Hi,
PSU finished, and I may finish the Pearl 3 this week too, will see.
It is now a CRCRCRCRC 🤷♂️
PSU finished, and I may finish the Pearl 3 this week too, will see.
It is now a CRCRCRCRC 🤷♂️
Finally, up and running 
Now I just have to integrate it properly into the system.
Now I just have to integrate it properly into the system.
That is a great looking build Istvan!
If you want to get the last % of sound quality out of your P3 you need to switch to blue or cyan LEDs on the front plate 🤣
If you want to get the last % of sound quality out of your P3 you need to switch to blue or cyan LEDs on the front plate 🤣
Have finally got round to the testing stage after a few issues with the PSU. Supply voltage is +/- 17.5vdc. I have a couple of issues - the red LED on one channel is flashing. I have tested the voltage across R27 and this is measuring 2.43v so I'm guessin I need to change the 220R here for 4-500R? Does that sound right and any ideas on the flashing LED. I will check the contacts on that board... The LEds at D3 are not on either but there's -17 vdc at the cathode pad.
Last edited:
Remember, that the 2,43 volt increases slightly, when you increase R27. I would start with 680ohm.
I also (once) had the "flashing LED" (once), which I can´t really explain. Turned out, that I had switched the blue and the green wire on the cartridge,
which results in more or less open circuit in on both channels. Could be "motorboating" due to excessive hum???
I also (once) had the "flashing LED" (once), which I can´t really explain. Turned out, that I had switched the blue and the green wire on the cartridge,
which results in more or less open circuit in on both channels. Could be "motorboating" due to excessive hum???
Have found a couple of 560R resistors and replaced R27 with these and am now getting 2.9v which I think is within range? The red LED is still blinking and then going off...
As we go deeper and deeper in the power supply rabbit hole for our Pearl3 a group buy in the Vendor's Bazar could be very interesting I think. It is the improved version of the Silent Switcher developed by Jan Didden. It allows to stay away from the power grid with very high quality +-15 volt power. In the first round of this GB our friends Mark Johnson and Itsallinmyhead joined to try this with their Pearl3. I noticed this GB too late.... The second GB moves (too) slow and it might not reach the minimum of 100 units. And that would really be a pity, especially for me, myself and I. I really would like to have a couple of those boards. And maybe you would too. So have a look🙂
Update - I now have the green LEDs at D3 on (had the cathod/anode mixed up). The Red LED at D1 on 1 board comes on, flashes and goes off. Voltage on the board that works has -0.92 at R25 and R36 but on the board with the LED not working R25 is -3.8vdc and R36 is 0vdc. Any ideas?