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  1. mlucitt

    PL2000 preamp square wave ringing.

    I like Rod Elliott's projects. I have built several including an stand alone Headphone Amplifier - P113. https://sound-au.com/project113.htm I used the best OPAMP I could find at the time, a Texas Instruments LME49860. It does sound good. I get 250mW output with the 600 Ohm Headphones.
  2. mlucitt

    PL3000 preamp Recap Mouser parts list.

    And that very nice Volume control!
  3. mlucitt

    PL2000 preamp square wave ringing.

    Marco, Thank you for that explanation. The PL2000 does not have any output transistors. The Left and Right audio output comes directly from a Quad OPAMP (Z3). This was an RC4136 (14 pin DIP), now an SMD pair of Texas Instruments OPA2134 using a 060601 Brown Dog Adapter in a new gold-plated DIP...
  4. mlucitt

    PL2000 preamp square wave ringing.

    Using Tape 1 or Tape 2 without an external headphone amp does not give me volume control. If I intercept the "Front" Left and Right signals before they get to the RCA Jacks on the back and route them to a Panel-mount Switched Stereo Headphone Jack and then back to the RCA Jacks on the back, I...
  5. mlucitt

    PL2000 preamp square wave ringing.

    Let me ask the question a different way. If you decided to add a Headphone Jack to your PL2000 Preamplifier, how would you do that? Clearly, you would want a clean cut-off of the Output Jacks so that both the rear Outputs and the Headphone Jack were not active at the same time. I would probably...
  6. mlucitt

    PL2000 preamp square wave ringing.

    George, have you ever considered installing a headphone jack in your PL2000? I think these preamplifiers could use a headphone jack... if done correctly.
  7. mlucitt

    Marantz sr320 smokes when treble knob 100%

    "the wiper to ground sweep looks like." Sorry, I get carried away. With the amplifier off, set your meter to cover the value of the Treble potentiometer in Ohms. So for a 100K potentiometer, set your meter to 100K Ohms. Or, if your meter is auto-ranging, it will do this automatically...
  8. mlucitt

    Marantz sr320 smokes when treble knob 100%

    Could be a bad pot, sending ground to the circuit. If someone turned the pot past the stops, it could be shorting to the case. Pots are pretty easy to check and change out. I would be curious what the wiper to ground sweep looks like.
  9. mlucitt

    Original light bulbs PL400

    1784 Incandescent Lamps https://normanlamps.com/1784.html
  10. mlucitt

    Butt Whuppin by PL 3300

    I would initially suspect noise from a open/broken trace on the PCB. You could try re-flowing the solder runs of the suspect channel in the area of concern and see if that helps. No parts expended in that exercise, and even if it does not cure the problem, it may prevent other problems in the...
  11. mlucitt

    I got an axe to grind

    Who is Kelly and how do we know he "Works"?
  12. mlucitt

    Original light bulbs PL400

    Those 6.3V bulbs should work. You need 8 bulbs to replace all the original bulbs. Or, you could order a new LED Meter Light Board from White Oak Audio in "Warm White" to match the original incandescent bulb color. Then you will not have a heat problem inside your meters and never worry about...
  13. mlucitt

    Phase Linear 400 bias, advice

    It could be the Bias Adjustment Potentiometer, or several other components on that 50 year old board. It is not advisable to run the amplifier with incorrect bias voltage. The sound will not be affected until it is; the bias is controlling the DC voltage supplied to the Output Transistors, it...
  14. mlucitt

    Looking for phase linear 400 VU meter analogue

    Translation: I am looking for a 400 phase linear VOLUME METER to buy as mine is broken, if you have one for sale let me know thank you
  15. mlucitt

    I Need a Part

    Don, I received them yesterday and installed one today. They are an exact fit (We Have A Winner!). Thank you for searching your parts bin. I you need something from me - it is yours. Sincerely, Mark
  16. mlucitt

    PL 700 version

    RCA 410 Driver Transistors are the consensus here for ruggedness and stability in the Phase Linear Power Amplifier driver position. They are slow, so oscillation is not an issue. The role of the RCA 410 is to set up the bias and drive parameters for the Output Transistors that actually do the...
  17. mlucitt

    Variacs N Stuff

    Well, it could be worse. You could also be addicted to Harley's and Bourbon... nevermind.
  18. mlucitt

    PL 400 series 1

    Retirement is looming later this year. No doubt that will free up some time to catch up. Ha! When you retire, you are working for a new boss, and that guy is a pain in the ass.
  19. mlucitt

    Looking for phase linear 400 VU meter analogue

    Est il à vendre = Is it for sale.
  20. mlucitt

    I Need a Part

    Thanks 007, The ebay post did not give any dimensions or the hole spacing (I need 1 1/8"), so I went ahead and ordered one for $20.00. I should know in a few days. I don't think the PL700 Kulka original AC Receptacle was UL listed, but that is an added bonus.
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