Loud Snapping sound when using 12V Trigger to turn on and off Power amp

V

Vignesh

Audiophyte
I have a Marantz 7704 pre amp and a Monolith power amp. I am using XLR cables to connect the preamp to the power amp. When I manually turn on and turn off the system in the right sequence everything is fine but when I use the 12v trigger to the power amp I am hearing a very loud pop/snap from one of my speakers. How do I get rid of it. Its a real pain to manually turn on and turn off the system in the right sequence. I dont mind this but my wife and kids just turn it off on the remote and I am afraid i am going to blow my lovely legacy audio speakers. Appreciate any help here. Thanks.
 
Last edited:
TLS Guy

TLS Guy

Audioholic Slumlord
I have a Marantz 7704 pre amp and a Monolith power amp. I am using XLR cables to connect the preamp to the power amp. When I manually turn on and turn off the system in the right sequence everything is fine but when I use the 12v trigger to the power amp I am hearing a very loud pop/snap from one of my speakers. How do I get rid of it. Its a real pain to manually turn on and turn off the system in the right sequence. I dont mind this but my wife and kids just turn it off on the remote and I am afraid i am going to blow my lovely legacy audio speakers. Appreciate any help here. Thanks.
What is the sequence that stops the pop? I assume that if you turn on the power amps first and then the preamp there is no pop. Then turning off the power amps first is the sequence of choice I suspect. This is a common problem turning on power amps due to DC off set issues starting up. Yes, this will damage your speakers.

The cure I know for this, is to have relays between the amp and speakers that connect the speakers after a delay. To do this you have to design and build an LM timer circuit. I would just forget the trigger and turn on the units individually.
 
V

Vignesh

Audiophyte
What is the sequence that stops the pop? I assume that if you turn on the power amps first and then the preamp there is no pop. Then turning off the power amps first is the sequence of choice I suspect. This is a common problem turning on power amps due to DC off set issues starting up. Yes, this will damage your speakers.

The cure I know for this, is to have relays between the amp and speakers that connect the speakers after a delay. To do this you have to design and build an LM timer circuit. I would just forget the trigger and turn on the units individually.
The sequence that works properly is for turning on is Preamps first then the power amp and for turning off its the reverse (power amp first, them preamp) Is this what everyone with separates is going through or building a timer circuit like you mentioned. I find it hard it hard to believe. Anyway thanks for your input. Much appreciated.
 
WaynePflughaupt

WaynePflughaupt

Audioholic Field Marshall
Is this what everyone with separates is going through or building a timer circuit like you mentioned. I find it hard it hard to believe.
I’ve been using the vintage Adcom ACE-515 for decades, which accomplishes the on and off power sequencing. You can readily find them used on ebay pretty cheap.

The 515 has two power cords – one heavy-duty that plugs into the wall, and a second “sensing” line that plugs into the switched convenience outlet on the back of my receiver. When the sensing line gets power (when the receiver is turned on), it activates the power sequencing and delays the amp power-on for 10s. When the receiver is turned off, it delays the power-off to the amp for 30s.

Your Marantz doesn’t have convenience outlets, but you could use the 12-volt trigger to switch a power strip, like the one linked below. The Adcom’s sensing line would plug into that, and it would work as I described above.


Regards,
Wayne A. Pflughaupt
 
TLS Guy

TLS Guy

Audioholic Slumlord
The sequence that works properly is for turning on is Preamps first then the power amp and for turning off its the reverse (power amp first, them preamp) Is this what everyone with separates is going through or building a timer circuit like you mentioned. I find it hard it hard to believe. Anyway thanks for your input. Much appreciated.
Power amps that can thump like that should have a delay connecting the speakers. Most power amps do have a turn on thump and contain the relay timer circuit. Pretty much every receiver has it.

That is another reason I like my Quad amps, as they have no turn on or off thumps and so there is no need for relays in the speaker leads.
 
S

sterling shoote

Audioholic General
Power amps that can thump like that should have a delay connecting the speakers. Most power amps do have a turn on thump and contain the relay timer circuit. Pretty much every receiver has it.

That is another reason I like my Quad amps, as they have no turn on or off thumps and so there is no need for relays in the speaker leads.
Seems to me perhaps the trigger is not synced to first turn on pre then power amp in OP's scenario where the equipment is from two different manufacturers? I've been wondering if I replace my Sony Pre-Pro with a modern Marantz model if it will properly sync with my Sony Power Amp?
 
V

Vignesh

Audiophyte
P

PENG

Audioholic Overlord
I have a Marantz 7704 pre amp and a Monolith power amp. I am using XLR cables to connect the preamp to the power amp. When I manually turn on and turn off the system in the right sequence everything is fine but when I use the 12v trigger to the power amp I am hearing a very loud pop/snap from one of my speakers. How do I get rid of it. Its a real pain to manually turn on and turn off the system in the right sequence. I dont mind this but my wife and kids just turn it off on the remote and I am afraid i am going to blow my lovely legacy audio speakers. Appreciate any help here. Thanks.
This is strange, there should be enough delay build in to allow the preamp to settle before the power amp is "on". I have had two Marantz prepro and at least two Denon so far using the trigger with at 4 different power amps and there was never any such thumps.

Is the AV7704 still under warranty? Either way you should contact Marantz and see what they have to say and offer. If they cannot help you resolve it, then some of those recommended hardware may be the way to go, unless you are handy enough to build your own. Until then, follow the On/Off sequence just to play safe.
 
highfigh

highfigh

Audioholic Overlord
I have a Marantz 7704 pre amp and a Monolith power amp. I am using XLR cables to connect the preamp to the power amp. When I manually turn on and turn off the system in the right sequence everything is fine but when I use the 12v trigger to the power amp I am hearing a very loud pop/snap from one of my speakers. How do I get rid of it. Its a real pain to manually turn on and turn off the system in the right sequence. I dont mind this but my wife and kids just turn it off on the remote and I am afraid i am going to blow my lovely legacy audio speakers. Appreciate any help here. Thanks.
The fact that the sound comes from one speaker tells me that the power amp has a problem.
 
P

PENG

Audioholic Overlord
The fact that the sound comes from one speaker tells me that the power amp has a problem.
Good observation! I missed that important point. However, it could be the preamp too, in fact I would say a little more likely.. Easy to verify though, by just swapping interconnects.
 

newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top