DChristie's PL 2000

An attempt to minimizing popping when attaching your interconnect cables would be a guess.

I would have put them all the way to the right in the schematic, not where they are now. In other words, on the negative side of C49 and C50
 
Those dangling capacitors have no method of discharging themselves other than leakage.
 
The power suppl filtering caps are 1,000 uf, factory calls for 470, is that where I'm picking up the additional voltage? I also have 16 volts AC on the secondaries...
 
laatsch55 said:
That answers that...
Click to expand...

Try putting a 100 ohm 1/2 or 1W resistor in series with the transformer center tap connection to the PC board. Guessing at the value based on the Ic of the op amps. It may need to go higher than that.
 
Lee, I've had good luck with the +/- 12VDC or the +/- 15vdc power supply modules I had built up for the Carver/PL Preamps. Maybe something you want to try. I haven't looked at the Power supply for the unit you are working on. It's got the built in regulators on the boards I built with heat sinks.
 
I noticed that some of the older units had Service Bulletins changing the transformers to 12 volt and changing some opamps and mods to the power supply to work with the new transformers so check all the Service manuals for the unit to see if anything has been done like that. I just had a Pre in that had SOME of the mods done, and some NOT done.
 
Joe I ran the 100 ohmers in series with the 12 volt windings , not the center tap..
 
Lee, the voltages you measured were with no load (no IC's). I would try a quick voltage measurement with the IC's installed to load the power supply a little bit. The voltage will probably come down a bit.
 
WOPL Sniffer said:
Lee, I've had good luck with the +/- 12VDC or the +/- 15vdc power supply modules I had built up for the Carver/PL Preamps. Maybe something you want to try. I haven't looked at the Power supply for the unit you are working on. It's got the built in regulators on the boards I built with heat sinks.
Click to expand...

Thanks Perry..we'll see how it goes here...
 
mlucitt said:
Lee, the voltages you measured were with no load (no IC's). I would try a quick voltage measurement with the IC's installed to load the power supply a little bit. The voltage will probably come down a bit.
Click to expand...

Yeah, I figured it would too, getting the unloaded voltage to less than 18 was a must..
 
laatsch55 said:
Joe I ran the 100 ohmers in series with the 12 volt windings , not the center tap..
Click to expand...
The center tap is just the easiest Lee, either works. When you put them in the 12V legs, you have to double the value (200) to get the result I was looking for in the center tap with 100.
 
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