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FS: BBC am9/19 mic amp modules

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mrclunk

Well-known member
Joined
Nov 29, 2006
Messages
1,091
Location
London
BBC mic and line modules.

AM9/19b
http://www.bbceng.info/ti/eqpt/AM9_19.pdf

Very nice transformer based pre's.
They run on +/- 12VDC but can be run on higher rail voltages if you change a hand-full of resistors.
I've done the maths to run on +/-16vdc but haven't actually tested it.

I'll provide all the docs with them and details of various mods.

I've also designed a little pcb that fits inside the modules to provide switching for +48V, polarity, input pad and the high pass filter.
It uses sub-miniature pcb mount toggles and a couple of Panasonic relays. Gives  four switches just above the gain control.
I'm waiting on the prototypes from china, but when i get the final batch i'll let buyers know. They'll be about £7 each.
I have these listed on ebay also.

£100 each plus shipping.

AM7/13A Line modules.
You can use these as mic amps too with a resistor change, great on drums in my experience.

£60 each for untouched ones
£75 each for ones that i've added a gain control too.
thanks
Paul

mr clunk g mail
 

jamierichards7

New member
Joined
Sep 4, 2016
Messages
3
Hi, I've just got hold of some AM7/13 high gain line amp modules (with power supply).  I haven't had a chance to look at them properly yet but I was wondering if you would mind sharing any info regarding what you did to modify them for studio use? Which resistors did you change and how did you add the gain control? 

Any help much appreciated.

Cheers,

Jamie
 

mrclunk

Well-known member
Joined
Nov 29, 2006
Messages
1,091
Location
London
jamierichards7 said:
Hi, I've just got hold of some AM7/13 high gain line amp modules (with power supply).  I haven't had a chance to look at them properly yet but I was wondering if you would mind sharing any info regarding what you did to modify them for studio use? Which resistors did you change and how did you add the gain control? 

Any help much appreciated.

Cheers,

Jamie
Yeah of course.
Ill send them over when i have a mo.
 

mrclunk

Well-known member
Joined
Nov 29, 2006
Messages
1,091
Location
London
well reminded.
Basically u stick a 600ohm resistor across the input Tx primaries and then make switched resistor ladder for gain control.

 
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