toroidal transformer or EI frame transformer for HARTKE A70

[phil-am]

Hi Guys,

Just wondering if you encountered problems with your amp regarding power supply.

Mine is HARTKE A70, it just went dead.

I guess the transformer blew off as it has no more power.

I asked for the help of our local luthier/amp repair guy here in our place and he replaced the toroids with a EI frame transformer.

Is EI transformer much better that the toroids?

I’ve done some research and the article says that EI is much better than the toroids except for the issue of strong magnetic field that would induce hum in the audio signal.

So far, I’m not hearing some hum in my amp, lol.

Btw here’s the article SoundStage! Max dB - The High-End Mythology of the Toroidal Power Transformer (07/1998)

Feel free to add some comments here, thanks in advance

 

[agedhorse]

A properly designed transformer of either type will offer the same performance. This comparison is full of mythology based on the audiophile marketing world, these folks specialize in separating you from your hard earned money by any means possible IME.

One BIG advantage of toroids is the ability to achieve higher power density. With the right core and geometry, very high flux densities can be supported. Noise is a very real issue with toroids, the winding pattern and coverage must be carefully designed and controlled in production to avoid the leakage lobes that often plague toroids.

 

[BassmanPaul]

“I guess” is not a good answer about a problem with an amplifier. Many perfectly good transformers have been replaced because of those two words.

Take your amp to a tech and see what he diagnoses as the problem. Take the guesswork out of the equation.

 

[SirMjac28]

A properly designed transformer of either type will offer the same performance. This comparison is full of mythology based on the audiophile marketing world, these folks specialize in separating you from your hard earned money by any means possible IME.

One BIG advantage of toroids is the ability to achieve higher power density. With the right core and geometry, very high flux densities can be supported. Noise is a very real issue with toroids, the winding pattern and coverage must be carefully designed and controlled in production to avoid the leakage lobes that often plague toroids.

Everything you just said went way over my head but man was it beautiful.

 

[phil-am]

aright guys, ill follow all your advice..thanks

 

[beans-on-toast]

I'm confused. Did your amp break and it was repaired using a different transformer and not it is working again? You are simply questioning which type of transformer is best?

There are tradeoffs between toroidal and EI designs. Size and weight sometimes dictate what is used. If the EI has the same or better voltage and current specs, and fits in the amp, half the battle is won. There are potential other issues though related to noise. If the new transformer does not meet the old electrical specs there could be a problem.

One test of a power transformer is how it performs when pushed hard. If you find that the amp now distorts at high volume levels, it is not performing as well as the old one. If the amp is working again and sounds good, don't worry about it.

 

[phil-am]

I'm confused. Did your amp break and it was repaired using a different transformer and not it is working again? You are simply questioning which type of transformer is best?

There are tradeoffs between toroidal and EI designs. Size and weight sometimes dictate what is used. If the EI has the same or better voltage and current specs, and fits in the amp, half the battle is won. There are potential other issues though related to noise. If the new transformer does not meet the old electrical specs there could be a problem.

One test of a power transformer is how it performs when pushed hard. If you find that the amp now distorts at high volume levels, it is not performing as well as the old one. If the amp is working again and sounds good, don't worry about it.

sorry for the confusion..yeah my amp break and the power transformer was changed from toroidal to EI..currently its now working although I haven't pushed my amp hard..thanks for the advise, ill try to see if the amp is working normal at high volume level..