I've been searching high and low but couldn't find this type of switch. I modified the picture to eliminate the connection at "2":
https://global.discourse-cdn.com/digikey/original/1X/9575ce4e87e3ee1bef34244ec4c7bc2e1f66377c.jpg
The purpose is to avoid relays in a power amp by first switching on the power -which has turn-on thumps- and with a second throw switching on the speakers, keeping the power up of course. I think this is a very elegant solution.
I found these https://www.digikey.be/nl/products/detail/e-switch/PB300DTQ/6126492
but 0,3A @ 28VDC is not suited for power and speaker connections.
Over here is exactly what I'm looking for so perhaps the tube guys can point me to anything useful:
https://groupdiy.com/threads/power-on-off-thumps-and-plops.77677/post-990387
Thanks for any help,
Hugo
https://global.discourse-cdn.com/digikey/original/1X/9575ce4e87e3ee1bef34244ec4c7bc2e1f66377c.jpg
The purpose is to avoid relays in a power amp by first switching on the power -which has turn-on thumps- and with a second throw switching on the speakers, keeping the power up of course. I think this is a very elegant solution.
I found these https://www.digikey.be/nl/products/detail/e-switch/PB300DTQ/6126492
but 0,3A @ 28VDC is not suited for power and speaker connections.
Over here is exactly what I'm looking for so perhaps the tube guys can point me to anything useful:
https://groupdiy.com/threads/power-on-off-thumps-and-plops.77677/post-990387
Thanks for any help,
Hugo
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And what do you think of the idea?
I know purist don't like switching contacts or relays in the signal path, but my old ears won't bother..
There isn't any other way to solve the thumps anyway 🙂
Hugo
I know purist don't like switching contacts or relays in the signal path, but my old ears won't bother..
There isn't any other way to solve the thumps anyway 🙂
Hugo
It will surely work.
As an alternative, there was a guy here 'Chocoholic' I think who designde a small high-power solid state relay.
I have used that as speaker relay and couldn't here a difference.
You can control that with low level signals.
Jan
As an alternative, there was a guy here 'Chocoholic' I think who designde a small high-power solid state relay.
I have used that as speaker relay and couldn't here a difference.
You can control that with low level signals.
Jan
But how do you ensure enough time elapsed between power on and speaker on with a mechanical switch?
Hi Mark,
The switch has 3 position. From 'Off' to 'On' is the first step. It switches the power on.
Then I wait a second (or two) to flip it to the second 'On', witch switches the speaker on. No turn-on thump.
Switching the amp off happens in reverse order.
First the speaker is switched off, second the power. No turn-off thump.
P.S. Point 8 is of no use. 6-2 is power, 3-1 is speaker.
Hugo
The switch has 3 position. From 'Off' to 'On' is the first step. It switches the power on.
Then I wait a second (or two) to flip it to the second 'On', witch switches the speaker on. No turn-on thump.
Switching the amp off happens in reverse order.
First the speaker is switched off, second the power. No turn-off thump.
P.S. Point 8 is of no use. 6-2 is power, 3-1 is speaker.
Hugo
That's not strictly a momentary switch then? Momentary are spring loaded and return to off when released surely?
A DPDT ON-ON-ON toggle switch or a DP3T rotary switch will do for 1 channel.
For 2 channel you need a 4PDT ON-ON-ON toggle switch, or a 3P3T rotary switch.
IMO, switch contacts are no different than relay contacts.
Unless it's switching low voltage power supply, I would not wiring mains voltage together with speaker connection in one switch.
For 2 channel you need a 4PDT ON-ON-ON toggle switch, or a 3P3T rotary switch.
IMO, switch contacts are no different than relay contacts.
Unless it's switching low voltage power supply, I would not wiring mains voltage together with speaker connection in one switch.
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My only concern would be the insulation between the contacts used to switch the power and those used to switch the speaker. The data sheet snippet does show 1500 V dielectric strength but is that across the switch contacts or between the two switches?
Pretty neat idea, though.
Tom
Pretty neat idea, though.
Tom
Correct, wrong semantic 🙂 Actually, it's a Off-On-On switch. I'll ask to change the title.
@Hearinspace : Yes, two mono amps with external PSU. So I'll need two switches.
It will be used for a low current (+/-100mA) unregulated 17V.
@tomchr: I guess this addresses your concern too.
The whole purpose is simplicity and to avoid another circuit with relays. And I kind of like these switches and the process of turning on an amp, vintage style.
I think 'll write a users manual for my heirs. 😊
Thanks for the incentive thoughts and corrections.
Hugo
If you're switching one leg of the AC and one leg of the speaker I would try it before driilling any holes . I don't know but only imagine it possible that 230VAC swinging on one side of an unshielded switch might be audible .
The external PSU will deliver the 17V. That is the voltage the switch will see.
This makes 3 switches: one for the PSU and for each monoblock a power / speaker switch.
230VAC will never reach the amp, if the fuses work, the toroid holds the mains current, the rectifier bridge doens't fail, and all that at ones 🙂
Thanks for voicing your concern.
Hugo
This makes 3 switches: one for the PSU and for each monoblock a power / speaker switch.
230VAC will never reach the amp, if the fuses work, the toroid holds the mains current, the rectifier bridge doens't fail, and all that at ones 🙂
Thanks for voicing your concern.
Hugo