tofufo7

LEM audio transformer questions
« on: April 22, 2020, 09:59:51 AM »
Hello everybody,
I would like to know if anybody has ever seen that kind of transfo. I think it should be an input one... but... if any detail...
Thank you


CJ

Re: LEM audio transformer questions
« Reply #1 on: April 24, 2020, 04:52:13 AM »
had to resize, comp is not hooked up to local drive in movie screen,  :D

no, never seen it, did you google it?

looks like you need to have someone take it apart.
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

abbey road d enfer

Re: LEM audio transformer questions
« Reply #2 on: April 24, 2020, 07:27:01 AM »
Hello everybody,
I would like to know if anybody has ever seen that kind of transfo. I think it should be an input one... but... if any detail...
Thank you
LEM was a French company that distributed microphones from various mfgrs and also transformers made by Melodium. The Melodium company is extinct now since about 25 years. No documents were saved due to the contentious nature of the termination. Most transformers were custom jobs. unless you can identify what piece of gear they come from, you need to evaluate them by yourself. The methods have been discussed here already. PRR and me have proposed two methods.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

CJ

Re: LEM audio transformer questions
« Reply #3 on: April 24, 2020, 04:36:55 PM »
could be ribbon xfmr, which some people use for moving coil carts

think i hacked one,
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

tofufo7

Re: LEM audio transformer questions
« Reply #4 on: April 24, 2020, 05:11:32 PM »
Hi and thank you so much for your replies.  ;)
In fact, it comes from a card with 8 of them, and I have 2 cards. So, 16 in total.
It was taken from an avintage udio-video system, I think.
LEM was a French company that distributed microphones from various mfgrs and also transformers made by Melodium. The Melodium company is extinct now since about 25 years. No documents were saved due to the contentious nature of the termination. Most transformers were custom jobs. unless you can identify what piece of gear they come from, you need to evaluate them by yourself. The methods have been discussed here already. PRR and me have proposed two methods.
Would be happy to have the link of your two methods, thank you.

CJ

Re: LEM audio transformer questions
« Reply #5 on: April 24, 2020, 11:59:35 PM »
yeah  i did hack a Melodium, different from yours,

ust measure DC resistance and turns ratio if you have a generator and report back

https://groupdiy.com/index.php?topic=67907.msg862950#msg862950
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

mjrippe

Re: LEM audio transformer questions
« Reply #6 on: April 25, 2020, 12:15:04 AM »
And maybe move this to the Magnetics section?

CJ

Re: LEM audio transformer questions
« Reply #7 on: April 25, 2020, 12:27:36 AM »
yes, the poor and lonely Magnetis section.

i don't know, people check in there but they never checkout ,

like hitch hiking in death valley, you might have to wait for a response and die of dehydration,  :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

tofufo7

Re: LEM audio transformer questions
« Reply #8 on: April 27, 2020, 04:25:02 PM »
Hi everybody,
thank you for your advices and link.
Will measure DC resistance and turns ratio... will see.
Best!

ruffrecords

Re: LEM audio transformer questions
« Reply #9 on: April 27, 2020, 05:57:34 PM »
If you can it would be worthwhile also measuring inductance at 100Hz (typically) as this will give you some indication of the kind of impedances it expects to work into/outof.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


 

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