Removing pops/clicks at power on/off
I ran some tests today to verify the theory that asserting Mute (J4.13 or J4.4) on power up and power off will solve the problem.
It does work to completely remove the power on/off pops and clicks.
This requires keeping the +5V standby power always on for control to make this will work. With this method, the AC mains will remain on and the +5V standby supply will be used to manage the main power on and off behavior. I suspect that some commercial builds use this method with front panel switches. A prior post of mine estimated the quite small cost of leaving this on 24/7.
The next step is to build a prototype with an external +12V trigger input and an optical isolator and a Schmitt trigger inverter IC. Timing information from Hypex data sheets indicate that simple logic with no delays will be fine since Mute is faster acting than turn on/off.
View attachment 56090
I need to do this. The power up and power down pops/transient energy is really bothering me in an otherwise solid build. I have a 3 channel nc502mp+nc500mp build. I have a 12 volt trigger
I did not build the amp. I have basic knowledge, can solder, but I was wondering if you could help break this down to the point where its idiot-proof! I could wire one of these devices together but once you step outside of the main build that I've seen a thousand times, I need some help.
Would you consider this? Thanks.
For reference, I have a ghent 3 channel case with triggers in and out that we're drilled out. I have tried every combination of startup and shutdown and it just doesn't matter, I get pops every time. When I use the trigger, I get a weird buzz on shutdown, but it isn't as loud as the pops. Most of the startup and shutdown noise comes from my center channel(center is on the 500mp. Also, it's possible my preouts help with this. My avr let's me turn off the internal amps, but just for the mains or all 11 channels).
I've got a power conditioner that I got on ebay because it's triggered and powers everything on. High current switched startup delay x2, and regular switched shutdown delay x4. Pops with either of these options on startup and shutdown. Also pops with 12v trigger input, and when just turned on normally. Order of components doesn't matter.
Sorry for the length. Thank you everyone