View Full Version : Reading Lpad circuit with 120/240Ti

12-30-2004, 11:13 AM
Could someone help interpreting the Lpad high and mid circuit with the 120Ti/240Ti?

I note in another source that the switches are double-pole-double-throw. I read this on the mid 120Ti network as a circuit with 2.4 ohms plus 1.2 ohms in series, 15 ohms parallel. The b circuit bypasses the 1.2/15 section and thus 2.4 ohms series, and 27 ohms parallel.

Comments appreciated,

12-30-2004, 12:22 PM
1) 3.6 Ohms series, 9.64 Ohms parallel. (15 || 27) -5.2 dB

2) 3.6 Ohms series, 15 Ohms parallel.

3) 2.4 Ohms series, 15 Ohms parallel. -3.0 dB

Assumes switch is three-position: on-off-on.

12-30-2004, 12:43 PM
Thanks, Giskard. I could see the possibility of all comonents in line as one circuit but not the "bypass" of the 1.2 Ohm circuit as the opposite pole.

David F

12-30-2004, 12:51 PM
Brochure says "two-position switch level controls," so 1, 2, & 3 are terminals, not positions. Since it's a two-position switch, 1) and 3), above....

[2) ain't all that bad, tho.... ;) ]

12-30-2004, 02:06 PM
Thanks, Zilch. I noted the reference to use of a DPDT and two attenuation levels in the 120Ti owner's manual.