Recent content by LUKE RANDALL

  1. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    I did check that voltage on pin 3...it is at 51 volts. I will check those resistors. Could that resolve the very high voltage I found on pin 1? Thanks.
  2. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    HI- I checked the voltages on these pins. They are all way off. Pin 1 measured 301V. pin 8 measured 34 v. pin 9 measured 24 v. pin 3 was close to the schematic measuring at 51V.......The 6U8 tubes are new....and i was having the problem with the old tubes that were in there too so I don't...
  3. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    Thanks for your response. What should the voltages be on 6U8 pin 1, 8, and 9? I have not checked. I am going on the word of my technician...he says he put a scope on the input stage and as soon as he hit the 6U8 stage it went crazy. Clean prior to that.
  4. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    I am sad to report that the distortion is still hugely present even after reconnecting the 330K resistors. It is very distorted and low levels and then sounds like the tubes are starting to motorboat at about half volume. I checked the plate voltage and it is at 499-500 and I checked grid...
  5. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    Thanks. I balanced the grid voltage but what you are saying is that that is not the goal it is current flow that needs to be equal.. In a perfect world one would think with the same tube installed and the same grid and plate voltage that you would have equal current.
  6. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    Hi Dave- I am wondering if I can add the 10 ohm resistor from cathode to ground or do I need to disconnect ground from the cathode then put the resistor between ground and cathode? There are a lot of wires going to that ground on each tube. I jumped the cut of 330K resistors back on...
  7. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    Thanks Dave. I thought it was Ohm's law.
  8. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    OK- Ok Thanks Dave!., Here is one more basic question: Once I have installed a 10 ohm resistor from the cathode to ground, how do I measure the current? Do i measure the voltage across the resistor and use ohms's law to get the amount of current flow or do I hook up my meter in the current...
  9. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    What purpose do the current monitoring resistors server? I know this is a dumb question.....but how much current am I supposed to see there? Is there an optimum current? Do I then add or subtract resistors at the grid to achieve this current? I understand the bias balance control. I am not...
  10. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    Wow- Thant gives me a lot to think about. I think Primo sounds mentioned putting a resistor in to measure bias voltage. How do I do this again?
  11. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    I see a 1 K resistor from the grid then to the 330K then to pin 5 (cathode) and to ground. I think you might have solved my problem....I am hoping. I will remove the 680K and put the 330K back . Thanks
  12. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    I talked to my technician and he said the voltage was around -40 at the balance pot. I will check it tomorrow on Pin 5 of the power tube and see what's there..
  13. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    What should the bias voltage be on that pin5?
  14. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    Where should the 330K resistors be connected to? Please see the above photo....there is a resistor still on pin 5 ... 680K that connects to two more in parallel then to one side of the bias balance pot. (i think that is what that is.)
  15. LUKE RANDALL

    Scott Stereomaster distortion Type 340 Tuner/Amp

    here is a photo of the resistor cut on pin 5 of the power tube. It looks like a 680k resistor is there under it. I will post a picture of the 6u8 section. I checked the values on the 6u8 pins and they seemed to correlate to tHE sCHEmatic.
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