Transformers 10k:10k vs. 600:600

Hi!

What's the difference of a 10k:10k transformer vs. a 600:600 ? (Ohm)

Required inductance for starters.  This has been covered in depth here already, anyone have a quick link to some red meat?

Maybe we should have a transformers meta?
Cheers

ian

Generally speaking ;  the 10K:10K type are for input, and 600:600 for output.

best

M.

mik said:

Generally speaking ;  the 10K:10K type are for input, and 600:600 for output.

best

M.

Click to expand...

AFAIK In modern standards this is right, in old school when power was expensive matching Z was for saving it, so a device that could drive 600Ω didn't work at 10K and loose all that power, now the power is not expensive so the compromise make it more situable to bridging so 10K at inputs and 600Ω at outputs make more sense, beter frec response and compatibility and one output can drive multiple inputs without looses...

JS

I have an old yamaha mixer with 600:600 transformers on the inputs.

I'm using it as a summing mixer, my interface is going straight into the input channels.

It sounds fine as is, but should I look into changing these out? Or will I find there is no difference with other transformers? How would the frequency responce change?

In general terms he LP will be lower and low end will be cleaner but depending on the source output Z and the inductance of the transformers may not worth it, if it isn't broken don't fix it... Hi end depends more on the construction of the transformers.

If you like how it sounds you shouldn't mod it, unless you are expecting more, maybe you could try and choose which you like it most. I wouldn't change those...

JS

There's nothing wrong with that. Modern gear has a low output Z, just not much current drive.

Thanks folks!

I thought secondary ohm was dependent on primary ohm, in a square relationship. Isn't that right?
Or can I measure 600ohm just unconnected for a 600:600 primary/secondary?

Sorry if this is very basic/newbie questions to you..
Yes, a transformer meta would be nice. Both for the theoretical and more practical sides of transformers.

Just go through CJ's post history, you should be able to find just about everything you ever needed to know about transformers.

ruffrecords said:

Maybe we should have a transformers meta?
Cheers

ian

Click to expand...

G-Sun said:

Yes, a transformer meta would be nice. Both for the theoretical and more practical sides of transformers.

Click to expand...

I totally agree with this, I find myself making some basic question about transformers, and would be nice to have a reference thread. I found a Jensen paper with useful info in http://www.jensen-transformers.com/an/Audio%20Transformers%20Chapter.pdf

gemini86 said:

Just go through CJ's post history, you should be able to find just about everything you ever needed to know about transformers.

Click to expand...

Maybe a good starting point...

G-Sun said:

Thanks folks!

I thought secondary ohm was dependent on primary ohm, in a square relationship. Isn't that right?
Or can I measure 600ohm just unconnected for a 600:600 primary/secondary?

Click to expand...

In one word, no. You need to measure it with AC, and the result is an impedance. A transformer winding being an inductance, the impedance varies with frequency. There may be a point where you 600ohm winding may measure 600ohms, or your 10k winding will measure 10k, but this is to be taken in relationship with frequency.
To confuse you more, ther is probably a point (frequency) where your 600 ohm winding measures 10k...
Qualifying a xfmr by its impedance is convenient, but it is not an intrinsic parameter. The inductance is an intrinsic parameter.
The inductance is a limiting factor. The resulting impedance varies with frequency; at near-zero frequency, the impedance is equal to the DCR. In order to qualify for let's say 600 ohms, the inductive part of the winding's impedance must be higher than 600 ohms at the lowest frequency of interest. You see that the targetted application is significant there; transformers spec'd for 20Hz LF cut-off need a higher inductance than those designed for 50 Hz.
I agree an "inductive components" meta is more and more needed.

abbey road d enfer said:

You see that the targetted application is significant there; transformers spec'd for 20Hz LF cut-off need a higher inductance than those designed for 50 Hz.
I agree an "inductive components" meta is more and more needed.

Click to expand...

Thanks a lot! I'm starting to grasp it a little. But, frequency: don't we in pro-audio always need to design for at least 20Hz? And would that change from a mic-out to a preamp-in?

What about this transformer meta already created by the aforementioned CJ?

http://www.groupdiy.com/index.php?topic=467.0

vineyardgray said:

What about this transformer meta already created by the aforementioned CJ?

http://www.groupdiy.com/index.php?topic=467.0

Click to expand...

It's 8 years old and a lot of links don't work... But still has some usefull info.

JS

G-Sun said:

But, frequency: don't we in pro-audio always need to design for at least 20Hz?

Click to expand...

That's what good practice suggests, but there are some exceptions. For example 70/100V xfmrs for distributed sound systems are generally spec'd for 40-50 Hz. And some vintage units may have used a different set of rules.

Thanks a lot!
Yes, I'll read up on stuff from the old meta

from Grossner, Transformers for Electronic Circuits pg. 179:

"because the circuit behavior is least complicated at  wm, it is customary to specify several important transformer characteristics at the mid-band frequency:
(1) the rated power
(2) either the turns ratio or the desired impedance seen at the input when the secondary is loaded; and
(3) the desired minimum efficiency, or the maximum insertion loss (also called flat loss)."

and a good point is made above on the transformer Z dropping to zero, at which time you have a current source feeding the transformer instead of a voltage source,

current transformers operate down near zero input Z, the pri is just one wire,

that meta is pretty stale, just a bunch of vendor links,

ok, i moved the article section in the Transformer Meta to the top of the page,

not enuff space to add these bookmarks to the meta, error message: "warning! yo have gone over 20,000,000 words

start with these two:

here is a start from the Jensen site:
http://jensen-transformers.com/an/Audio%20Transformers%20Chapter.pdf

very historical, starts out: "Fred Flintstone discovered a compass in 1498 BC,..."

http://www.sowter.co.uk/pdf/GAVS.pdf

so here>

http://www.alcatel-lucent.com/bstj/vol07-1928/articles/bstj7-4-762.pdf

http://www.rsp-italy.it/Electronics/Magazines/General%20Radio%20Experimenter/General%20Radio%20Experimenter%201942%2003.pdf
http://powerelectronics.com/mag/power_inductors_equivalent_circuit/
http://www.vias.org/eltransformers/lee_electronic_transformers_06_10.html
http://www.classicaudio.ru/articles/ot_distortion_p2_a57.pdf
http://www.junkbox.com/electronics/utc_transformer_catalog_1963.pdf
http://www.jensen-transformers.com/an/Audio%20Transformers%20Chapter.pdf
http://www.coilwinder.com/Magnet%20wire%20data.htm
http://books.google.com/books?id=wyiFxKP2OnQC&pg=PA169&lpg=PA169&dq=supermendur&source=bl&ots=653QJBp_Rc&sig=ktT4pc_UfrL47GPdWsSvO0penTQ&hl=en&sa=X&ei=UK_KUIGLAc6ajAKOloC4DQ&ved=0CEcQ6AEwBDgK#v=onepage&q=supermendur&f=false
http://www.infernalemachine.fr/TECH/NEUMANN/U47Tranny_Winding.pdf
http://www.vias.org/matsch_capmag/matsch_caps_magnetics_chap3_18.html
http://www.micrometals.com/material/pc_coreloss_txt.html
http://www.professionalplastics.com/NOMEXPAPER
http://www.tubetvr.com/transformers.pdf
http://richard984.tripod.com/transformer_math.htm
http://info.ee.surrey.ac.uk/Workshop/advice/coils/gap/index.html
http://info.ee.surrey.ac.uk/Workshop/advice/coils/mu/
http://books.google.com/books?id=axyWXjsdorMC&pg=PA354&dq=mu+metal&hl=en#v=onepage&q=mu%20metal&f=false
http://www.aircraftmaterialsuk.com/data/electronic/almu.html
http://cartech.ides.com/datasheet.aspx?i=103&e=206&c=TechArt
http://books.google.com/books?id=ufGdyu24X2EC&pg=PA388&lpg=PA388&dq=4-79+permalloy+relative+perm&source=bl&ots=_YaxrcL_EL&sig=641hSSUJP0jsusY30qpcf6AmEGc&hl=en&sa=X&ei=8BKvUMqHDae9iwLnu4HwDA&ved=0CD8Q6AEwAw#v=onepage&q=4-79%20permalloy%20relative%20perm&f=false
http://www.magmet.com/lamination/pdf/Superperm49.pdf
http://www.coilgun.info/theorymath/home.htm
http://www.ebay.com/itm/Magnet-Wire-26-AWG-Gauge-Enameled-Copper-155C-5lb-6290ft-Magnetic-Coil-Green-/251135985868?pt=LH_DefaultDomain_0&hash=item3a78df08cc
http://diyaudioprojects.com/Technical/American-Wire-Gauge/
http://www.laminationspecialties.com/

http://www.tempel.com/products.asp?cat=11

http://en.wikibooks.org/wiki/Electronics/Transformer_Design

http://ia700401.us.archive.org/31/items/ElectronicTransformersAndCircuits/Lee1955ElectronicTransformersAndCircuits.pdf

http://www.magmet.com/lamination/

http://jensen-transformers.com/

CJ said:

from Grossner, Transformers for Electronic Circuits pg. 179:

"because the circuit behavior is least complicated at  wm, it is customary to specify several important transformer characteristics at the mid-band frequency:
(1) the rated power
(2) either the turns ratio or the desired impedance seen at the input when the secondary is loaded; and
(3) the desired minimum efficiency, or the maximum insertion loss (also called flat loss)."

and a good point is made above on the transformer Z dropping to zero, at which time you have a current source feeding the transformer instead of a voltage source,

current transformers operate down near zero input Z, the pri is just one wire,

that meta is pretty stale, just a bunch of vendor links,

ok, i moved the article section in the Transformer Meta to the top of the page,

not enuff space to add these bookmarks to the meta, error message: "warning! yo have gone over 20,000,000 words

start with these two:

here is a start from the Jensen site:
http://jensen-transformers.com/an/Audio%20Transformers%20Chapter.pdf

very historical, starts out: "Fred Flintstone discovered a compass in 1498 BC,..."

http://www.sowter.co.uk/pdf/GAVS.pdf

so here>

http://www.alcatel-lucent.com/bstj/vol07-1928/articles/bstj7-4-762.pdf

http://www.rsp-italy.it/Electronics/Magazines/General%20Radio%20Experimenter/General%20Radio%20Experimenter%201942%2003.pdf
http://powerelectronics.com/mag/power_inductors_equivalent_circuit/
http://www.vias.org/eltransformers/lee_electronic_transformers_06_10.html
http://www.classicaudio.ru/articles/ot_distortion_p2_a57.pdf
http://www.junkbox.com/electronics/utc_transformer_catalog_1963.pdf
http://www.jensen-transformers.com/an/Audio%20Transformers%20Chapter.pdf
http://www.coilwinder.com/Magnet%20wire%20data.htm
http://books.google.com/books?id=wyiFxKP2OnQC&pg=PA169&lpg=PA169&dq=supermendur&source=bl&ots=653QJBp_Rc&sig=ktT4pc_UfrL47GPdWsSvO0penTQ&hl=en&sa=X&ei=UK_KUIGLAc6ajAKOloC4DQ&ved=0CEcQ6AEwBDgK#v=onepage&q=supermendur&f=false
http://www.infernalemachine.fr/TECH/NEUMANN/U47Tranny_Winding.pdf
http://www.vias.org/matsch_capmag/matsch_caps_magnetics_chap3_18.html
http://www.micrometals.com/material/pc_coreloss_txt.html
http://www.professionalplastics.com/NOMEXPAPER
http://www.tubetvr.com/transformers.pdf
http://richard984.tripod.com/transformer_math.htm
http://info.ee.surrey.ac.uk/Workshop/advice/coils/gap/index.html
http://info.ee.surrey.ac.uk/Workshop/advice/coils/mu/
http://books.google.com/books?id=axyWXjsdorMC&pg=PA354&dq=mu+metal&hl=en#v=onepage&q=mu%20metal&f=false
http://www.aircraftmaterialsuk.com/data/electronic/almu.html
http://cartech.ides.com/datasheet.aspx?i=103&e=206&c=TechArt
http://books.google.com/books?id=ufGdyu24X2EC&pg=PA388&lpg=PA388&dq=4-79+permalloy+relative+perm&source=bl&ots=_YaxrcL_EL&sig=641hSSUJP0jsusY30qpcf6AmEGc&hl=en&sa=X&ei=8BKvUMqHDae9iwLnu4HwDA&ved=0CD8Q6AEwAw#v=onepage&q=4-79%20permalloy%20relative%20perm&f=false
http://www.magmet.com/lamination/pdf/Superperm49.pdf
http://www.coilgun.info/theorymath/home.htm
http://www.ebay.com/itm/Magnet-Wire-26-AWG-Gauge-Enameled-Copper-155C-5lb-6290ft-Magnetic-Coil-Green-/251135985868?pt=LH_DefaultDomain_0&hash=item3a78df08cc
http://diyaudioprojects.com/Technical/American-Wire-Gauge/
http://www.laminationspecialties.com/

http://www.tempel.com/products.asp?cat=11

http://en.wikibooks.org/wiki/Electronics/Transformer_Design

http://ia700401.us.archive.org/31/items/ElectronicTransformersAndCircuits/Lee1955ElectronicTransformersAndCircuits.pdf

http://www.magmet.com/lamination/

http://jensen-transformers.com/

Click to expand...

Holy crap batman!  8)

Sorry for digging up.
Been reading a while, still have a question...
I have an Ampex 600 that I am rebuilding. The line input is unbalanced, 10K.
I want to have it transformer balanced, and I have 600:600 Edcors... I'll try them anyway, but should I start looking for 600:10K in order to avoid problems?
I know transformers acts kind of as a lens, so my guess is that if I feed the input of my tape machine with a modern line level / impedance it should be about fine (approx 10K) but if I use the output let's say of my 1176, which is 600 ohms, then the tube will see 600 ohms input and I'll have a shitty freq response?
Sorry if dumb question...