ADDITIONAL INFORMATION
RACK MOUNT END CAP INSTALLATION
Every
Remove all power and signal connections from the DH-
110.On a protected surface such as a towel, remove the two cover screws on each side of the bottom, and slide the cover back. Remove the screws in each corner of the front panel. Exchange the end
PHONO CARTRIDGE CAPACITOR LOADING
The cartridge manufacturer usually specifies in their instructions the optimum ‘load’ or termination for the car- tridge. The needed capacitance is expressed in picofarads (pF). The
The total capacitive load is the sum of three numbers: Turntable cable capacitance (from its manufacturer)
+Preamp input capacitance
+Compensation capacitor (value you desire)
= The specified load (from the cartridge manufacturer)
You need to know the cable capacitance, from either the turntable maker, or the cable supplier, if they are separate. Unfortunately, this is not always readily available, and it can vary widely, but lower capacitance cables invariably are more expensive. If you must guess, use 60pF per foot. If your turntable accepts
As an example: Recommended cartridge load= 320 pF The turntable has a three foot cable, and
they say it is 60pF/foot. Subtract 3 X 60 =
If you require new capacitors, we suggest that you purchase, if possible, either polypropylene or polystyrene types. These premium grades have been selected for all critical circuits in the
Some fastidious users prefer to solder the compensation capacitors in place once a final value has been determined, to preclude any
PHONO CARTRIDGE RESISTIVE LOADING
As supplied, the phono load resistance of the
The input resistance is determined by the parallel com- bination of Rl (101) and R2 (201), each of which is 93.1K ohms (white, orange, brown, red). A different value of Rl
(101)will change the desired load to the value RT in accor- dance with the formula:
Rl =
1 - 93.1/RT
To simplify, the following standard 1% values of Rl will provide desired loads RT as shown (all in Kohms):
Rl Value Kohms | Desired Load Kohms |
11.3 | 10 |
17.8 | 15 |
24.9 | 2 0 |
34.8 | 2 5 |
44.2 | 3 0 |
56 .2 | 3 5 |
Metal film type resistors are recommended for lowest noise.
So far we still need | 140 pF | ||
Subtract the | = - 3 0 | ||
Compensation | capacitor | required | =110 pF |
This is close enough to | the 120pF | supplied that | Phono 1 can |
be used without change.
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