Abbingdon Music Research PH-77 Reference Class - Manual (Page 14)

14
3.4 Loading Options
Different cartridges have different ideal load values.The PH-77 offers two comprehensive sets of 32 different load
values for MC and MM cartridges.
Selecting a Standard PH-77 Load
Please refer to sub-section 4.5 Individual Default Loading on how to use the menu system to select one of the PH-
77’s MC/MM load values.
Setting-up a Non-Standard, Custom Load
It is possible to utilise a custom load for a cartridge: ONLY when using a direct source via the rear panel (R6/R7)
and NOT through multiple sources via the rear panel (R8). This option will meet for example, the requirement of
cartridges that specify unique and highly specific cartridge loads the PH-77 cannot provide as standard or for those
who wish to use a particular brand of resistor to perform the loading.
To setup a non-standard load for your cartridge:
i. With the vinyl source connected to the Direct input/ground post (R7/R5), select ‘Direct’ on Input switch (R3).
ii. Ensure that the load setting is at the nominal value of 47k for an MC cartridge or 70pf for an MM cartridge.
iii. Fit the desired resistor/s to one set of male RCA connectors for the left/right channels.
iv. Connect these left/right male RCA connectors to the respective female Load connectors (R6).
www.amr-audio.co.uk
lists the PH-77’s MC/
MM load values
Note: if using multiple
sources via Normal
inputs 1-3 (R8),
always ensure
Direct Input (R7) and
Load (R6) and the
Ground post (R5/R9)
are all disconnected