edcorusa
Active member
I have had many comments and questions lately about Nickel core transformers and here are some of the FAQ?s and our comments. EDCOR has been reluctant to stock and use
Ni core material because the cost factor. Ni (80%) costs about 10 times the cost of M6 steel. This equates in the cost of a transformer about 4 times using Ni vs M6.
Now lets? discuss the goods the bad and the fun. Other than the cost what are the real differences. The Ni core has a much higher ac (incremental) permeability. So what! is the effect? The inductance is higher by the permeability factor related to M6. It is the inverse root of the permeability of Ni to M6. Now try to find out what the ac permeability is of either Ni or M6. Tests to us indicate number of about 36 to 50 and the square root is somewhere between 6 and 7. So, the inductance will be 6-7 times more if you use an 80% Ni core instead of M6. The turns equal, of course. Therefore the turns needed to achieve a defined inductance can be 6-7 times less. This is all super secret stuff so don?t mention it to anyone and if you do please don?t mention the source.
Lets? add another factor. Ni and M6 have real different saturation and distortion characteristics. Forgive me, but M6 saturates at about 17,000 gauss and Ni about 5,000 gauss. The 1% distortion levels are at about 14,000 gauss and 4,000 gauss. Now what do you suppose one of the key ingredients is in the determination of primary turns? Walla,
it is the flux density and so as the flux goes down the turns must go up in a direct proportion. The saturation curves look really different on the scope and I am sure they sound really different, like sharp to smooth. Walla, again.
So, where do we go from here? The Ni material is far too expensive for a tube output transformer and the AC input voltage is controlled inversely by the flux density, so M6 is the only acceptable material for a modern day output transformer. Today we cannot purchase Ni material larger than EI75 without committing to large quantity. If we commit to a THD level of 1% the Ni transformer would be 3 times the size of a M6 core and only 12 times the cost, so lets? be practical. Pleeze.
I have tested gapped core (single ended) transformers. The Ni and M6 cores have the same characteristics when gapping the core. Major losses in core efficiency result. That causes a single ended transformer to be about twice the size as a PP. Right! So forget Ni in a SET unless it is low power, low DC current and low input AC voltage.
Where does the Ni core have value? Low input voltage, low power, high inductance, low frequency and they really looks good and sounds good.
EDCOR Electronics now has Ni cores for XSM, WSM and some low power or low voltage transformers, too.
If you have any other information to add please do so. I am always interested in information.
Ni core material because the cost factor. Ni (80%) costs about 10 times the cost of M6 steel. This equates in the cost of a transformer about 4 times using Ni vs M6.
Now lets? discuss the goods the bad and the fun. Other than the cost what are the real differences. The Ni core has a much higher ac (incremental) permeability. So what! is the effect? The inductance is higher by the permeability factor related to M6. It is the inverse root of the permeability of Ni to M6. Now try to find out what the ac permeability is of either Ni or M6. Tests to us indicate number of about 36 to 50 and the square root is somewhere between 6 and 7. So, the inductance will be 6-7 times more if you use an 80% Ni core instead of M6. The turns equal, of course. Therefore the turns needed to achieve a defined inductance can be 6-7 times less. This is all super secret stuff so don?t mention it to anyone and if you do please don?t mention the source.
Lets? add another factor. Ni and M6 have real different saturation and distortion characteristics. Forgive me, but M6 saturates at about 17,000 gauss and Ni about 5,000 gauss. The 1% distortion levels are at about 14,000 gauss and 4,000 gauss. Now what do you suppose one of the key ingredients is in the determination of primary turns? Walla,
it is the flux density and so as the flux goes down the turns must go up in a direct proportion. The saturation curves look really different on the scope and I am sure they sound really different, like sharp to smooth. Walla, again.
So, where do we go from here? The Ni material is far too expensive for a tube output transformer and the AC input voltage is controlled inversely by the flux density, so M6 is the only acceptable material for a modern day output transformer. Today we cannot purchase Ni material larger than EI75 without committing to large quantity. If we commit to a THD level of 1% the Ni transformer would be 3 times the size of a M6 core and only 12 times the cost, so lets? be practical. Pleeze.
I have tested gapped core (single ended) transformers. The Ni and M6 cores have the same characteristics when gapping the core. Major losses in core efficiency result. That causes a single ended transformer to be about twice the size as a PP. Right! So forget Ni in a SET unless it is low power, low DC current and low input AC voltage.
Where does the Ni core have value? Low input voltage, low power, high inductance, low frequency and they really looks good and sounds good.
EDCOR Electronics now has Ni cores for XSM, WSM and some low power or low voltage transformers, too.
If you have any other information to add please do so. I am always interested in information.
