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  1. Gepetto

    Carver C-500 - valid candidate for White Oak Audio upgrade???

    Hey Glen Transformer saturation will not occur because you load it excessively, its losses will just go up more. Saturation occurs when you do not have enough core area to support the input voltage level at a given frequency. This usually is seen with 50Hz operation at high input line voltage...
  2. Gepetto

    DChristie's PL 2000

    How does it A/B compare on gain to one of your other PL2000s Lee? Same for yours?
  3. Gepetto

    DChristie's PL 2000

    Anybody mess with the resistor values in the gain circuits? You said there were a lot of parts in a bag.
  4. Gepetto

    PL700 Series II Lessons Learned

    What pots did you end up deciding on for the level controls?
  5. Gepetto

    Unfortunately It is Time To Report

    Replaced by a Chinese seller. Selling junk
  6. Gepetto

    Unfortunately It is Time To Report

    Ebay has really watered down any negative info you can leave for someone in the last couple of years. Ebay favors buyers and not sellers which is the height of irony to me.
  7. Gepetto

    Mark's 4000t going through rework

    You would have insisted on oxygen free screws too Perry. Hope Sherry comes along soon, it is a long road back from those leg breaks. They have to support you.
  8. Gepetto

    Mark's 4000t going through rework

    Nice work Perry, Purdy as they say. How's Sherry coming along? Healed yet?
  9. Gepetto

    Need help with a new tape echo unit

    Can I ask what rights you acquired if not the documentation on how to build the unit?
  10. Gepetto

    Adcom GFA-555 Thread

    The other 3 heatsinks look nice and black but the one you are working on looks purple. Maybe the photo does this but the patterns under the transistors look black.
  11. Gepetto

    Carver C1 going through rework

    You have proven to yourself there is no bump noise in the headphones which is driven by this same circuit, the simplest solution is to remove the two 2N5458 JFETs
  12. Gepetto

    Oscilloscopes - Questions, Comments and WTF?

    It will bring you back next year then Lee...glad you had some time off to have some fun.
  13. Gepetto

    Oscilloscopes - Questions, Comments and WTF?

    Like reel in that big fish :-) Thought you went fishing Lee?
  14. Gepetto

    Carver C1 going through rework

    You need to back to back 2 MOSFET devices in an application like this which is why it is complicated. Pictures show what you have to do. Assembled to hopefully show what you have to do. An 1/8W resistor would have been better but could not readily find one.
  15. Gepetto

    Carver C1 going through rework

    yes but it is complicated...
  16. Gepetto

    Carver C1 going through rework

    JFETs typically don't have very low channel "ON" resistance. The reason you still hear music playing while muting is for the above reason. It attenuates but does not really mute it altogether. I think the PL manual tells you this.
  17. Gepetto

    VIZ SINE/SQUARE WAVE AUDIO GENERATOR #WA-504B/44D

    Yup a favorite of mine...
  18. Gepetto

    Carver C1 going through rework

    Note: N channel enhancement mode MOSFETs probably only existed in the lab in the days this preamp was created. JFETs were it in those days.
  19. Gepetto

    Carver C1 going through rework

    Yeah 2 thoughts: The positive bias to the JFET gate is way positive (as in +10V+) during the time you are seeing the 33 and 23 mV and then switches way negative when you see it go back to the level before power on. It could be leakage from the junction FET gate into the drain terminal. This...
  20. Gepetto

    Carver C1 going through rework

    0.1uF may make the transition too slow. Probably should start with 0.01uF instead of 0.1uF. If it has an effect, some experimentation may be needed to optimize it.
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