dcgillespie's Recent Activity

  1. dcgillespie replied to the thread Increase of 299C power.

    Increasing the resistance will in fact get the quiescent voltage in line. However, it does so while adding significantly more heat under...

    Aug 20, 2017 at 6:07 AM
  2. dcgillespie replied to the thread Increase of 299C power.

    Yup -- Like I said -- at least 440 vac, and more if you run at 117 or straight off the line. The transformer on my 208 here is producing...

    Aug 20, 2017 at 12:31 AM
  3. dcgillespie replied to the thread Increase of 299C power.

    It's best to do it through a variac if you have one -- ramp the voltage up, and most importantly, ramp it down. Switching it off...

    Aug 19, 2017 at 10:59 PM
  4. dcgillespie replied to the thread Increase of 299C power.

    Old -- what AC voltage readings are you getting at pins 4 and 6 of the rectifier tube (reading between these pins and ground) of your...

    Aug 19, 2017 at 10:12 PM
  5. dcgillespie replied to the thread Fisher x100c heater circuit.

    Only one heater pin on one of the 12AX7s in the phono and tone control section is grounded, as they are all connected in series to act...

    Aug 19, 2017 at 9:38 PM
  6. dcgillespie replied to the thread Increase of 299C power.

    Old -- Stratospheric voltages are not an uncommon problem with Scott equipment. It's possible that one of their transformer vendors just...

    Aug 19, 2017 at 8:41 PM
  7. dcgillespie replied to the thread Did I score?.

    With the S-265Q output transformer, the unit is no doubt built to the circuit of "The Musicians Amplifier" by Sarser and Sprinkle. You...

    Aug 19, 2017 at 6:28 PM
  8. dcgillespie replied to the thread Scott LK-72 Rehab.

    Dave -- No reason to change the 330K resistors to 220K, as the Grid #1 DC resistance of this design is well within the specification for...

    Aug 19, 2017 at 6:24 PM
  9. dcgillespie replied to the thread A Vintage Restoration of a Vintage Classic: Scott's Original LK-72.

    Search for the thread on the build and I think the performance numbers are in there.

    Aug 18, 2017 at 1:29 AM
  10. dcgillespie replied to the thread A Vintage Restoration of a Vintage Classic: Scott's Original LK-72.

    Patrice -- That's another amp that used a high primary impedance OPT as well (~ 7600Ω), which reduces the power output. But at least...

    Aug 18, 2017 at 12:04 AM
  11. dcgillespie replied to the thread H.H. Scott 130 Preamplifier channel bleed help.

    It's a problem I've seen a number of times in Scott units. Invariably, the answer is better shielding of the components used between the...

    Aug 17, 2017 at 2:15 PM
  12. dcgillespie replied to the thread 202-R Arrived.

    Brass.

    Aug 17, 2017 at 11:40 AM
  13. dcgillespie replied to the thread A Vintage Restoration of a Vintage Classic: Scott's Original LK-72.

    Train -- Other than Mac, virtually none of the vintage units will output rated power with both channels driven across the full audio...

    Aug 17, 2017 at 11:09 AM
  14. dcgillespie replied to the thread A Vintage Restoration of a Vintage Classic: Scott's Original LK-72.

    Thanks Dave. Contrast was really the reason I put the post up. The actual piece of equipment could have been any one of a number of...

    Aug 17, 2017 at 10:14 AM
  15. dcgillespie replied to the thread 202-R Arrived.

    Super job Joe. How you do bring Fishers back with more than both feet in the grave!

    Aug 17, 2017 at 12:42 AM