ASR Audio Systems Friedrich Schaefer, D- 35 745 Herborn +49 (27 72) 42 905
(DIP switch = „No.“) (47 k when all Dips are OFF )
15K 10K 2K2 1K 470 360 220 100 94 47 22 15 12 Value
1 -- -- -- -- -- -- -- -- -- -- on on on 22
2 -- -- -- -- -- -- -- -- -- on -- on on 47
3 -- -- -- -- -- -- -- on on -- -- -- on 100
4 -- -- -- -- -- -- on -- on -- -- -- on 220
5 -- -- -- -- on on -- -- -- -- -- -- on 475
6 -- -- -- on -- on -- -- -- -- -- -- on 1K
7 -- -- on -- -- -- -- -- -- -- -- -- on 2K2
8 -- on -- -- -- -- -- -- -- -- -- -- on 10K
9 on -- -- -- -- -- -- -- -- -- -- -- on 22K
By using
combinations
of Dip switches you can get additionally values for the resistance.
Formula for the Calculation : 1/R total = 1/R1+ 1/R2+ 1/R3......
Example: 100 and 221 Ohm combined (47 k is fix): 1/Rt=1/100+1/221+1/47000 =1/0,015 Rt=69
3.2
Adjusting the input capacity
The input capacity can be adjusted on DIP switch No. 10: position „Off“ = 100 pF, „On“ = 320pF.
You can easily determine the value for your cartridge by using the cartridge manufacturer’s
recommended value and subtract the capacity of the phono cable you are going to use –
the result is the value you have to adjust in your ASR Mini Basis.
3.
3
Adjusting the gain
The gain can easily be adjusted on the 6 fold DIP switches „Gain Adjust“. The switches can be
combined to get higher gain. The minimal gain of +30 dB is obtained with all Dip switches in OFF,
the Maximum gain of +72 dB is obtained by putting all DIP switches to „ON“.
To know the adjusted gain please add the following values to 30 dB :
switch No. „ON
“ none 6
5 4 3
2 1 All 1-6
Gain
0dB +6dB +12dB +18dB +24dB +30dB +36dB +42dB
Please set the DIP switches exactly the same for the right and the left channel (only exception from
this rule: your cartridge has different output from the right and left channel).
!! The gain should be set as low as necessary to get lowest possible noise !!
3.4
Settings for common cartridges
Input Resistance
Gain
cartridge type
(switch no.)
(switch no.)
1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- on MM,MC High Output
-- -- -- -- on -- -- -- -- -- -- -- -- on -- -- MC Low Output
-- on -- -- -- -- -- -- -- -- -- on -- -- -- -- MC Very Low Out
Phono-Pre-Amplifier ASR Mini-Basis MK II Page 4