Planning a DIY Balanced Isolation Transformer console

[Hari Iyer]

After a brief discussion with FM Prem, i started reading a couple of articles about isolation tranformer (IT) and balanced isolation tranformer (BIT) and thought of DIY one using spare transformers lying with me from uncompleted projects.

I used a 0-12v transformer back to back and created a isolation transformer for my CD player and noticed a sure change in sound stage for the better. I visited a couple of sites and learnt more about isolation and discovered that the setup sound great if all the digital and analogure sources are isolated from each other. Further reading, gave me thoughts about balanced isolation transformer where all leakage currents can be grounded to earth by using a properly designed PI filter with filters. Hence i will be havving now a balanced isolation transformer for my tube power amplifier and also a separate balanced isolated transformer for my analogue (Vinyls, Tapes) source and digital (CD Player, DAC) source.

I had tried a small prototype with the above scheme last week with tremendous sound stage with the balanced isolated transformer for my tube amp. The analogue and digital source were just isolated and not balanced. But due to lack of current and right sizing these trasformer caused over heating and magnetic hysterisis noise and hum and needed to be disconnected. I have ordered 4 pairs of right sized transformer for my analogue and digital sources which will be center tapped transformers connected back to back along with the PI filter which will deliver around 70 watts in the floating primary. The actual requirement is around 45 watts which gives me a decent headroom. The tube amplifer float primary requires around 80 watts and my balanced power transformer gives around 110 watts which is okay. Hope to complete this project by this weekend.

Will post a schematic of this console for benefit of DIY community.

Inspiration for this project comes from the below links,

https://www.diy-audio-guide.com/isolation-transformer.html
http://www.equitech.com/articles/enigma.html

 

[prem]

For those with no DIY skills can buy from Plixir in Singapore. I used to have one from BPT long back.

For balanced, use the best possible quality transformers.

 

[jls001]

Following......

Hari, does step down transformer in a way works as isolation transformer as well ? 220 volts to 110 volts for US components.

Input and output voltages need to be same in isolation transformer. If you have two 220/110 transformers, connect the 110 terminals and you effectively have 220 in and 220 out. You'll even have double galvanic isolation

Do take care of power ratings, though.

 

[Hari Iyer]

For those with no DIY skills can buy from Plixir in Singapore. I used to have one from BPT long back.

For balanced, use the best possible quality transformers.

Unless you are very sure about what you are doing this should not be attempted as this involves playing with live voltages from mains, any mis interpretation could give you an electric shock and could prove fatal imo.

 

[Hari Iyer]

Attached schematic A SB fuse, 5 A will be added to the Line hot point. I may connect chassis of all source devices to this common earth as all my source are 2 pin socket.

 

[mpw]

Unless you are very sure about what you are doing this should not be attempted as this involves playing with live voltages from mains, any mis interpretation could give you an electric shock and could prove fatal imo.

U be careful too. .

Please cross check what you intend to do with a professional...

 

[prem]

http://ep2000.com/support/library/
You can read all the white papers here in this link. A different patented approach to clean power. I use their products.

 

[Hari Iyer]

Now I am using the DIY isolation transformer for more than 2 weeks with no issues. I have connected my DAC, CD Player, Tape deck, phono preamp and tube amplifier to them. Check out images.

 

[Selvin]

How the result / improvement in sound quality?

 

[Hari Iyer]

How the result / improvement in sound quality?

It's one of the best or top mods in my set up. It's as good as a major source upgrade. The harshness completely disappears and instruments and vocal clarity/ tone is astonishing. It's a must do for serious listeners imo.

 

[acpadhi]

Now I am using the DIY isolation transformer for more than 2 weeks with no issues. I have connected my DAC, CD Player, Tape deck, phono preamp and tube amplifier to them. Check out images.

Cool, would love to have a few more details if you can share on the inside, the type of transformers etc, may be share the DIY details.
One thing that concerns me in this arrangement is the generation loss across the transformers(Trafo efficiency etc). Also, heat generated from these multiple transformers arrangement could be another concern if I am right.

 

[Hari Iyer]

Cool, would love to have a few more details if you can share on the inside, the type of transformers etc, may be share the DIY details.
One thing that concerns me in this arrangement is the generation loss across the transformers(Trafo efficiency etc). Also, heat generated from these multiple transformers arrangement could be another concern if I am right.

Yes, you are right. Transformer core looses are high. Heat generation is an issue. But if you size your transformer properly then it will not overload. They key is to get the exact load in watts and double or triple your transformer rating for reducing heat issues. Grounding of all transformer can reduce some noise. The box needs good air circulation / ventilation due to the heat.

I have used aix of toroidal and EI transformers. Most of the transformer are from incomplete DIY projects.