Can someone explain how the output is grounded and what is grounded? How would this be wired up? I'm not getting how the output shorted doesn't fry the amp output.
Is it sending the speaker positive to ground? I looked at 3 other circuits and articles to make sense of it. One of the circuits in the store looks like it disconnects the + and - outputs entirely, but seems like people don't like the signal going through the relay. That correct?
Th protection circuit found in the diy store. https://diyaudiostore.com/products/nelsons-psu-filter
Is it sending the speaker positive to ground? I looked at 3 other circuits and articles to make sense of it. One of the circuits in the store looks like it disconnects the + and - outputs entirely, but seems like people don't like the signal going through the relay. That correct?
Th protection circuit found in the diy store. https://diyaudiostore.com/products/nelsons-psu-filter
The link to the store you provided is not for a speaker protection circuit. It is (as it is titled) a PSU filter with a little "anti-thump" magic for turn on thump reduction.
Correct. I'm confused about how the thump protection works and how it's wired. I also checked the n-ch sony vfet article where the store circuit is derived. Looks like the positive of the output shunts to the turn-on thump circuit, but is also connected to the speaker output. Where does the break take place to prevent the thump?
speaker output, capacitor coupled, is shorted to gnd for short period after power up, to ensure direct path for capacitor charge
idea is that is better to charge cap through relay contacts, avoiding to do the same through speaker voice coil
simple as that
idea is that is better to charge cap through relay contacts, avoiding to do the same through speaker voice coil
simple as that
Sorry for the delay. ZM summed it up VERY well, per usual.
Mainly, I didn't want anyone to think this was a "DC detect" type of speaker protection board. 🙂
One thing that I'm sure is apparent now is that the connection to the board may vary based on how the amp is designed. There are a few common Papa amps that have the output signal at the "negative" binding post. The key is that regardless of which binding post is used, that the "output signal wire" is connected to the filter / anti-thump board vs 'audio ground'. I know that you know this, but ... this is more for anyone reading this after. You had also asked for a some wiring examples. Below are two for something fun. 😉 Apologies if the color choices are not exceptional for web viewing.
If you're considering using one, another two quick tips...
If Q1 and Q2 somehow find themselves in the incorrect positions... it just won't work.
Note the pinout for Q1 and Q2 - substitutions are commonly available, but ... they may not be a "BCE" pinout.
Ask me how I know both of these things...
Edited to correct pinout for Q1 / Q2 - SEE... even I type it in the more common (to me) configuration.
Mainly, I didn't want anyone to think this was a "DC detect" type of speaker protection board. 🙂
One thing that I'm sure is apparent now is that the connection to the board may vary based on how the amp is designed. There are a few common Papa amps that have the output signal at the "negative" binding post. The key is that regardless of which binding post is used, that the "output signal wire" is connected to the filter / anti-thump board vs 'audio ground'. I know that you know this, but ... this is more for anyone reading this after. You had also asked for a some wiring examples. Below are two for something fun. 😉 Apologies if the color choices are not exceptional for web viewing.
If you're considering using one, another two quick tips...
If Q1 and Q2 somehow find themselves in the incorrect positions... it just won't work.
Note the pinout for Q1 and Q2 - substitutions are commonly available, but ... they may not be a "BCE" pinout.
Ask me how I know both of these things...
Edited to correct pinout for Q1 / Q2 - SEE... even I type it in the more common (to me) configuration.