OEP Z3003E transformer

[shot]

Hi all,

I was wondering what is the quality of OEP Z3003E transformer.
Has anyone compared it with similar 10K:10K transformers?

I got a great deal on a pack of those transformers that I couldn't resist buying. A deal good enough to buy them without a lot of research. But when I went to research more about it I've noticed that it is rarely mentioned. Not here, not on other forums. But I found a lot of places where it can be bought, so I guess it is present on the market. It is mid-low priced and it is supposed to be better than the rest of the OEP product line. Datasheet from the manufacturer seems fine (but it could be just propaganda).

Any experiences?




Luka

 

[emrr]

Not doing the math, inductance looks low.  I'd say it probably doesn't perform well in a matching scenario, probably fine when bridging.  I wouldn't expect much as a tube interstage, in other words. 

 

[ruffrecords]

I did some tests on a range of transformers some time ago and posted the resuslts here. Other group memebers contributed their own data which I added to the document:

http://www.ianbell.ukfsn.org/EzTubeMixer/docs/EzTubeMixer/Iron/TransformerInductance.pdf

The Z3003 was tested by Mathis D and the results are included in the above document. The Z3003 has a reasonable primary inductance so it should have a good LF response with normal source impedances. Its specification is a bit wooly about distortion. It says its distortion is less than 1% at +20dB which is pretty meaningless.

Cheer

Ian

 

[ruffrecords]

I jst noticed the Z3003 is £21 at RS but only £13 at Canford.

Cheers

Ian

 

[shot]

And I just scored a bunch for around £4.2 per piece! Including shipping!
;D

 

[ruffrecords]

And I just scored a bunch for around £4.2 per piece! Including shipping!
;D

Lucky devil!!

Cheers

ian

 

[MatthisD]

Very high DCR to inductance ratio. The core is most likely radiometal but it has a slightly larger lamination than A2 series but at the same time not a lot of lams in the stack. It does not saturate with 20Hz at line level. Secondary needs loading to flatten the high end as far as I can remember.

 

[ruffrecords]

Very high DCR to inductance ratio. The core is most likely radiometal but it has a slightly larger lamination than A2 series but at the same time not a lot of lams in the stack. It does not saturate with 20Hz at line level. Secondary needs loading to flatten the high end as far as I can remember.

I can verify this. I just bought a couple and tested them Secondary DCR is 1950 ohms and inductance at 100Hz was 66 Henries. There's a 3dB bump in the response at 25KHz with the secondary unloaded but with a 10K load it is flat nearly to 40KHz. Distortion at 1KHz at +18dBu in was less than 0.1% ( both measurements on my Lindos)

Using RTA I get the attached graph for distortion vs frequency. Not quite sure what the level was.

Cheers

Ian

 

[PRR]

> Very high DCR

FWIW: I had some high-cost bridging transfos rated for 20K in and measuring 10K DCR.

And the voltage ratio was 6dB shy of what the impedance ratio implied.

Curious, I busted one open, and found two 4.7K resistors in series.

Whatever you did to the other side, that primary was NOT going to short-out the bus it was bridging.

We could think the same about 2K DCR on a 10K nominal impedance. Short the secondary, and even a TL071 could still swing full level across the primary.

But I think it is just a super small-size low-cost transformer.

 

[ruffrecords]

But I think it is just a super small-size low-cost transformer.

I have seen smaller and cheaper that perform remarkably well. The core looks to me to be about 1 inch by 1.5 inches cross section and about a quarter inch thick. I know zilch about transformer design but perhaps CJ would like to chime in with what that means in terms of signal handling capability etc.

Cheers

Ian

 

[MatthisD]

But I think it is just a super small-size low-cost transformer.

I have seen smaller and cheaper that perform remarkably well. The core looks to me to be about 1 inch by 1.5 inches cross section and about a quarter inch thick. I know zilch about transformer design but perhaps CJ would like to chime in with what that means in terms of signal handling capability etc.

Cheers

Ian

It is (probably) stacked with this lamination:
http://www.magmet.com/lamination/2627ee.php

...similar if not the same lamination as this Triad:
http://groupdiy.com/index.php?topic=35991.msg441941#msg441941

With two electrostatic shields it must be at least a 3 section coil so not the cheapest of cheap winding structures. Its €28 +vat and another €13 for a mu-can from RS which comes to €50 altogether.

 

[sahib]

And I just scored a bunch for around £4.2 per piece! Including shipping!
;D

Lucky devil!!

Cheers

ian

Otherwise known as here in Scotland " you jammy bastard"  ;D

Weldone.

 

[ruffrecords]

With two electrostatic shields it must be at least a 3 section coil so not the cheapest of cheap winding structures. Its €28 +vat and another €13 for a mu-can from RS which comes to €50 altogether.

And yet is is just £13 from Canford. For my purposes as a line level input inside a screened box, the mu-metal screen is not necessary. The mu-metal screen is only £5 from Canford.

Cheers

Ian