I picked up a Pass Labs X1 pre-amplifier and it has a 12 VDC "Amp Turn On" output signal. The manual specifies it handles 50mA max. Has anyone found a way to use this signal to turn on/off the external amplifiers that don't have this feature? I was thinking to insert a relay to close the power switch in the amps when activated. Alternatively, I could avoid modifying the amps and build switched outlets. I have two questions to ask:
- Is doing this a bad idea?
- What relays and/or circuit should I use?
The relays I found either don't provide any current specifications on the DC input at all or their rating is too high (~48mA per relay).
To answer your questions:
- No, it can be done.
- This depends on the power supply circuit of the amplifier. Some amplifiers can be turned on through a switched outlet, while some amplifiers have built-in standby circuits and still need to press the power button on the front panel to activate.
I have a Threshold s/200 and a Sanders Audio Crossover Amp. The latter is pretty much the same as the s/200 as it was designed at CODA by previous Threshold designers. The former lends itself to the switched outlet as it only has a master power switch. The latter can't or it resets the configuration. However it has a dedicated amplifier power switch that does this. I'm more interested in the s/200 as it runs hot while idle, the Sanders doesn't.
As usual, Rod Elliott has it covered:
https://sound-au.com/project156.htm
Relay alone will draw too much current.
That means using a transistor as a switch to switch the relay and a separate supply.
Anything you DIY for mains must be done with due regard to electrical safety.
Ready made unit (12V 33mA):
https://www.audiophonics.fr/en/diy-...v-230v-slave-power-supply-device-p-10661.html
Or you get up and walk to the power switch.
https://sound-au.com/project156.htm
Relay alone will draw too much current.
That means using a transistor as a switch to switch the relay and a separate supply.
Anything you DIY for mains must be done with due regard to electrical safety.
Ready made unit (12V 33mA):
https://www.audiophonics.fr/en/diy-...v-230v-slave-power-supply-device-p-10661.html
Or you get up and walk to the power switch.
Thanks, I'll be digging in to this info. I'm not unfamiliar with working with electricity safely but I appreciate the reminder. 👍
Ready made unit for 120VAC mains:
https://cdn.sparkfun.com/assets/a/5/d/a/f/iot2spec.pdf
https://www.digikey.com/en/products/detail/scs/770069/13152231?
https://cdn.sparkfun.com/assets/a/5/d/a/f/iot2spec.pdf
https://www.digikey.com/en/products/detail/scs/770069/13152231?