Author Topic: Cinemag 2610-IT transformer? Check here for information  (Read 1828 times)

rotation

  • Member
  • Posts: 402
  • slovenia
Cinemag 2610-IT transformer? Check here for information
« on: November 23, 2009, 02:47:00 PM »
Hi,

i ordered several transformers from Cinemag and got this 2610-IT inside the package. It looks like they made a mistake and sent me 1 2610-IT, and one CMMI-7C instead  of 2 CMMI-7C. The rest was ok.
I only found one information about this transformer, it says it was used by UA for "recreation" of M610 preamp. IIRC, this preamp uses 1:7 mic input, so 2610-IT is probably the same ratio.
Before bothering Cinemag, i thought i might ask here if anyone knows this particular transformer. For now i can't test it myself because i might send it back or sell here. Can anyone say something about it?

Miha

p.s.: i hope this is the place to post this, if not
mods please move it.
« Last Edit: November 25, 2009, 05:06:26 PM by rotation »


Sleeper

  • Member
  • Posts: 653
  • Los Angeles
Re: Anyone knows Cinemag 2610-IT transformer?
« Reply #1 on: November 23, 2009, 04:52:03 PM »
I'm not sure if it's the same transformer, and you should obviously just call cinemag, they won't be bothered.
But DO let us know if the CMMI 7c and the 2610 are the same thing, it's quite possible that the 2610 is just a CMMI 7C with different paint. That's something people around here would want to know.

rotation

  • Member
  • Posts: 402
  • slovenia
Re: Anyone knows Cinemag 2610-IT transformer?
« Reply #2 on: November 23, 2009, 05:54:26 PM »

Ok, i will contact them and let you know what i find out.

Miha

mitsos

  • Member
  • Posts: 2590
Re: Anyone knows Cinemag 2610-IT transformer?
« Reply #3 on: November 25, 2009, 06:36:47 AM »
any news? By accident found that it was used in the 2108 preamp.

http://www.groupdiy.com/index.php?topic=34946.0

rotation

  • Member
  • Posts: 402
  • slovenia
Re: Anyone knows Cinemag 2610-IT transformer?
« Reply #4 on: November 25, 2009, 03:49:05 PM »

Not yet. Be sure i will let you know when i get reply.
I've seen that thread, it doesn't say much.

Miha

rotation

  • Member
  • Posts: 402
  • slovenia
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #5 on: November 25, 2009, 05:15:16 PM »

Ok, i just got reply, 8 hours after sending question.
2610-IT is the same as Cinemag CMMI-7C. They mark some of them with a custom number for a military application :o
Hmm, now i'm wondering why would military need high quality mic input transformer?

CJ

  • Member
  • Posts: 9608
  • California
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #6 on: November 26, 2009, 12:40:57 PM »
to hear torpedos with...
If I can't fix it, I can fix it so nobody else can!
Frank's- www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar- http://tdsl.duncanamps.com/schematics.php

dissonantstring

  • Member
  • Posts: 1053
  • san jose, ca.
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #7 on: November 30, 2009, 03:46:57 PM »
hi rotation,
thank you for verification on the CMMI-7C! (thumbs and beers).

if your transformers are the ones with leads would you be so kind as to verify that the leads are the same with both the 2610-IT and the CMMI-7C?

this info would also be helpful for future reference.
kindest regards,
grant

mitsos

  • Member
  • Posts: 2590
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #8 on: November 30, 2009, 07:46:47 PM »
grant
how's the 2108 project going? did you end up getting the boards from Vas?

dissonantstring

  • Member
  • Posts: 1053
  • san jose, ca.
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #9 on: December 01, 2009, 03:33:38 PM »
hi mitsos,
i've just sent payment to vas yesterday and will start working on things when i get the PCB delivered.  Vas said he has worked on a BOM from his unit and spare, so hopefully we'll have a good starting point for everything.  i'll work on refining the BOM and scanning the PCB.  i don't think that any of the parts are so difficult to obtain (i actually might have most of it already, except a few transistors, resistor values, etc).
 
since there is no schematic for this circuit, i'll try to work on that as well and break it down into manageable parts for each section (input amp, gain controls, output amp, utilities, metering, etc).  this would be my first really big reverse job, so it may take some time.  i'll definitely give what i can back to the forum from this research.  possibly try to simplify it so there is an easier project which has the same sonic qualities that all could do.

my time is becoming limited nowdays due to my family situation, work, studio and with the holidays approaching, but i'll keep this going.

kind regards,
grant


dissonantstring

  • Member
  • Posts: 1053
  • san jose, ca.
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #10 on: December 01, 2009, 03:35:01 PM »
hi miha,
any word on the leads being the same on both the 2610-IT and the CMMI-7C?

rotation

  • Member
  • Posts: 402
  • slovenia
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #11 on: December 01, 2009, 07:09:33 PM »
hi rotation,
thank you for verification on the CMMI-7C! (thumbs and beers).

if your transformers are the ones with leads would you be so kind as to verify that the leads are the same with both the 2610-IT and the CMMI-7C?

this info would also be helpful for future reference.
kindest regards,
grant

Hi,

no problem, it's a pleasure for me if i can be of any help to you guys.

Leads on CMMI7-C and 2610-IT do have the same color, cans look the same too!
I have other two CMMI-7C from older batch and they have shinier cans. But the top of the can looks the same on all three. I know this is not important, i just wanted to let you know what i have here.

Miha

dissonantstring

  • Member
  • Posts: 1053
  • san jose, ca.
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #12 on: December 03, 2009, 02:06:38 PM »
great!  thank you miha!

it may be a good idea to ohm out the leads to make sure that they are also the same with regards to the CMMI-7C transformer wiring/color codes and also note if the resistance is also the same between windings on each transformer.

cheers,
grant

rotation

  • Member
  • Posts: 402
  • slovenia
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #13 on: December 03, 2009, 04:07:25 PM »

Hi,

i thought about this, but i'm still not sure if it's good idea. I read that the core will magnetize and cause some problems.
Is this truth? I could never get solid answer.

Miha

emrr

  • Member
  • Posts: 4837
  • NC, USA
    • http://www.emrrecorders.com/
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #14 on: December 04, 2009, 12:03:19 AM »
I'll keep voting for 'nonsense', until I see/hear evidence with my own eyes/ears.  As they say, reverse your test leads and test again; mag/de-mag, no?   I don't think it matters.  Nothing from the golden age of audio would still work to this day if everything got f$^% by magnetization. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounded g

CJ

  • Member
  • Posts: 9608
  • California
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #15 on: December 04, 2009, 03:54:17 AM »
you can put a battery on a transformer and notice a drop in the inductance reading,

depends on the core, and.......














































the battery!  :D
If I can't fix it, I can fix it so nobody else can!
Frank's- www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar- http://tdsl.duncanamps.com/schematics.php

rotation

  • Member
  • Posts: 402
  • slovenia
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #16 on: December 06, 2009, 11:45:09 AM »
great!  thank you miha!

it may be a good idea to ohm out the leads to make sure that they are also the same with regards to the CMMI-7C transformer wiring/color codes and also note if the resistance is also the same between windings on each transformer.

cheers,
grant

Hey,

this is CMMI-7C datasheet for color codes (same for both transformers):
http://www.cinemag.biz/mic_input/CMMI-7C.pdf

CMMI-7C PRI and SEC DCR:

PRI upper half winding=11,9ohm
PRI lower half winding=12ohm
Both windings in series=23,9ohm
........................................
Secondary winding=1300ohm

2610-IT PRI and SEC DCR:

PRI upper half winding=12ohm
PRI lower half winding=12ohm
Both windings in series= 23,8ohm
.........................................
Secondary winding=1290ohm

So this two transformers and their color codes are the same, this is what a guy from Cinemag already told me.
Note tha my DVM is cheap one. From my experiences primary reading here is more or less ok, but secondary might be a few percent off.

I compared my results to those from CJ's hack. Primary DCR on mine is a little higher, secondary is the same. But CJ's version had single primary and secondary:
http://www.groupdiy.com/index.php?topic=36324.0

Let me know if you want me to measure something more. 2610-IT will probably have to go in a few days...

Miha
« Last Edit: December 06, 2009, 11:47:22 AM by rotation »

dissonantstring

  • Member
  • Posts: 1053
  • san jose, ca.
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #17 on: December 06, 2009, 12:37:54 PM »
hi miha,
thank you for testing the two transformers.

i think it's pretty well confirmed that the CMMI-7C (current off the shelf Cinemag mic input transformer) and the 2610-IT (custom UA input mic transformer) are the same transformer as expressed by Cinemag and also the same as the W'OB special designed for UA that CJ dissected (minus the multi input impedance connections).  

I think we can now say that anyone building a 610, 2108 or R47 type mic pre will be good to go with a CMMI-7C from Cinemag.  We have W'OB to thank for designing this great mic input transformer.  
stamp this one: VERIFIED
cheers,
grant

mitsos

  • Member
  • Posts: 2590
Re: Cinemag 2610-IT transformer? Check here for information
« Reply #18 on: December 06, 2009, 10:03:50 PM »
You can also use the Altran C-3799-8, which UA is using on the some 610s, see Pucho's photos:

http://www.groupdiy.com/index.php?topic=13038.msg371953#msg371953


 

Related Topics

  Subject / Started by Replies Last post
20 Replies
5772 Views
Last post January 26, 2005, 11:48:23 AM
by rafafredd
5 Replies
738 Views
Last post August 20, 2005, 12:41:40 PM
by pucho812
4 Replies
930 Views
Last post September 08, 2010, 07:05:47 PM
by sahib
65 Replies
2849 Views
Last post November 24, 2013, 06:48:13 AM
by Eliani
1 Replies
262 Views
Last post October 17, 2013, 10:52:49 AM
by keefaz