RC Filter Progress To Date

Posted by Maxamillion (A) on May 8, 2010 at 09:19:11

I'm still waiting for the TX2575 resistors from Texas Components, but in the meantime I've done some experimentation using PRP resistors, Multicaps and Silver Mica caps. I feel that the best sounding capacitor combination on my system is a cascade of 4 silver mica caps, so that is what I'm going with. The cascade will be 2200pF, 1800pF, 180pF and 18pF, all connected to a 71 ohm TX2575 resistor to match the characteristic impedance of my speaker cables, giving a -3db point of ~530KHz, right at the bottom of the AM band, and far enough away from the audio band to cause no concerns.

I have built 4 small boxes of TI-shield which fit inside an ABS plastic potting box about 1 3/16" X 1 3/4" x 1/2" OD (Mouser Electronics). The attached picture shows an empty potting box with lid, the TI-shield box alone, the TI-shield box inside a potting box, and the cascaded caps. Once I get the TX2575 resistors I will assemble it all and experiment with grounding arrangements for the TI-shield, i.e. none, grounded to the (-) leg of the speaker cable ala Walker, and grounded to earth ground at an outlet ala our own cdc. I will also need to decide how I will damp/insulate the circuit from the shield - right now I'm leaning toward potting the entire assembly with epoxy potting compound.

The whole completed assembly is only 1 3/4" long and will fit very nicely either over or under the speaker and amp binding posts. Also, putting the TI-shield inside the box gives IMHO a nicer exterior appearance, and prevents the shield from ever shorting across the binding posts.

Stay tuned.

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Topic - RC Filter Progress To Date - Maxamillion 09:19:11 05/8/10 (33)

Museum Wax - Al Sekela 14:59:16 05/9/10 (21)

My Latest Damping Thoughts - Maxamillion 08:43:46 05/10/10 (19)

Listen for the sonic consequences of the Mortite. - Al Sekela 11:07:26 05/10/10 (18)

RE: Listen for the sonic consequences of the Mortite. - Maxamillion 11:21:15 05/10/10 (17)

Filters Done - Pictures - Maxamillion 20:02:30 05/10/10 (16)

Nice! Please keep us informed. (nt) - Al Sekela 14:50:47 05/11/10 (0)

RE: Filters Done - Pictures - JimBop 14:47:56 05/11/10 (12)

RE: Filters Done - Pictures - Maxamillion 21:01:07 05/11/10 (11)

RE: Filters Done - Pictures - JimBop 16:54:55 05/12/10 (4)

RE: Filters Done - Pictures - Maxamillion 04:15:22 05/13/10 (3)

RE: Filters Done - Pictures - JimBop 08:32:19 05/13/10 (1)

RE: Filters Done - Pictures - Maxamillion 09:59:21 05/13/10 (0)

Rest of the answer, Jim - Maxamillion 04:28:12 05/13/10 (0)

Good work, Max - bartc 06:08:46 05/12/10 (5)

Potted Late Last Night - Maxamillion 07:05:28 05/12/10 (4)

Picture of the potted RC Filters - Maxamillion 04:38:28 05/13/10 (3)

RE: Picture of the potted RC Filters - bartc 05:47:47 05/13/10 (2)

RE: Picture of the potted RC Filters - Maxamillion 06:10:59 05/13/10 (1)

Max, you're in for a whole new adventure! - bartc 06:16:12 05/13/10 (0)

Good job...nt - rwiley 07:11:38 05/11/10 (0)

Keep us posted nt - bartc 05:42:21 05/11/10 (0)

RE: Museum Wax - Maxamillion 16:04:40 05/9/10 (0)

RE: RC Filter Progress To Date - Dave Garretson 16:19:49 05/8/10 (1)

RE: RC Filter Progress To Date - Maxamillion 16:33:35 05/8/10 (0)

Interesting Potting/Vibration Absorption Compound - GelWax - Maxamillion 16:19:04 05/8/10 (8)

I used to put gelwax in my speaker cables - Dawnrazor 07:41:59 05/11/10 (1)

RE: I used to put gelwax in my speaker cables - Maxamillion 08:05:31 05/11/10 (0)

Whoah! - bartc 17:33:19 05/8/10 (5)

RE: Whoah! - Maxamillion 17:53:51 05/8/10 (4)

RE: Whoah! - John V 00:50:38 05/19/10 (3)

Linseed oil? - bartc 06:16:32 05/19/10 (2)

RE: Linseed oil? - John V 15:52:15 05/26/10 (0)

RE: Linseed oil? - John V 15:18:46 05/19/10 (0)

RC Filter Progress To Date

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