WOPL 400 Down Under
- Thread starter Timmienator
- Start date
- Joined
- May 24, 2021
- Messages
- 61
Yes Don's DCP installed and functional I presume.
I took a video of what happens but it is too big to be uploaded apparently.
The meter input leads come from the back plane so if the DCP is functional the outputs/speakers will see nothing that is shown on the meters after power is cut. Quiet speakers support my theory I hope!
My guess is that it is the POS and NEG rails discharging at different rates which is causing the issue, if I'm correct is there anything to worry about?
I took a video of what happens but it is too big to be uploaded apparently.
The meter input leads come from the back plane so if the DCP is functional the outputs/speakers will see nothing that is shown on the meters after power is cut. Quiet speakers support my theory I hope!
My guess is that it is the POS and NEG rails discharging at different rates which is causing the issue, if I'm correct is there anything to worry about?
Timmie
That is quite normal for a stock PL400, also known as the turn off thump. Based on your thread postings so far, you still have the stock board in place. It will be more pronounced in the meters if:
That is quite normal for a stock PL400, also known as the turn off thump. Based on your thread postings so far, you still have the stock board in place. It will be more pronounced in the meters if:
- You have the light board jumper in the most sensitive position -20dB
- You have no speakers attached during that turn off sequence, if speakers are attached, you will hear it in the speakers and the meters will move less
Timmie
You just posted that you have Don's board installed. That disconnects the speakers on turn off so the turn off thump has no where to go except the meters. It is the final gasp of the energy in the bulk caps, the control board loses control when the voltage on the caps drops too low.
This is greatly improved on the White Oak Audio board, but you don't have that in place yet.
You should move your meter leads to the output of the DCP. That will eliminate any of this.
You just posted that you have Don's board installed. That disconnects the speakers on turn off so the turn off thump has no where to go except the meters. It is the final gasp of the energy in the bulk caps, the control board loses control when the voltage on the caps drops too low.
This is greatly improved on the White Oak Audio board, but you don't have that in place yet.
You should move your meter leads to the output of the DCP. That will eliminate any of this.
At this point. is a good time to ohm out the resistors note that their are some that will ohm out haft value because their in parallel (I actually ohm out groups of resistor before I soldered them w a cheat sheet I made)
I would check before clipping the ends off but made sure their not touching each other.
I would check before clipping the ends off but made sure their not touching each other.
700 can be destructive UNLESS you know what you are doing. If you have a good technique and don't dwell, otherwise it is high. I say that if you are new to soldering, get a practice board and practice practice practice. Your equipment has a lot to do with it and if you are getting good flow, play around with your settings and get used to what works. Jumping straight into a WOPL is not for a beginner. We've seen a bunch of guys screw up and the job looked like ass.