USB to 12V trigger input?

[mcb]

I recently purchased a March P452 amplifier which has 12V trigger input. I use an OPPO BDP-105 as the source device but it doesn't have trigger output. I'm wondering if I can use a USB to 3.5mm adaptor instead.

Like this one: https://www.amazon.com/RitZ-MarT-3-5mm-Audio-Charge-Adapter/dp/B0787XDXFV

I think USB is 5V, not 12V, but I understand it will do the job. I'm less clear on electrical connection correctness.

Thanks for any help.

 

[mcb]

To clarify, the USB connection on the OPPO is an input, but shouldn't this still have power?

 

[Wayne A. Pflughaupt]

Voltage question aside, it likely won’t work because an amp’s 12v 3.5 input uses a TS (mono) plug. That one is TRRS.

Regards,
Wayne A. Pflughaupt

 

[mcb]

Voltage question aside, it likely won’t work because an amp’s 12v 3.5 input uses a TS (mono) plug. That one is TRRS.

Your response inspired a little more research. I believe the TS and TRRS are mechanically compatible - they can both plug into the same socket. And I'm not interested in transmitting any sort of signal, just voltage.

From https://lexuscarumors.com/usb-wiring-diagram/

According to Usb Type A Wiring Diagram, there are just four wires used inside the cable. Typically it utilizes black, green, red and white cable colors. Black wire serves as ground, just like in any other device. The red one is for positive wire with DC power of 5 liter. Green and white function as information cable with green indicates negative and white as positive.

I think the author meant 5 volts, not 5 liters...

So if I slice open a USB cable and connect the black wire to the sleeve of a TS 3.5 mm connector and the red to the tip, am I good to go? (maybe test with volt meter first) Or does the polarity even matter? (hum a possible issue?)

Could be a business opportunity for someone!

 

[Wayne A. Pflughaupt]

Sounds like your idea would work, as long as there isn’t a milliamp issue (i.e. the trigger requiring more than the USB has).

Regards,
Wayne A. Pflughaupt

 

[Gyosa1]

I have a Cambridge 851n that doesn’t have a 12v output trigger ....
I needed it to turn on my amp ...

so I made a usb to 3.5mm mono trigger ...

Works perfect !
The 851 USB “input“ ports have power WHEN the unit is turned on ....

Cut the end off a USB cable , stripped the sheath off ....
The green and white are data , the red and black are power , black being ground.
Spliced the usb power wires to a mono 3.5mm jack cable and presto , 851 now has a 12v trigger out !! Snip the green/white wires , wrap rest with electrical tape or whatever to make pretty ...

Turns the amp on and off when the 851 is powered on and off !

It would probably work with anything , TV’s etc , that has a powered USB port ....

Bk

 

[Gyosa1]

 

[Gyosa1]

Just in case anyone else is interested...
Personally , I think this is a potentially great problem solver for some ...
I know it was for me ...
I figured it out after I found the above info , knowing a USB port had power ....
Bk

 

[Gyosa1]

 

[ethanhallbeyer]

this sends 12v signal to amp via the 3.5mm plug when your 851n is turned on? amp triggers on and odd, that is awesome!

i have the same need except i have RME ADI-2 DAC FS, which may draw less powerr when turne on than your 851n? do you think it should still work?

other questions:
1. can i use a 12v trigger y-cable if my amps are monoblocks w/ 12v triggers?

2. would a modified usb cable like this degrade usb signal quality from source to dac if the source device is separate? i use a laptop or pc or ipad as source with usb out to my RME ADI-2 DAC FS dac/dsp/volume control, from there balanced xlr out to monoblock amps. i would imagine i would plug one end of the modified usb cable to the source, other end to the dac (square end), the 3.5mm plug into my monoblock(s).

3. would this be continously supplying a 12v signal to amp’s 12v trigger for as long as your 852n is on?

 

[Ykar]

I recently purchased a March P452 amplifier which has 12V trigger input. I use an OPPO BDP-105 as the source device but it doesn't have trigger output. I'm wondering if I can use a USB to 3.5mm adaptor instead.

Like this one: https://www.amazon.com/RitZ-MarT-3-5mm-Audio-Charge-Adapter/dp/B0787XDXFV

I think USB is 5V, not 12V, but I understand it will do the job. I'm less clear on electrical connection correctness.

Thanks for any help.

This is the way I trigger my NC250MP blocks and that works perfectly (minimum voltage is 3.3V). I used an old USB cable soldered to an old TRS.

 

[Gyosa1]

USB ports ARE typically 5v - that’s the usb standard ....
Most trigger inputs will work with less than 12v ..... usually anywhere from 5-12 v...
There is no standard for trigger inputs from what I gather .

All I know is it works perfectly !

1. can i use a 12v trigger y-cable if my amps are monoblocks w/ 12v triggers?

dunno .... I guess it depends on how much voltage is being split , and how much voltage each amp needs to trigger it.
give it a try. I’d try to find a 3.5mm mono cable Y splitter - if they exist - or make one if not.


2. would a modified usb cable like this degrade usb signal quality from source to dac if the source device is separate? i use a laptop or pc or ipad as source with usb out to my RME ADI-2 DAC FS dac/dsp/volume control, from there balanced xlr out to monoblock amps. i would imagine i would plug one end of the modified usb cable to the source, other end to the dac (square end), the 3.5mm plug into my monoblock(s).

not sure I follow you here .....are you talking about trying to use the same cable to trigger and provide an audio signal ? If so , not sure how you’d do it - sounds doubtful.


3. would this be continously supplying a 12v signal to amp’s 12v trigger for as long as your 852n is on?

yes , as long as the 851 is on the amp stays on.
when the 851 is turned off , the amp turns off.


bk

 

[ethanhallbeyer]

USB ports ARE typically 5v - that’s the usb standard ....
Most trigger inputs will work with less than 12v ..... usually anywhere from 5-12 v...
There is no standard for trigger inputs from what I gather .

All I know is it works perfectly !

1. can i use a 12v trigger y-cable if my amps are monoblocks w/ 12v triggers?

dunno .... I guess it depends on how much voltage is being split , and how much voltage each amp needs to trigger it.
give it a try. I’d try to find a 3.5mm mono cable Y splitter - if they exist - or make one if not.


2. would a modified usb cable like this degrade usb signal quality from source to dac if the source device is separate? i use a laptop or pc or ipad as source with usb out to my RME ADI-2 DAC FS dac/dsp/volume control, from there balanced xlr out to monoblock amps. i would imagine i would plug one end of the modified usb cable to the source, other end to the dac (square end), the 3.5mm plug into my monoblock(s).

not sure I follow you here .....are you talking about trying to use the same cable to trigger and provide an audio signal ? If so , not sure how you’d do it - sounds doubtful.


3. would this be continously supplying a 12v signal to amp’s 12v trigger for as long as your 852n is on?

yes , as long as the 851 is on the amp stays on.
when the 851 is turned off , the amp turns off.


bk

what i meant in #2 is the only usb port on my rme dac is the one that takes the square-ish usb cable plug..it sends the music signal out from my source (ipad pro) to the rme... so t would have to split that cable to add the 12v trigger cable part. if that is even possible. i may explore a remote control sensor that when its power button is pressed would trigger the amps via 12v trigger.

as for #3, i didnt realize that is how 12v triggers work: by a sustained signal. thought it would just send a brief one during power on and off on your 851.

 

[mcb]

Amazon delivered my TS connectors just now. This is what I went with: https://www.amazon.com/gp/product/B07Y8JBMY2
Electrical supply outlets will sell you the connector for much less, but the shipping fees seriously compromise the value proposition.

My first donor USB cable was a frayed Lightning cable from an old iPad. However, when I sliced it open, I saw this:

If I did my research, I would have known that Apple uses the outer shell as ground reference and not a separate ground wire.
https://www.theiphonewiki.com/wiki/Lightning_Connector

So I found an old mini USB cable and sliced open the cable.

I stripped and connected the red and black wires. It works!

 

[McFly]

You guys are saying you took 5V DC from straight from the master devices USB socket and it’s triggering a 12V slave device? Poor little relay I would at least spend a few bucks getting a step-up. But if it works it works more power to ya.

 

[Gyosa1]

why ?

it’s been working flawlessly the last 2 years for me ......

bk

You guys are saying you took 5V DC from straight from the master devices USB socket and it’s triggering a 12V slave device? Poor little relay I would at least spend a few bucks getting a step-up. But if it works it works more power to ya.

 

[catalogguy]

This is a brilliant idea... but if my DAC connects to a Raspberry Pi on the USB input, then I would not think I could use the same USB input for power? Is power possibly available from the coax input?

 

[mcb]

I don't think so. I think you need DC input for the trigger.

You could split open the USB cable and splice the TS connectior inline - so the 12V trigger is in series. If your DAC is powered by the USB, this may have an effect on your sound quality, but if your DAC has its own power supply I think it would be a non issue. Maybe others with more technical insight can comment.

For me, the potential convenience of it working would be worth sacrificing an old USB cable for testing. My kludge has been working perfectly.

 

[catalogguy]

It sounds like you’re using the usb from the dac for the trigger, but for the data connection you use another input?

 

[mcb]

Yes. I have an unmolested USB cable from my NanoPi streaming to my OPPO. The 12V trigger kludge is powered from another USB input on the OPPO.