Looking for datasheet for microtran input transformer
« on: July 02, 2012, 10:27:36 AM »
I've got a couple of microtran 8030's octal plugin mic input transformers. I'm looking to build them into a couple of MILA's. They are 200/50,000. I can't find a datasheet w/ pinout and suggested zobel anywhere.

I found the bunkerofdoom microtran catalog, but that is about all I can come up with. The catalog says it is a direct replacement for an ampex 1733, I did some digging on that  and also turned up limited info.

(www.bunkerofdoom.com/xfm/microtran74/Microtran974.pdf)

Does anyone have a line on a datasheet for this transformer? Or the ampex 1733?

thanks!


CJ

Re: Looking for datasheet for microtran input transformer
« Reply #1 on: July 02, 2012, 08:51:19 PM »
i took apart a microtran, let me see if i can dig it up, seems to be a pretty good chunk of nickel stuffed into that small can,

anybody try the copper creek salmon from alaska that are running right now?

get that hobachi fired up and lets have a bar b q,  ;D
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

PRR

Re: Looking for datasheet for microtran input transformer
« Reply #2 on: July 03, 2012, 12:39:21 AM »
> can't find a datasheet w/ pinout

Pinout is easy. Ohm meter. Primary is about 20 ohms, or maybe 10 ohms each side of a center-tap. Secondary is several thousand ohms. At least one pin goes to case as shield.

Transformers that old were rarely Zobeled... it will work "OK" with high-Z load. Maybe better with some termination, or an EQ tweak in the amplifier.

> replacement for an ampex 1733

If you can find what gear (tape deck, mixer) that 1733 went into, a peek at the gear schematics will show how Ampex used it (pinout and loading).

Re: Looking for datasheet for microtran input transformer
« Reply #3 on: July 04, 2012, 11:17:04 AM »
Thanks for the tips. Much appreciated. Turns out the microtran catalog was kind of misleading. It is actually a replacement for the the beyer B-17331-1D, not the Ampex 1733-1 as the catalog states.

I managed to dig up the following info from the ampex list and recordist.com...


(from the ampex e-mail list)
"The transformers are the Beyer Peanut, a B-17331-1D (as used in the 351). The 17331 is used in the 351 unterminated and in the 601 with a 2.2M grid leak resistor."

(from recordist.com)
the 601 schemo



the 351 schemo





CJ

Re: Looking for datasheet for microtran input transformer
« Reply #4 on: July 05, 2012, 02:09:01 AM »
there ya go, good work,

i did the 4919 inner-stage, not the input,

but here it is anyway, a lot of ambulance chasers around here, they like to see blood and guts,

http://www.groupdiy.com/index.php?topic=36409.msg449546#msg449546
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html


 

Related Topics

  Subject / Started by Replies Last post
3 Replies
992 Views
Last post December 11, 2008, 08:47:19 AM
by clintrubber
3 Replies
2172 Views
Last post December 03, 2009, 09:33:38 PM
by CJ
1 Replies
1719 Views
Last post October 19, 2014, 07:08:11 PM
by artysan
8 Replies
789 Views
Last post November 11, 2018, 05:41:08 AM
by abbey road d enfer