Relays: 9 volt versus 5 volt

[Taylor]

I was told by someone that 5 volt relays will be quieter for audio switching than the equivalent 9 volt relay. Can anyone give an opinion on that?

It's not too hard to do a 5 volt regulator, but in a circuit which has nothing else powered by 5 volts, is it worth it to do the regulator and 5 volt relay instead of using the already-available 9v for a 9v relay? Is it a good idea to regulate the relay power anyway, for noise concerns?

[Pablo1234]

I personally don't like regulators in my audio Equipment, mostly use them for Digital Stuff, if your not running battery's use a zener and current regulating resistor to drop it to 5V.

[Processaurus]

I personally don't like regulators in my audio Equipment

Be ready then, to not like anything with a decently quiet power supply built in the last 30 years...

I was told by someone that 5 volt relays will be quieter for audio switching than the equivalent 9 volt relay. Can anyone give an opinion on that?

It's not too hard to do a 5 volt regulator, but in a circuit which has nothing else powered by 5 volts, is it worth it to do the regulator and 5 volt relay instead of using the already-available 9v for a 9v relay? Is it a good idea to regulate the relay power anyway, for noise concerns?

http://www.diystompboxes.com/smfforum/index.php?topic=82010.msg695953#msg695953

2 resistors perform just as well as a 78L05 regulator, in this application, to drop the voltage seen across the coils to 5v.  The switching noise being different between 9v and 5v relays sounds questionable, maybe that person didn't change their circuit to adapt it to the 5v relays?

[Pablo1234]

a zener and power resistor is quieter than a regulator, less components, less space on the board. Only real issue with using zeners is they wast power, but my stuff ain't energy start rated lol

[defaced]

I see no reason why it would make a difference provided good grounding practices are used (keep your switching grounds out of the audio grounds).  A relay has to generate a given magnetic field to move the armature.  If you look at an Omron G5V datasheet for example, turns of wire are adjusted to change resistance/current/voltage.  The armature doesn't change, the coil design does, so I can't see any reason how the magnetic field can change.   I use 24v relays in my amp builds for reduced current requirements which helps driver circuits.  Other amps pull the relay power off of the heaters so they use 5v relays.  I've never noticed a difference. 

As for powering relays, who cares?  Their coil is not in the audio path, and they've got a tolerance as wide as the grand canyon.  They're really pretty primitive devises, but they do their job well. 

[merlinb]

I was told by someone that 5 volt relays will be quieter for audio switching than the equivalent 9 volt relay. Can anyone give an opinion on that?

It makes no difference what the coil voltage is, and it doesn't even need to be regulated.