J&K Audio Design Transformers

Howdy everyone! Happy New Year 2022! Hope everyone is safe, healthy and wealthy! 

A lot had happened, including COVID19 that visited us recently, but we are definitely moving on and kicking, although a bit slowly. OMICRON is still in full swing here and one can never be too careful! 

That said, things are still going on in the background. We've just had some great comments from a customer that just took delivery of his DAC filled with J&K audio coupling transformers and power transformers:

• Level 3 Ultra Isolation Power Transformers (dual mono) for the tube I/V stage and 
• Level 2 Isolation Power Transformers (split bobbin, dedicated transformer for all power rails with a total of 6 transformers) for the DAC digital / receiver stage.
• Level 3 signal coupling transformers, OCC Silver wired, 1+1:1+1 (150+150:150+150)
• Level 3 Hitachi Finemet tube pre output transformers, 10K:600

J&K transformers may not look the best, but they definitely functions extraordinarily, AND MOST IMPORTANLY with full of emotions (that's what music is all about!), heart and feelings.  

Check out the comments he sent to the WhatsApp chat group with a few other audiophile friends: 

Names are removed to protect confidentiality of the owners. Please pardon the language used as it is local rojak style REAL conversation, not fake and paid reviews. J&K do not pay for reviews. We only publish reviews from real paying customers. 

Thank you for all the support all these years. 

Signing out. Take care and stay safe!

J&K Audio Design

23/1/2022 

J&K Ultra Isolation Transformer Testimony

We've received another follow up "glorious" testimony from Steve from SMC Audio. 

Thank you for your kind words and time to write us this testimony! 

Quote:

Hi Ken,

I have been meaning to write you about the final outcome of the custom power amplifiers I built using your 800VA Level 3 Ultra Isolation Power Transformers in silver but I have been so busy I haven’t been able to find the time. I still intend to write something more formal but I thought I’d send you this note for the moment.

It seems to me that you are more tube-oriented, while I have chosen to wrestle with the issues of solid-state design and finding ways (hopefully) of delivering the beautiful musicality of tubes without some of the practical issues. I feel that I’ve made good progress towards that goal and I’ve been able to make a lot of people happy with my amps. These custom amps gave me the opportunity to try some new ideas and to “push the envelope” of performance, and I could not be happier with the results.

A friend asked me “How do they sound?” and I told him that I could not explain because I no longer had any words that were up to the task! And it’s true…these amps went to a whole new level of performance that I’ve never heard from anything previously. I’ll have to come up with a new way to describe what I hear from them. The usual adjectives simply fail to convey the experience of hearing the music these deliver, although I will say that “holistically, organically whole and complete” comes to mind. I’ve never heard any other amps as satisfying as these, and think that your transformers are an important part of that equation.

Thank you again for your hard work in making these a reality.

Best regards,

Steve McCormack

End quote. 

Enjoy the pictures. Man, they look so magnificent!  We're sure it sounds as good as it looks! 

P/S: J&K does not pay for reviews. Therefore you will not see our stuff being published in mags or paid reviewer sites. Paid can be in forms of advertisement fees as well. All are testimonies are from real user that paid real money for them - that speaks the most! 

Till then, take care everyone.

J&K Audio Design 

20/6/2021

J&K Ultra Isolation Power Transformers - review from Steve McCormack

Howdy J&K followers! I hope everyone is doing extremely well and healthy in the COVID19 pandemic situation. 

We've been quite on the postings as life is really tough nowadays, juggling between pandemic, work/operations, and family. Therefore, those that are are less important, will be temporary put on-hold. Let's hope that the pandemic will be over soon and everyone can get back to their normal daily life. 

Meanwhile, we do have a GREAT news to share with everyone here. We have recently provided Steve McCormack from www.SMcAudio.net with our Level 3 Ultra Iso Power Transformers for his high performance solid-state monoblock amplifiers. He wanted the best for his customers and he got the best - a pair of state of the art power transformers made with OCC (Ohno Continuous Cast) Silver wires! 

Those who wished to have a look at the actual post, please hop on to our J&K Facebook page to check it out: https://www.facebook.com/groups/jnkaudiodesign

Quote

Hello friends of J&K Audio Design,

This is Steve McCormack writing from California. Some of you may know me from my work as an audio equipment designer, going back to McCormack Audio and The Mod Squad (long ago!). I have had my own small business for quite a while now, SMc Audio (SMcAudio.net), doing custom upgrade work on my earlier equipment and a few new pieces along the way (like my VRE-1C preamplifier and the AC Nexus power distribution and ground enhancement system). I was fortunate to recently receive a commission to build a new set of monoblock amplifiers for a client who wanted the very best work I could deliver. As part of the project, I started looking for a company that could build a set of power transformers that went well beyond any I had used previously. I am happy to say that this led me to J&K Audio and Mr. Ken Loo, who appeared to have the right sort of understanding of transformer design and the quality goals I was looking for.

Once I had let him know what my requirements were, Ken suggested his Level 3 Ultra Isolation Transformer as the best approach, so that is what we went with (configured for my amplifier, of course). My client wanted the best-possible performance, so I requested that these special parts be wound with high-purity silver wire, and that is what Ken has delivered (see photos below).

I have been building high-performance audio equipment for many years, and have done my best to source the best parts available that contribute to improved performance. I have built a lot of amplifiers and used a lot of custom transformers from well-known suppliers around the world.

Nothing I have worked with previously prepared me for the degree of superiority Ken's transformers have delivered. The sense of “you are there” realism took a major step up, along with the level of dynamic expression and engagement that I value so highly. In addition, these transformers are totally silent mechanically, and of course the degree of isolation from AC line noise is outstanding.

It may be difficult to appreciate how much sonic impact transformers with essentially the same electrical specs can have, but I assure you that the effect is very audible.

I have to thank Ken and the J&K Audio Design team for building such a superior product, and I want to urge the other fans here to consider using these transformers in your systems. From my experience, I would say that when it comes to custom magnetics for audio, Mr. Ken Loo and J&K Audio Design are the right people to work with.

Thanks again for your outstanding work on this project, Ken - it is much appreciated.

End quote

For those that are interested to know more about Steve McCormack and his gears, please head to his website www.SMcAudio.net. 

For those who like to know more about our Level 3 Ultra Isolation Power Transformers, please check out the links below: 

https://jandkaudiodesign.blogspot.com/2017/05/ultra-isolation-power-transformer.html

https://jandkaudiodesign.blogspot.com/2020/09/the-best-power-transformer-for-audio.html

https://jandkaudiodesign.blogspot.com/2016/06/isolation-transformer-bandwidth.html?m=1

https://jandkaudiodesign.blogspot.com/2017/05/ultra-isolation-power-transformer.html

Our Level 3 Ultra Isolation technology can be used in any audio gears, ranging from power transformers for solid state / tube amplifiers, to DAC or CDPs, or anything you can think of that needs power transformers. It can even be used as a standalone isolation transformer, which it was originally intended for. If you want the best of the best power transformer, look no further. 

For bargain hunters, we do have our Level 1 and Level 2 transformers that are very good in performance tooo, and is at a lower price range. Although it is our lower range products, our Level 1 and Level 2 transformers are still better than those general or even audiophile quality transformers.

Try, and you shall see. Warning - there is no turning back after you've tried our Level 3 ultra iso power transformers. They are really that good, period. 

Take care everyone, and stay safe!

J&K Audio Design

19/1/2021

UPDATE

After reading this exciting REAL USER feedback, are you excited to use our power transformers in your designs to reap the benefits not available elsewhere? We are the only one producing this for now and cannot be found elsewhere. 

We are looking for only 1-3 partners or distributors, as phase 1, due to our limited production capability, to use our ultra isolation power transformers in their finished goods. 

There are thousands, if not tens of thousands of audio equipment manufacturers out there. If you want your products to stand our from others, sound better than others, and be the best in the industry, please contact us now to be considered as our 3 sole early adopters. 

We will consider opening for more but it is not decided yet as of now, and may be a few years down the road. Your application of our ultra isolation power transformers can be made known, or classified, your choice. 

Thank you!

J&K Audio Design

6/2/2021

J&K TVC User Feedback

Happy 2019! 

It has been a while folks! You know we've been busy! 

For those who'd like to have more updated news and discussions from us, please follow our Facebook page! 

Below are some very nice pre-amplifier pictures from a customer of ours in USA - using the OPTVC that we've built for him some time ago. He's looking for more transformers for upgrades, and that's why the pictures have measurement tape being shown instead of being a studio-like photos for publishing. 

Here are some details of his OPTVC: 

26K:26K

33 step OPTVC

Pri inductance ~150Hy

Pri DC 10mA 

Potted with turrets 

OFC wires 

Comments from customer:

"Last year I got a TVC from you for a preamp my friend Oliver built for me. I'm liking it a lot. Very nice sound. Very happy with it. "

"Here is a photo you requested of the TVC preamp Oliver built. It is an active preamp with combined volume and output TVC with 33 steps. The TVCOPT are in the back to the left. It uses a type 82 rectifier with 6AX4 TV damper warm up buffer. Shown are 01a preamp tubes. It can also use 112a, 31 or 71a DHT tubes."

Some may ask, what the h*ll is OPTVC? OPTVC = Output Transformer Volume Control - It is TVC that can tolerate primary DC and use as a load for a tube stage. Some details can be found here: 

http://jandkaudiodesign.blogspot.com/2016/10/optvc.html

Enjoy! 

J&K Audio Design
1/26/2019

J&K OCC Silver Input Transformer Review

Nothing is more satisfying than receiving good feedback from our customer(s)! Thank you Kris for your post!

The product in the post is a pair of Level 3 OCC Silver Input transformer, specially made for un-balance to balance conversion.  

Actual paying user review is always more realistic than "paid" reviews on magazines.

Till then, continue to enjoy music!

8/5/2018

J&K Audio Design

J&K DAC Review

J&K Audio Design DAC Review - submitted by customer. 

OCTOdac: Fidelity and Musicality Beyond Sound.

Two years in the making, from design to sourcing and subsequently the final built, the entire journey was a huge learning curve and also one filled with utmost satisfaction. Credits to J&K for bearing and taking the journey with me.

Listening: Round One - First Impression

It was flat and dull!... Seriously! With all the additional caps in the DAC unit, it does sound like a punctured tyre trying hard to complete the journey while waiting to be inflated back in shape. Not forgetting the tubes were NOS dating back to the 30s and 40s.  Well, that was the first impression. It did not take long for the DAC to gradually open up and reveal herself. After warming up probably for about 2 hours, the character of design became more apparent. Clean, dark, transient, deep, wide and warm. If I were to put them into simple words, that would be it.  Sonically,  if there’s such words it would be musical neutral yet analoguely warm. Why I didn’t mention accuracy? That in my humble opinion is subjective to the overall setup, room acoustic and head knowledge of the audiophile. One man’s meat, may be another’s poison. A Concert Grand Piano will definitely sound different from a Full Upright Piano… let’s not go down that dark dark alley of audio apocalypse. For mention’s sake…. The design and backbone of this DAC is capable of processing the difference. Everything falls back on the listener.

Listening: Round Two – Width and Depth

Fast forward one week later, after daily non-stop playback of 10 – 12 hours, the full blossom of the DAC is at full bloom. Sonic control was just enough, not like the army general howling battle cries, but enough to keep the darling at arm’s length. Stage depth and width was and still is, beyond walls. Keeping things in perspective, the speaker fades and the band / orchestra / ensemble takes center stage. Dynamics were fast and attacks were strong yet gentle to the ear. Guitar rifts up and down the frets keeps the listener on the edge of our toes, anticipating the next bar or expressive fingerpicking. Attacks of the Flamenco accompanied by the shoe taps of the tap dancer reverbs across the room.

Listening: Round Three – Instrumentals

Electronic sounds like techno and new age were less defined as this DAC was designed with NOS in mind. Old School sound with a touch of new component technology. The thumb of the techno bass and electronic drum were less engaging. Head bangers will find this very upsetting. Though it raises some hair, it doesn’t thump the heart to a point of cardiac arrest. Moving down the spectrum, Rock, Soul, R&B audiophiles will not find any lacking in this. The depth of the bass, tightness of the drum skin and mood of the R&B and Soul are felt across the spectrum. Nothing is short changed during playback. Going further down the stream to acoustic instruments is where this DAC shines! Though only decoding at 20-bits, no details are spared. Starting with the Quattro bass, each slap, slide, pop, bend and vibrato is clearly audible. Brass instruments are bright and zingy. Woodwind blows mellow and sweet. Strings are majestic and swift, each pull of the bow is well defined and expressive. It truly takes a lot out from a DAC to realistically reproduce the sound of a live quartet or orchestra performing in front of the listener. I would say OCTOdac holds up pretty well. Of course system matching and room acoustic also comes into play and both are equally important.

Listening – Round Four (Vocals)

The separation job done by the DAC was superb! Be it in a choir, solo or acapella, the vocals are spot on. Emotions are positively passed on to the listener. Vocal expressions are represented in a way that will keep you anticipating on what will come next. Layers of sound are clearly defined. Vocals lean toward the neutral side. Not excessively warm, neither is it freezing cold. Dim the lights, sit back and crank up the volume. Indeed a hair-raising experience, bordering the fine line of being horrifically silent. Probably Chucky lurking round the corner of the room.

Design

The OCTOdac was fully custom designed with flexibility and future upgrades in mind. The Processing (DAC) Module is truly modular and hot swappable. In the event I would like to have a more vocal centric sound, I can simply build another DAC and swap with my current PCM1702. Satisfying my incurable itch for symmetry, the GainStage was build and design to match my current monobloc amplifier.

DAC configuration & description

Processing (DAC) Stage

Inputs: Fully dedicated S/PDIF and Digital Coaxial.

Output: Single-ended (RCA) analogue outputs.

Convertor: Dual Mono BurrBrown PCM1702 20-bit

Digital Power Trans:  EI - Z11 (Level 2)

Analogue Power Trans: Super Hi-B Dual Core (Level 3)

Gain Stage (monobloc units)

Tube Compliments: 6J5 (driver) , RGN1064 / #1805 (rectifier).

Super Hi-B Dual Core Tube B+ Power Supply

Tube Output Trans: Western Electric Core 15K – 600

Tube B+ Choke: Western Electric Core

Conclusion

The OCTOdac filled the missing piece in my audiophile quest. Truly a bang for buck, value for money and fully customized piece of gem. It doesn’t just bring you music, it carries along with it the joy and emotions of sound. Adequately defining the true meaning of Fidelity and Musicality Beyond Sound.

811 Output Transformer Review

Another user review of J&K Output Transformer - this time is for 811 tube. 

Advertisement time! 

1. We customize low to very high end, low to very high power transformers.
2. We accept individual retail and corporate orders.
3. We customize amplifiers, DACs, power conditioners and various audio gadgets (depending on our free time and available slot).
4. Email to order! Lead time is 4-6 weeks. To avoid the long wait, order early! 

Just a side note - is HIFI enthusiasts so into spending for HIFI that they cannot get a phone with better camera? (Just kidding!).

Here goes another user feedback in USA:

The sound is awesome, I have monblocks, so I can do A/A testing. I changed on one amp, and my wife me tested some mono recordings..

with J&K it was like a thick veil got lifted, the musical details increased on all spectrum of frequencies, it was just amazing..

Now to change my next amp in 2 weeks when I am back from my travels..

Attached is a picture of the new output transformer in a separate chassis on the 2nd shelf

cheers

Schematic shown is not for commercial purposes.

We will try to put in more post this year... we hope. 

J&K Audio Design
31/1/2018 

Transformer upgrades with J&K ultra isolation transformer

Another great testimonial from our customer using our J&K Ultra Isolation Transformer - a real paying user feedback, rather than bogus paid reviews on blogs or magazines. 

Rich has been replacing all his transformers on his existing HIFI equipment with our Ultra Isolation Transformers. 

* Replace existing transformer with ultra isolation transformer
* Separating critical power rails to separate ultra isolation transformer
* Upgrading super critical power rails with OCC made ultra isolation transformers
* and many more... 

Without further ado, here goes the feedback from Rich. This is just the tip of the iceberg on the upgrades he had done to his HIFI and Home Theater gears. 

Auralic Vega DAC upgraded power supply with J& K Discrete Ultra ISO transformers replacing original toroid. Now front-ended by two stages of balanced Ultra ISO transformers for each of the three  secondaries in the Vega. Since upgrading the Crystek clock to the Pulsar, the lowered noise can really show what the clock can do for cleaning up transients, illuminating blur, spaciality/imaging and a very natural listening experience. J&K Ultra Transformers mounted in the silver enclosures on top of the Vega.
Also using two Ultra ISO stages for both the Uptone Audio USB Repeater and Antipodes Music Server.

Fantastic!

Rich

Main 240VAC Distribution Hub for front-end components

- Preamp
- DAC
- Music Server
- USB Regenerator
- Home Theater Processor

Fused 240VAC mains input into overbuilt J&K Audio-inspired DC blocker with fused 240VAC feeds to six external Ultra ISO balanced secondary Transformers for source components. Voltage (240V) display on front panel.
500W OCC wound 120VAC balanced secondary Ultra to three feeds for separate OCC wound Ultras for front-end analog circuits.
All power feeds to the system are now balanced.

Apologies for not posting that often. We are super busy with orders. 

J&K Audio Design

31/1/2018

GM70 Amplifier Review

GM70 tube amplifier review (a short one).

Domnic uses full set of transformers from J&K Audio Design - the GM70 output transformer, separate power transformer for B+ and filament transformers. 

Enjoy the pictures - very nicely done!

Short and sweet comments from Domnic!

The hum & hissing are not related to the transformers but the design of the amplifier. After several emails between Domnic and us, this issue is fixed by adding some additional circuit to the amplifier. The amplifier is as quiet as the deep wide universe now, and he's a very happy camper!

Some GM70 amplifier internal picture for those more technical minded. A lot of audiophile components are used, such as Mundorf electrolytic capacitors, Jensen PIO coupling capacitors, Kiwame carbon composition resistors and of course, full set of J&K transformers.

Again, this is as honest as it can be - review from real user! No alteration of the customer posts have been made.

J&K Audio Design
11/3/2017

J&K Transformers Review

J&K Transformers Review

Nothing beats hearing from a happy customer using J&K transformers! In addition, a real paying user review is 100x better than a paid review in a magazine. There is no conflict of interest, and the content is genuine, albeit it is not professionally or beautifully crafted by a writer. So here goes nothing, a J&K output transformer review.

Frank is from Germany and he was looking for a pair of very high end single ended output transformers for his tube amplifier using 300B XLS. He'd like to upgrade the output transformer on his ASL 1005 to something significantly better. Frank knows what he wants from the start - he immediately pointed to our ALIS-5SE Paragon Nanocrystalline Double C core output transformer, which is a Level 3 transformer. 

For more details of this OPT, you can refer to link below:
ALIS-5SE Paragon NanoCrystalline Double C Core

No pictures, no truth - here you go, some pics taken by Frank on his ASL 1005 300B amplifier.

A print-screen of what Frank has written after he'd tried our Level 3 Output Transformer on his ASL amplifier - in short, blown away! We've gotten his permission to post this of course. Frank's last name has been removed to protect his privacy. 

// Quote:

Hi Jolin,

the transformers are installed now, they sound really great. Everything is like it should, sounds really natural, 3D audio in perfection. 

The ends are more expanded, in particular the heights, absolutely no compression the sound is freed in all directions. The pictures of my amp you find attached. 

My amp was a Antique Sound Lab AQ-1005 MKII, but I’ve changed nearly everything (mains transformer and choke of the power supply, preamp is now 

Aikido cascode with 6SN7, only the casing is the same but with an additional ground floor for the chokes. The weight of teh amp is about 15 kg more than before.

Thank you very much for this wonderful pieces of technology.

Best Regards

Frank

// End quote.

Many thanks to Frank for voluntarily sending us his review! We appreciate it very much. We'd like to encourage others to send it too, so that more people can get to read their comments, and discover new path to audio nirvana.

Hope you enjoy the short, sweet and simple review of J&K products. 

Thank you and see you again!


Hear the unheard! Sail the uncharted! 
Long live custom made audio!

J&K Audio Design
9/16/2017

J&K Products Review

Greetings everyone! Yes, we're still alive, although we have been quiet on our side.

Apologies for not being able to post as frequent as before. Time is really running short at our hands. Lead time is getting longer as our custom made department is fully, well, overloaded with orders from everyone.

That helped us to put bread and butter on the table for some of our technicians, support workers, and suppliers. Thank you very much, guys! Your support is very, very appreciated.



Today, we'd like to share a short review from our supporter in USA! He'd purchased quite a number of ultra isolation power transformers to replace the transformers inside his existing equipment, as well as the ultra isolation transformers as external use for power filtration.

Here's Rich's review on our ultra isolation transformer below in his home theater! Yes, ultra isolation transformers are not just for audio (HIFI), but can be for home theater too!

We're very happy to hear that he's enjoying our ultra isolation transformers! And thank you (Rich) for allowing us to share your write up.

Some background reading for new readers, if they're unaware of what they are all about:
http://jandkaudiodesign.blogspot.my/2016/06/isolation-transformer-bandwidth.html
http://jandkaudiodesign.blogspot.my/2017/05/ultra-isolation-power-transformer.html

You can order transformers in such a way from us (I know, it's a lot of options but it is all worth it!)
* power transformers with electrostatic shield (standard in market)
* ultra isolated power transformers or pure ultra isolation transformers (size is almost same as transformers 2x the rating)
* upgrade OCC (Ohno Continuous Cast wires)
* upgrade from EI to C or double C cores 
* core upsize (operate at lower flux density, size will be much, much larger!)
* bare with frame, or upgrade to end bells, or potted in casing (recommended for low noise operation)

Why all these options? All for better sound of course! And it does matter.

PS: We've users that paired our transformers OCC power cords and they find huge improvements. That's why we are offering OCC in our power transformers, chokes and isolation transformers now instead of just purely for the audio transformers such as output transformers, input transformers, TVC and interstage transformers. Instead of the 1-2 meter of OCC at the power cord, now you get hundreds of meters of OCC in the power transformers. Imagine the improvement you would get!

J&K Audio Design
8/13/2017

J&K Isolation Transformer in High End Setup

We've recently flown a unit of fully built high end J&K Isolation Transformer to USA. The user is kind enough to allow us to share his setup pictures with our followers. J&K Isolation Transformer is used to power up 2 stereo Nord One SE UP NC500DM amplifiers. 

It is such a lovely setup. It gives us a sense of Zen and peacefulness when we looked at his setup. Well done, sir! J&K Isolation Transformer's silver fascia matches will with the color scheme of his whole setup too!

Speakers used in the setup are Analysis Audio's flagship, Amphitryon:

• http://www.analysisaudio.com/Amphitryon.php

The speakers were purchased without a crossover. The owner employs active digital crossovers and and DSP with his preamp (pre-processor), Trinnov's flagship, Amethyst:

• http://www.trinnov.com/products/hi-fi/amethyst/introduction-amethyst/

The speakers are bi-amplified (2 stereo amplifiers), using Nord Acoustics - Nord One SE UP NC500DM Stereo Silver:

• https://www.nordacoustics.co.uk/product-page/nord-one-se-up-nc500dm-stereo-silver

Each amp uses a pair of Hypex Ncore NC500 modules.

For vinyl, he uses vintage Micro Seiki RX-3300, with SAEC arm. Cartridge is Transfiguration Proteus. He uses Audio Note SFZ step up transformer and Audio Note phono:

• http://www.audionote.co.jp/en/products/pre_amplifier/ge-1.html

Enjoy the pictures!

Tips:
* EI isotrans - better for front end, low power amplifiers, preamplifiers, sources
* Toroid isotrans - better for medium-high power gears

J&K Audio Design
5/12/2017