Pultec EQ inductor dissection ;)
« on: February 01, 2007, 02:49:10 PM »
Hi let's go! :)

The beginnigh I take one inducor to make pultec's EQ and I naked the bobin  :oops:

Here are the inductor:
http://www.picvalley.net/u/83/82540_978.JPG

I remove the metal cramb and take the bobin. Here are all parts:
http://www.picvalley.net/u/83/82542_982.JPG

...and the bobin
http://www.picvalley.net/u/83/82541_980.JPG

Wire.
http://www.picvalley.net/u/83/82545_994.JPG
I measure wire thickness 0.25mm:

Some ferrite dimensions:
http://www.picvalley.net/u/83/82543_985.JPG

I use these meters:
http://www.picvalley.net/u/83/82552_418.JPG

To get these values of inductance and DC resistance.
http://www.picvalley.net/u/83/82544_991.GIF


That's all folks  :green:


jensenmann

Pultec EQ inductor dissection ;)
« Reply #1 on: February 01, 2007, 03:56:13 PM »
:shock:
CJ, you´ve got a brother across the pond.

thanks, mate
Pretty low DCR they have at cinemag. It´s much better than the Toko alternative which everybody (and me) used on the Gpultec.
 :thumb:
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

ioaudio

Pultec EQ inductor dissection ;)
« Reply #2 on: February 01, 2007, 05:42:06 PM »
thank you very much for the pics and data!
now i have (one more) in-between-project...

-max

CJ

Pultec EQ inductor dissection ;)
« Reply #3 on: February 01, 2007, 06:33:31 PM »
Nice job, I don't feel so lonely anymore!
Maybe I can get up to Pats to chec jk out an original version.
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

NewYorkDave

Pultec EQ inductor dissection ;)
« Reply #4 on: February 01, 2007, 09:35:12 PM »
You mean, a toroid as opposed to a pot core? That's how I picture it from your description, anyway.

CJ

Pultec EQ inductor dissection ;)
« Reply #5 on: February 02, 2007, 12:07:09 AM »
Inductance is inductance, but yeah, the original was probably a tape wound or powder core torroid. I guess if you wanted to go for the original sond you should wind it like the original, but those pot cores can sound good.
One neat thing about the pot core is that you have a zillion different types of baked goods to chose from, wherre as, with the tape wound, you have 2 mil, 4 mil, and 12 to 14 mil 50/50 or grain. As opposed to an old Phillips or Seimens catalog.

Here is a ferrite baker:
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

gyraf

Pultec EQ inductor dissection ;)
« Reply #6 on: February 02, 2007, 03:58:21 AM »
Nice Dissection - Thanks!

Is it possible to see any markings on either of the two the pot core halves to determine the exact type and/or maker of ferrite?

Jakob E.
..note to self: don't let Harman run your company..

Pultec EQ inductor dissection ;)
« Reply #7 on: February 02, 2007, 04:06:41 AM »
Hi Jakob, there is no any markings on the ferrite cores :(
only cinemag id :(

CJ

Pultec EQ inductor dissection ;)
« Reply #8 on: February 02, 2007, 04:21:30 AM »
There was a place in England that burned down a while back. it was a ware house full of ferrite.  :cry:

I hope they got back up.

Lead hookup is a lot easier with the pot cores, you do not have to loop wire every 87.5 degrees, like you would on a toroid winder.

I can wind some originals, if we can figure out the core.

For people who want to restore the eq to it's original state of ugliness.

 :grin:
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

gyraf

Pultec EQ inductor dissection ;)
« Reply #9 on: February 02, 2007, 04:45:41 AM »
Quote from: "CJ"
There was a place in England that burned down a while back. it was a ware house full of ferrite.  :cry:

I hope they got back up.


Mainline, yes. Nice company - and they're slowly working their way back:

http://www.mainline-group.com/

Jakob E.
..note to self: don't let Harman run your company..


drpat

Pultec EQ inductor dissection ;) New
« Reply #10 on: February 02, 2007, 05:28:56 AM »
...
« Last Edit: September 17, 2010, 10:30:15 AM by drpat »
I use the LA2a on very hot signals like lead vocal.


 

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