I cannot remember the smallest required voltages for the cards on the 52XX- 5235. Were they 63VDC and above for the capacitors. I am trying to make up the ultra high frequency cards for the 4350's the 9Khz/18db. The 4355's 10Khz are listed and not to much of a problem finding components. Nothing is stated for the 9Khz/18db for the 4350's on caps or resistors. The values I am coming up with are not being found. I am going to quad amp a pair of 4350's and 4355's. Thank you for your responses