Relay or switch mains

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Peavey uses a TO3 package triac on the main hot with the heat sink screwed to the case. Legs are .250" spade pointed in. Front panel switch is light duty. Jameco.com sells the triacs in that case but they don't stock in Aust. Peavey might stock in Aust., one amp using it is the PV1.3k. It is not on the schematic so I don't have a part number. Don't forget an EMI snubber on the gate and MOS transient supressor clamps on the main line. .
 
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sorry if i seem a bit dim here but this knowledge also applies in another part of my life,
I assumed a Triac is on or off and not switching each cycle.I also assumed a relay would be good for 1000's of switches? As i hope I imply,I don't know and it would helpful with a non audio applicatition,a packaging machine that needs to switch "silently"
Thanks
 
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Thanks for all the feedback there is still a lot to consider. It seems that maybe noise is not going to be a issue if I lay out properly. If I do run ac to the front panel it will pass one of the large smoothing caps most likely quite closely. Perhaps shielding is an option.
Cheers
 
Peavey triggers the triac with mains AC limited by a resistor and diode through a low cost switch. You only get the hard edge from a triac when it turns on, a triac turn off at ~ two volts AC. So the Power up silence circuit (a J174 jfet with an RC delay) cuts any noise at turn on until the DC power supplies are at full voltage. A relay or hard contact switch can also produce a large sharp voltage edge at turn off.
The triac is in the AC part of the amp, away from the preamp boards. There is a steel divider in the case like a PAS2 preamp between AC and sound.
 
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Even Nelson Pass used a triac in the A75 PSU.

Please add that Papa included a snubber across the triac, plus C1/C3, to help suppress/shorten the transients.
Could have been Mr Thagard's wrong doing (couple of years later he did the A100 with stacked BJT/MOSFET output stages for Audio magazine single-handed, with a few pointers from Mr P)
Back in the late '80s and early '90s everyone was into triacs, me included, remote switching monaurals on/off with the preamp signal and a timer was comfortable.
Not very Audio-Pile nowadays, other more elegant ways.
 
Still noisy compaed to other soilutions, I cannot remember when I last did a board with a triac, possibly 15 years ago, look at dimmer switches, yes they are a bit better these days than the RF transmitters they use to be, but why add anything that could add noise, when everywhere else we try to reduce it.
 
Hi,
What about using the MOC3061. This will power up the amplifier clean since it is start at zero crossing of the AC. Attached it is the technical data. Also you can use a zero crossing relay Omron G3NE-220T-US. I found it no too long ago I am planning to using it in my new design.
 

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