Mark Levinson N28 - Manual (Page 13)

8
If you wish to vary the input capacitance of the phono option to
obtain the optimal value for a particular cartridge, a capacitor may
also be inserted into the optional load terminals (see "Terminating the
optional load" and "Making the internal adjustments").
Because the inherent input capacitance (all switches off) is in parallel
with the optional load terminals, use the following formula to calculate
the actual capacitor needed.
C = C
R
- C
T
- C
P
C = The capacitor value
C
R
= Recommended capacitance value
C
T
= Tonearm capacitance including leads
C
P
= Preamplifier inherent shunt capacitance
(Low-gain phono option = 100pf; high-gain phono option = 1000pf)
Note: We recommend high-quality polypropylene, polystyrene
or Teflon capacitors; see your Mark Levinson dealer.
1. Make sure all associated equipment is disconnected from the AC
mains, and that the PLS-228 is disconnected from the AC mains.
2. Using a 5/64" Allen key, remove the eight 6-32 flat-head socket-
cap screws securing the Nº28's top cover. Carefully lift the top
cover and remove it.
Internal adjustments:
varying the input
capacitance
3. Adjust the gain switches (using a ballpoint pen or similar
instrument) and install optional loads as desired.
4. Reassemble the Nº28.
Phono gain
(right channel)
Cartridge loading
(right channel)
Line gain
Phono gain
(left channel)
Cartridge loading
(left channel)
Optional load pins
Optional load pins
O
F
F
1 2 O
N OFF
1 2 3 4
Making the internal
adjustments
Nº28, internal adjustments