OK class listen up! Here goes I'll only do this once just for you Bob. (-: .....

Posted by Garth (A) on August 23, 2006 at 06:07:29

In Reply to: directions for the right way? posted by wawa2020 on August 23, 2006 at 05:20:00:

Here is the schematic of the 3440A transformer:

The left side is the primary, cartridge side - the right the secondary, preamp side.

First the secondary side since it is quite simple:
VIOlet is the plus phase or + to the center of the RCA socket
GRaY is the minus phase or - to the outer ring of the RCA socket
The DOT refers to the "in phase" side of the transformer. If one wanted to a simple 4PDT ON-ON switch could be incorporated here between the transfomer and RCA sockets to act as a phase or polarity switch. I bought some switches but haven't tried it yet.

Next the primary side:
For the 37.5ohm tap (the 1:36 gain):
BRowN and YELlow are tied (simply twisted together) and are the plus phase going to the center of the RCA socket
RED and GReeN are tied together and are the minus phase going to the outer ring of the RCA socket
ORanGe and BLUe are left unconnected and isolate them

For the 150 ohm tap (1:18 gain) tie BRN to YEL for plus and ORanGe to BLUe for the minus. RED and GRN from above are left separated and insolate them as well per above.

BLacK and WHIte are tied together and are the external ground point, like a binding post. DONOT attach BLK/WHT to GRY or the minus phase on the primary side.

General rules:

Isolate the RCA sockets from the housing if it is ferric (metal or conductive) if plastic or wood it is not a problem.

DONOT directly ground the primary side with the secondary side.

I put the ground binding post on the primary side since most phono/tonearm cable have a ground connection. Then use an additional wire also from the bnfing post to the ground post on the preamp. If the cables from transformer to preamp have a ground connection for the shiled attach it at the preamp side.

Any questions ask here or email me. (I'm sure I forgot something)

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Follow Ups Full Thread

Topic - CineMag Redux - EBerlin 22:10:40 08/21/06 (15)

Re: CineMag Redux - makarushka 22:20:44 08/22/06 (11)

Re: CineMag Redux - EBerlin 21:18:46 08/23/06 (0)

Nice diagram! /nt\ - anumber1 04:48:50 08/23/06 (9)

Ya, but the phase is wrong and the ... - Garth 05:11:14 08/23/06 (8)

Re: Ya, but the phase is wrong and the ... - makarushka 22:05:10 08/25/06 (0)

directions for the right way? - wawa2020 05:20:00 08/23/06 (2)

OK class listen up! Here goes I'll only do this once just for you Bob. (-: ..... - Garth 08/23/0606:07:29 08/23/06 (1)

Very helpful - thanks Garth (nt) - wawa2020 06:14:42 08/23/06 (0)

Now your gonna make me... - anumber1 05:17:46 08/23/06 (3)

Reefers? (-: (nt) - Garth 05:21:24 08/23/06 (2)

Black Diamonds actually... - anumber1 14:18:33 08/23/06 (1)

Interesting, my bro-in-law does the same for UP from those coal fields to ... - Garth 00:12:46 08/24/06 (0)

Better you tell us what colors went where. - Garth 23:10:00 08/21/06 (2)

Here's what I did... - EBerlin 21:22:43 08/22/06 (1)

I saw the problem immediately.... - Garth 00:32:50 08/23/06 (0)

Follow Ups

OK class listen up! Here goes I'll only do this once just for you Bob. (-: ..... - Garth 08/23/0606:07:29 08/23/06 (1)

Very helpful - thanks Garth (nt) - wawa2020 06:14:42 08/23/06 (0)

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