Flexibility of custom isolation transformers

Why do we custom isolation transformers? Flexibility is the key advantage, among the others. Here we list a few options and actually there are more than meet the eye. 

Above i a multi-tapped primary and a balanced power output. User can connect to either one of the input based on their input primary voltage. User can also select to boost or buck the output voltage if the user connects to a higher or lower tap to achieve the desired output voltage.

Other than input voltage adaptation, and output voltage tuning, custom isolation transformers can have multiple inter-isolated outputs by having separate secondaries with different (or the same) VA to cater for different gears that have different power consumption, and input voltage requirements. Inter-isolated means the secondaries are shielded from interfering from each other rather than affecting each other for quieter operations, on top of being shielded from the primary / incoming mains. 

Above is a super flexible isolation transformer where user can fine tune to 16 combination of voltages, step-up, down, or equal. The step can be 10V-step as what's shown above, or 5V-step, or 20V-step, up to user's requirement. 

Balanced outputs can be tuned too, not just unbalanced outputs. User can have +/- 110V, or +/-120V, or others. Just let us know. 

Other than the above, another example would be to have multiple secondaries with multiple VAs and voltage requirements, connected to several output sockets so that user can connect to source, pre-amplifier, power amplifier, DAC, AV equipment, and etc. Outputs can be balanced or unbalanced, or both. 

Another even more extreme case is, in a single chassis fully built isolation transformer system, internally it can have multiple physically separated isolation transformers, each supplying to a single socket to the external world. This would save space by taking up only 1 rack space than multiple, and yet have the beauty of each equipment connecting to a separate isolation transformer. 

The possibilities are limitless. Take the advantage now and reach out to us in the left panel contact us form.

Hear the unheard!

J&K Audio Design

9/2/2025

Toroid Ultra Isolation Transformers and Toroid Ultra Isolation Power Transformers

Happy 2025 to everyone! 

There aren't nothing much to blog about after many years of research and development of various types of audio signal transformers and power transformers. In order to show that we're still alive and kicking, and most importantly, based on feedback and popular demands for higher and higher power transformers, we proudly introduce Level-3 Toroid Ultra Isolation Transformers, and Level-3 Toroid Ultra Isolation Power Transformers. 

In the previous years, we only focus on manufacturing and perfecting our EI based Level-3 Ultra Isolation Transformers. In the past 2-3 years, we have added new technologies to our Level-3 Ultra Isolation Transformers, such as these below additional / optional enhancements: 

1. Special grounding method, called Ubiquitous Ground (UG), coupled with primary and secondary shield;
2. Ultra Low Impedance (ULI) version for better power delivery and transient response;
3. Ultra Low Noise Design (ULND), by doing the inverse method as audio transformers, where bandwidth is limited between primary and secondary, to filter out those unwanted signal, aka, noises; 
4. Additional Permalloy Shield (APS), if environmental noises, either being aggressor or victim, are crucial. 

EI Level-3 Ultra Isolation Transformers are still the best of the best, but the EI transformers size are prohibitively large when it exceeds 1500VA and we seldom entertain requests to produce larger EI Level-3 Ultra Isolation Transformers. 

With the current trend of more and more high power audio amplifiers being marketed, which was a rare case decades ago, the demand for high power isolation transformers have risen significantly, where the EI Level-3 Ultra Isolation Transformers' limit of 1500VA could no longer be sufficient. In addition to that, international shipping of high transformers are expensive and we need more efficient, smaller size, lighter weight power transformers and isolation transformers for international customers. 

Therefore, the Level-3 Toroid Ultra Isolation Transformers, and Level-3 Toroid Ultra Isolation Power Transformers are born. In nature, toroid transformers are more efficient (lower magnetic flux leakage and better utilization of core), produce less electromagnetic interference (EMI) (due to the donut-shaped core design). 

Available sizes are from:

10VA to 3000VA where the largest 3000VA weights about 20KG with diameter of 250mm and 120mm height. 

Toroid cores transformers are much more efficient than EI core transformers. 3000VA EI would weight over 50KG. The Toroid Level-3 Ultra Isolation Power Transformers and Toroid Level-3 Ultra Isolation Transformers can have the same additional / optional enhancements (UG, ULI, ULND, APS) that are available on the Level-3 EI brothers. 

If power requirement is not high where 1500VA is still sufficient, the Level-3 EI Ultra Isolation Transformers and Level-3 EI Ultra Isolation Power Transformers are still the best, as naturally, EI core transformers have narrower bandwidth compared to Toroid core transformers, and with the way EI are assembled together, enabled us to implement more noise isolation and cancellation techniques. 

Either ways, you can't go wrong with either the EI or Toroid Level-3 Ultra Isolation or Isolation Power Transformers. They're much quieter, lower noise electrically and mechanically, stable, lasting, lower temperature, and many more, than the generic power transformers and isolation transformers out there. 

Reach out to us using the contact form on the left panel or drop us a PM in our FaceBook page if you need more information. 

Hear the unheard.

J&K Audio Design

9/2/2025