# Amp Turn On Pop!



## stereo_luver (Oct 30, 2007)

I need a relay for my amp turn on. Any suggestions?

Chuck


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## minbari (Mar 3, 2011)

pac tr7


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## ecbmxer (Dec 1, 2010)

TR7 for sure. I just got one off ebay to fix the same problem for like $17 shipped.


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## spl152db (Dec 20, 2007)

Google

any bosch style relay. why use the pac?


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## minbari (Mar 3, 2011)

spl152db said:


> Google
> 
> any bosch style relay. why use the pac?


if all he needs is to turn on the amp, yes. but most likely he is gonna need to delay the amp turnon to avoid the pop he is hearing...........assuming the pop is not coming from the amp itself


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## spl152db (Dec 20, 2007)

minbari said:


> if all he needs is to turn on the amp, yes. but most likely he is gonna need to delay the amp turnon to avoid the pop he is hearing...........assuming the pop is not coming from the amp itself


so put in an inline resistor and call it a day. 99 cents at ratshack. delaying won't change anything if the amp is popping when it turns on.


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## minbari (Mar 3, 2011)

spl152db said:


> so put in an inline resistor and call it a day. 99 cents at ratshack. delaying won't change anything if the amp is popping when it turns on.


what is a resistor going to do? a resistor and a capacitor maybe. 

I did say, that if the amp is causing it wont help.


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## spl152db (Dec 20, 2007)

minbari said:


> what is a resistor going to do? a resistor and a capacitor maybe.
> 
> I did say, that if the amp is causing it wont help.


 sorry missed that part, but the resistor will cause a slow on. I've done it before with good results. it lowers the amperage. I = V/R ohms law.


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## minbari (Mar 3, 2011)

there is no guarantee though. more than likely there is a capacitor in the amplifier remote in line that the resistor playing nice with. 

amplifiers remoteline is a voltage sense line, slowing current wont do anything. take a resistor and put one end on 12V and the other on ground. it will be 12V instantly.


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## spl152db (Dec 20, 2007)

minbari said:


> there is no guarantee though. more than likely there is a capacitor in the amplifier remote in line that the resistor playing nice with.
> 
> amplifiers remoteline is a voltage sense line, slowing current wont do anything. take a resistor and put one end on 12V and the other on ground. it will be 12V instantly.


unless its designed poorly like rockford amps that will run off of the remote line if the amperage is available.


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## ecbmxer (Dec 1, 2010)

The resistor will not likely delay any appreciable amount. It will reduce the current (and cause a voltage drop), but electrons still flow at the same rate. The capacitor can, but it isn't gonna be much (depending on the RC circuit and R/C values). I spent a while looking at a bunch of options. You can build a circuit with a 555 IC timer, but its a PITA. At the end of the day, the TR7 is cheap and really versatile. 

OP: you should try some scenarios to see where the pop is coming from. Try unplugging the RCAs and see if it still pops when you turn on. Mine did. But if I unplugged the rem turn on lead, waited until the source unit was on, then plugged the rem turn on in to turn on the amp, no pop. That's why the TR7 is a good choice for my application.


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## minbari (Mar 3, 2011)

ecbmxer said:


> The resistor will not likely delay any appreciable amount. It will reduce the current (and cause a voltage drop), but electrons still flow at the same rate. The capacitor can, but it isn't gonna be much (depending on the RC circuit and R/C values).


if it is a series resistor, then it will slow down electrons, that is what a resistor does, slows current. as for the correct RC time constant. a 5kohm resistor with a 220uF shut cap will gie you 2 or 3 secs delay.

the TR7 is certainly the simplest solution.


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## SoundChaser (Apr 3, 2009)

As a bonus, with the PAC TR7 you can play video DVD’s while driving.


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## ecbmxer (Dec 1, 2010)

Well, thats why I'm an ME and not an EE lol. My thought was that while it will slow down the current through the resistor, some will still pass very quickly through the resistor and it might turn the amp on immediately vs a capacitor which has a charging delay. Would the voltage drop across your suggested RC values be enough that the amp might not come on?


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## minbari (Mar 3, 2011)

nope, you could put a 1Mohm resistor and a 1 farad cap in an RC circuit and it would take hours to charge, but it would come on eventually, lol.


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## sqshoestring (Jun 19, 2007)

If it is the amp nomatter what, you can do the following or buy a product that does. 

You can put a relay on the output of the amp, delay it, and it would be off when the turn on pop happened, then will turn on to connect the speakers. Many class D do this internally to wait until the amp is running properly after startup. If a multi ch amp then put on the powered terminals not the common; put the relays on the terminals used for bridging the others will be the common you don't need to do.

You can use resistors and caps to delay, it should be easier to do this with a relay that has a known current to activate its coil. Many amps you are powering up a little transistor in the startup circuit and hard to know what values are going to affect it like you want. However there was a guy here that just put a cap on his HU remote wire to keep it running when he started the car and give a little delay after key off, and it worked fine with nothing else.


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## stereo_luver (Oct 30, 2007)

The pop is due to the signal from the HU when a source is activated.

Turn on HU and the amps turn on instantly.
When the HU recognises the source and it switches internally the pop occures.
You can hear the relay within the HU switch...then a pop from the amps.
Change sources and it will do it again. Its VERY faint and you really have to listen for it closely and anticipate it.
Everyday use and NOT listening very closely.....you never hear it.
Judges check this issue and listen VERY closely for ANY noises.


I never heard it until I climbed in the truck with a judge and he pointed it out to me. We even saw that the amps were already turned on and isolated when the pop happened. They only check for the initial pop when the key is turned on. So when this happens if the source is changed it isn't checked. Only checked when the system is first turned on. However they do listen for a pop when the system is turned off. I have no issue with that.

I need a relay with an adjustable delay time.

Chuck


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## jtaudioacc (Apr 6, 2010)

I often use a Stinger SGN21. It's easy, doesn't need to be programmed. Has wiring for both on and off pop.

TR-7's are great, too. But for a simple pop, I like using the Stinger piece.


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## JJDu4 (Jun 8, 2011)

we usually just throw in a Stinger SGN21 too!


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## estione (Jul 24, 2009)

I'd rather find out why it's "popping" first ie; like checking all the earth's and if it's a pioneer h/unit checking the rca's and earth track's etc, etc before i would add another item to the install


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## ecbmxer (Dec 1, 2010)

stereo_luver said:


> The pop is due to the signal from the HU when a source is activated.
> 
> Turn on HU and the amps turn on instantly.
> When the HU recognises the source and it switches internally the pop occures.
> ...


Thats the exact same thing I have. If you test it by unplugging the RCAs, it will probably not pop. I need a 3-5 sec delay for mine. That stinger unit would be great if a 1sec delay was what was needed.


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## ecbmxer (Dec 1, 2010)

Did you ever fix your turn on pop? I found out that mine is still present WITHOUT the RCAs connected and it doesn't matter if I delay the turn on. I'm looking into grounds and then will replace my amps as a last resort.


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