Ramsey Electronics MX10 - Manual (Page 13)

MX10 Page 13
ready to continue with the rest of the project.
❒ 39. Install R54, a 10K ohm resistor (brown-black-orange).
❒ 40. Install R52, a 10K ohm resistor (brown-black-orange).
❒ 41. Install R82, a 10K ohm resistor (brown-black-orange).
❒ 42. Install R70, a 100K ohm resistor (brown-black-yellow).
❒ 43. Install D6, a 1N4148 type diode. This diode and U4:A form the “real
diode” section of the peak hold circuit. “real diode” means that there is
no .7 volt drop across the diode that would normally occur with just a
diode by itself. This “real diode” allows us to rectify signals all the way
from 0 volts up to a few volts less than the supply voltage; a diode by itself
would only be from .7 volts up, not allowing us to see any low level signals
below .7 volts on the peak hold circuit.
❒ 44. Install R46, a 10K ohm resistor (brown-black-orange).
❒ 45. Install U4, a LF347 type opamp. Make sure and align the notch or dot
associated with pin one with the notch shown in the parts layout diagram.
Also check to be sure all 14 pins are through the board before soldering
the IC in place. This IC is responsible for the peak hold circuits and the
main mixer (summing amplifiers) circuits.
❒ 46. Install R88, a 68K ohm resistor (blue-gray-orange).
❒ 47. Install R48, a 10K ohm resistor (brown-black-orange).
❒ 48. Install R42, a 1K ohm resistor (brown-black-red).
❒ 49. Install R66, a 1M ohm resistor (brown-black-green).
❒ 50. Install R64, a 1M ohm resistor (brown-black-green).
❒ 51. Install R65, a 100K ohm resistor (brown-black-yellow).
❒ 52. Install U6, a LF347 type quad opamp. Make sure and align the dot or
notch with the notch shown in the parts layout diagram. Make sure all 14
pins are through the board before soldering. This IC is responsible for the
RIAA circuits and the split supply ground reference.
❒ 53. Install R4, a 10K ohm resistor (brown-black-orange).
❒ 54. Install R1, a 10K ohm resistor (brown-black-orange).
❒ 55. Install R83, a 1K ohm resistor (brown-black-red).
❒ 56. Install R71, a 100K ohm resistor (brown-black-yellow).
❒ 57. Install R60, a 100K ohm resistor (brown-black-yellow).
❒ 58. Install D19, a 1N4148 type diode (orange glass body with black
stripe). Make sure and install the stripe (cathode) in the same orientation
as shown in the parts layout diagram.