I have a Behringer nu6000dsp that gives a hellacious power-off thump when switched off by my smart power strip.
I want to use a relay at the speaker outputs that will open before the power is removed, which I can achieve with the delayed output on a surge protector I have.
I've perused many threads on relays and it sounds like mechanical ones are problematic because I'll never be switching with a load to keep the contacts cleans.
The possible issue with a SS relay is linearity at low levels.
I'm thinking it's probably not an issue with subwoofer frequencies but wanted to check with the more knowledgeable.
Would this one be suitable?
Solid State Relay 25A | RSS Solid State | Solid State Relays | Relays & Timers | USA
Key Features
Current ratings up to 90A at 660VAC
AC (90-280V) or DC (4-32V) input
Input current regulated 10mA
Photo isolation of input and output (up to 4000V)
Zero voltage turn on
Dual SCR output with built-in snubber
Optional fingersafe cover
Worldwide approvals: UL
C-UL
TUV
CE
LED status indicator standard
Updated pressure plate for easier installation of wires
New housing design keeps wires from twisting and breaking
Dual SCR output with epoxy free design
I want to use a relay at the speaker outputs that will open before the power is removed, which I can achieve with the delayed output on a surge protector I have.
I've perused many threads on relays and it sounds like mechanical ones are problematic because I'll never be switching with a load to keep the contacts cleans.
The possible issue with a SS relay is linearity at low levels.
I'm thinking it's probably not an issue with subwoofer frequencies but wanted to check with the more knowledgeable.
Would this one be suitable?
Solid State Relay 25A | RSS Solid State | Solid State Relays | Relays & Timers | USA
Key Features
Current ratings up to 90A at 660VAC
AC (90-280V) or DC (4-32V) input
Input current regulated 10mA
Photo isolation of input and output (up to 4000V)
Zero voltage turn on
Dual SCR output with built-in snubber
Optional fingersafe cover
Worldwide approvals: UL
C-UL
TUV
CE
LED status indicator standard
Updated pressure plate for easier installation of wires
New housing design keeps wires from twisting and breaking
Dual SCR output with epoxy free design
If you turn it off with the power switch on the amp, does it still thump?
COncerning switching with a load to clean contacts? Unless you switch it on and off while amplifying, unless I miss something, load won't matter. At idle, no current flows through the relay contacts.
Relays are made with "overmake", which we call "scrub". The contacts come together, and continue to close even after first contact. That means one blade pushes the other causing the contacts to rub. They clean themselves.
Try this, hold your arms in front of you, pointing straight up. A few inches apart. Now hold one arm steady and bring the other over so your palms meet - first contact. Now continue to press the moving arm at the other. Notice how one hand slides down the other some. That demonstrates scrub.
Point being a zillion amps have used relays in the speaker lines and problems are not chronic. I'd try one. The SS relay runs your audio through a couple of SCRs, which in my mind would not be optimal.
Just my opinion.
COncerning switching with a load to clean contacts? Unless you switch it on and off while amplifying, unless I miss something, load won't matter. At idle, no current flows through the relay contacts.
Relays are made with "overmake", which we call "scrub". The contacts come together, and continue to close even after first contact. That means one blade pushes the other causing the contacts to rub. They clean themselves.
Try this, hold your arms in front of you, pointing straight up. A few inches apart. Now hold one arm steady and bring the other over so your palms meet - first contact. Now continue to press the moving arm at the other. Notice how one hand slides down the other some. That demonstrates scrub.
Point being a zillion amps have used relays in the speaker lines and problems are not chronic. I'd try one. The SS relay runs your audio through a couple of SCRs, which in my mind would not be optimal.
Just my opinion.
No, it doesn't happen if the front panel switched is used, but I have to crouch down and open a rack door to access it.
I've read other threads and learned that the mechanical relays need to be switched under load (often the specs include a minimum switched current) to clean the contacts.
Plus, I have to remember to do it; the amp has run days at a time when I've forgotten, unnecessarily consuming 70W or so and adding dust load to the fan filters.
Yes, many amps have speaker relays but I believe that's limited to an order of magnitude less power.
I've read other threads and learned that the mechanical relays need to be switched under load (often the specs include a minimum switched current) to clean the contacts.
Plus, I have to remember to do it; the amp has run days at a time when I've forgotten, unnecessarily consuming 70W or so and adding dust load to the fan filters.
Yes, many amps have speaker relays but I believe that's limited to an order of magnitude less power.
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I've done that and there are many reasons for not going that route:
1) It's a pain to get my amp out of the rack
2) I hate working on electronics
3) When I do I often have "oops" moments and damage things
4) I don't want to invest time and money into an amp of questionable reliability; a previous one I had failed
1) It's a pain to get my amp out of the rack
2) I hate working on electronics
3) When I do I often have "oops" moments and damage things
4) I don't want to invest time and money into an amp of questionable reliability; a previous one I had failed
Perhaps then aim for a relay with parallel contacts (eg. 10A 250VAC AC1 rated). Just the on/off use of the relay will wipe the contacts, and if you purposefully have finished any music playing (and don't start with music playing) then the contact opening (and closing) has negligible current to switch. Just add a note in your calendar to swap the relay for a new one in a decade or so.
> Just the on/off use of the relay will wipe the contacts
As I already said
I believe the issue is that mechanical wiping isn't sufficient, it takes some arcing to blast away the oxidation/contamination.
As I already said
I believe the issue is that mechanical wiping isn't sufficient, it takes some arcing to blast away the oxidation/contamination.
I don't subscribe to that form of degradation in general.
If you live beside the sea, or have local contamination issues, then you may well be experiencing that with other equipment failures at your place?
Reading other threads does not make them a good guide unless you have referenced them to the actual application and type/model of relay you are aiming for. I would suggest linking to them to gauge how valid they are to this use.
If you live beside the sea, or have local contamination issues, then you may well be experiencing that with other equipment failures at your place?
Reading other threads does not make them a good guide unless you have referenced them to the actual application and type/model of relay you are aiming for. I would suggest linking to them to gauge how valid they are to this use.
I'd really like to help, but am having a hard time processing. You don't like working on electronics, yet want to build relay circuits or MOSFET circuits to adapt the amp.
SInce it only does this on a power strip. but not on its own power switch, have you tried different power strips? Perhaps better quality filtered strips?
A relay is really just a switch, but it is not activated by fingers. Switch contacts are subject to all things that relay contacts are. I used to work on relay control systems, and carried special tools like burnishers to service relay contacts. Arcing never was a plus, it pits contact surfaces, leading to more sparking and more pitting, etc. Entirely possible the switch on your outlet strip is arcing badly and making the noise
SInce it only does this on a power strip. but not on its own power switch, have you tried different power strips? Perhaps better quality filtered strips?
A relay is really just a switch, but it is not activated by fingers. Switch contacts are subject to all things that relay contacts are. I used to work on relay control systems, and carried special tools like burnishers to service relay contacts. Arcing never was a plus, it pits contact surfaces, leading to more sparking and more pitting, etc. Entirely possible the switch on your outlet strip is arcing badly and making the noise
Then the answer must be to put your relay (solid state or not) in series with the power switch.
> You don't like working on electronics, yet want to build relay circuits or MOSFET circuits to adapt the amp.
Wiring an external relay with easily accessible terminals into the speaker wire path is not a big deal.
Opening up an amp and dealing with a crowded PCB and wiring that I don't understand, and possibly damaging it, is.
> SInce it only does this on a power strip. but not on its own power switch, have you tried different power strips?
Anything that removes power at the power cord will cause the thump.
Wiring an external relay with easily accessible terminals into the speaker wire path is not a big deal.
Opening up an amp and dealing with a crowded PCB and wiring that I don't understand, and possibly damaging it, is.
> SInce it only does this on a power strip. but not on its own power switch, have you tried different power strips?
Anything that removes power at the power cord will cause the thump.
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You may always add a suitably rated finger activated switch cutting one ofn the speaker wires.
Turn on procedure:
Flip power switch ON
Count to 10 and flip Speaker switch ON
Turn off procedure:
Flip Speaker switch OFF
Count to 10 and flip power switch OFF
Works every time.
Zero turn ON/OFF thump, pop,click, etc.
Works with ANY amplifier. (we are talking SS of course)
Turn on procedure:
Flip power switch ON
Count to 10 and flip Speaker switch ON
Turn off procedure:
Flip Speaker switch OFF
Count to 10 and flip power switch OFF
Works every time.
Zero turn ON/OFF thump, pop,click, etc.
Works with ANY amplifier. (we are talking SS of course)
Yes, I thought of that, but that's kind of klutzy and no doubt I'll forget to turn it off sometimes.
It's actually easier than you say; there's no power-on thump and no waiting required at powerdown, since the speakers need to be disconnected first.
I might end up doing that, but I'd much prefer a completely automated solution.
It's actually easier than you say; there's no power-on thump and no waiting required at powerdown, since the speakers need to be disconnected first.
I might end up doing that, but I'd much prefer a completely automated solution.
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I've talked with a couple of suppliers of audio grade SS relays and it turns out to be a tougher and more expensive nut to crack than I anticipated because of the high voltage/current requirements.
For the moment I'm going just try the 25A DP Omron relay I already have, and see how long that goes before having contact trouble because of the lack of cleaning from no-load switching, if that actually even happens.
For the moment I'm going just try the 25A DP Omron relay I already have, and see how long that goes before having contact trouble because of the lack of cleaning from no-load switching, if that actually even happens.
So what? Speakers will thump that time ... doubt they will *die*.
Every now and then I forget to take my blood sugar and pressure pills ... still here
Simply take next at appointed time and everything is fine.
Not "easier", but exactly what I suggest.
While if you want automation:
Power-on thump "logic" is easy, since you have to wait a few seconds *after* power is applied (by your switched power strip), easy peasy; problem is power-off, your system must *guess* your intentions and disconnect speakers on its own *before* you do it.
How will it "know"?
Only scientific paper about precognition I know is the one which got Dr. Isaac Asimov his Dr. in Biochemistry degree :"The Endochronic Properties of resublimated Thiotimoline", the first product known to Science which dissolves in water 10 seconds *before* water is added.
The Endochronic Properties of Resublimated Thiotimoline
Here´s the full Scientific Paper in all its glory:
https://mrl.nyu.edu/~perlin/Thiotimoline.pdf
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