV range.


Will do and minibari thanks...ill get back to you once I do what markc suggested


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