We can make anything that you can dream of. Just shoot us an email at jnkaudiodesign@gmail.com or fill in the form below. Greetings from Penang, Malaysia!

Saturday, January 17, 2015

Amplifier Hum

Let us share a story related to amplifier hum with you guys. We think that it is worth reading as it may be applicable to some of the new DIY guys.

Recently, there's a guy that ordered a full set of Level 3 transformers from us. That includes - 1 Level 3 power transformer with Super Hi-B double C core, 2 Nanocrystalline double C choke, and a pair of Nanocrystalline output transformer.

According to him, his previous similar project ended up being too noisy and has pretty serious humming although he is using quite decent transformers from some company that we should not mention here. He is hoping that by getting high quality transformers from us, it will help to resolve all his problems.

We have heard this comment for many times and we always replied the same message to them, that we will write below. Since it affects a lot of the newbies, we decided to publish an article here so that everyone is clear on this topic.

A good set of transformers will no doubt bring you better signal to noise ratio, low hum, darker background, wider bandwidth, better THD and all those goodies, but, if your design look like these:

Amplifier layout that looks like Ampang Yong Tau Fu

Design that looks like Penang Char Koay Teow

Wiring that looks like Singapore Char Bee Hoon

A good set of transformers will only give you the edge and advantage to be at a higher ground than other low quality transformers, but if the design, ground, wiring, layout and all those important aspects of amplifier building are not followed, the end results are not going to delight you very much.

One thing that new DIY guys can do is to look at how others do the layout design on the WWW, and LEARN from them. There are thousands of nicely laid out design in the market nowadays. Their level of workmanship is simply stunning. We admit, we cannot come even close to some of the masters out there too but we'd always exchange photos internally when we come across those excellent designs out there and keep polishing our layout skills.

Layout is an art!

On schematic, or circuit design wise, beware of what you want to copy or clone. We've repaired many branded amplifiers and clones. There are a lot of "flawed" or purposely modified famous designs out there to mislead someone that by cloning these famous design, they get close to the sound of the OEM equipment. We found that a lot of those schematics floating online are NOT the actual design someone purchases on the shelf. They are mislabeled, values are changed, designs are changed purposely for you know what reasons. So, unless you know what you are copying, go ask someone that knows before you do something. If you are lucky, it works perfectly or substandard-ly. If not, kaboom!

Good luck in your DIY journey! Questions and discussions welcomed even if you are not purchasing from us. Audio is not just our business but our hobby too. Just use the contact us box in our blog to reach us.

P/S: No pun intended on using food pictures as references. It is just an analogy. These are no doubt great hawker food in South East Asia.

J&K Audio Design

Wednesday, January 14, 2015

Transformer Core Grades

We usually provide quotations to our customers with different transformer core grades. For expert users, they will know what those transformer core grades means and what the impacts are to the results or sound. For those that are rather new to DIY or to transformers, they might find it difficult to understand.

We were thinking of writing an article to educate the users on the benefits of different transformer cores and that is the reason for the birth of this article. It just so happens that we previously came across 2 excellently written articles by Eddie Vaughn that discuss the pros and cons of different transformer cores. This saves us a lot of effort to reinvent the wheel and direct our efforts to keep up with the production schedules.

Please download these 2 articles and enjoy the read! We're not sure how long will these articles be kept in the vault. So, please do so before it is gone.

SE vs Push Pull Amplifier Part 1

SE versus Push Pull Amplifier Part 2

Part 1 focuses more on tube amplifier design and differences between different topologies or design circuits. Part 2 touches the "deep, dark secrets of output transformers", where most people are interested to know! It talks about various core types (EI, Toroid, C cores), SE and Push Pull output transformers, different core materials and many other details on transformer design.

It is YOUR lost if you do not download and read it. After you read it, you will gain better understanding of what the fuss is all about on different transformer core grades, types and design. You will appreciate more what transformer cores or grades that are used in your power transformers, chokes / inductors, inter-stage transformers and output transformers. The transformer myth is debunked in a bird's eye view.

J&K Audio Design

Sunday, January 11, 2015

Email Response

Dear customers,

If you do not hear from us after sending us emails or replies, kindly resend or remind us again.

We found that our replies sometimes did not get sent although the replies had gone to the outbox and showed as sent.

Apologies for the inconveniences.

Thank you!

Wednesday, January 7, 2015

Audio Note Conquest Upgrade

An Audio Note Conquest 300B PSE power amplifier came in for repair and upgrade. Smoke rose from this unit when it was in operation. Upon inspection, the cathode bypass capacitor was blown, together with the 300B tube where the filament was broken and the spring came loose. It is either the defective 300B tube damaged the amplifier or vice versa.

Since this unit has been used for quite some time, the owner agreed to recap all the electrolytic capacitors. We checked all the capacitors and found that some had already leaked and some are busted, including some resistors that showed sign of overheating.

Some mounting that we do not like was also modified - electrolytic capacitors being placed directly beside a vacuum tube. Such capacitors will be operating at high temperature and will have shortened lifespan.

The stock ceramic tube sockets were of low quality types and were replaced with Teflon or high grade ceramic with gold plated copper pins. The new sockets provides a much better contact, mechanically stable, and less resonant compared to the stock sockets. There are several other changes and modifications that we do not mention here but is beneficial to the sound or build of the Audio Note Conquest amplifier.

The owner wanted to upgrade the EI output transformer to J&K Level 3 Nanocrystalline Output Transformer too but unfortunately the cavity was too small to fit the Level 3 OPT. The owner will be saving that for a future new tube amplifier.

Audio Note Conquest

Teflon tube sockets with gold plated copper pins

Tube rectification board before modification

Top view after completing the modifications - note all the new high quality tube sockets.

All the Rubycon capacitors are changed to Nichicon

The low quality rectifier tube socket

Modifications made to provide 5X4G compatibility. Capacitors are upgraded too.

Comparison of high quality versus low quality tube sockets.

Worn capacitors and tube sockets

Some doctor scribblings on what to change.

Side view of the high quality Teflon 300B tube sockets

Teflon 300B tube sockets

Nichicon Capacitors for B+
It was found that some of the components are not matching between the 2 mono-blocks. It might have been some poor repair jobs done previously. The soldering job was badly done to as you can see from the pictures.

The Audio Note Conquest will go through several checks before being powered on. After that, it will go through some burn-in test before being passed back to the original owner.

Due to the busy schedule we have, we shall be limiting our modification and repair services to focus on our core business. Apologies for not taking in all work from now onwards. This may be our last repair and modifications service job unless there are some that are really worth our attention for analysis or study purposes.

J&K Audio Design

Sunday, January 4, 2015

Transformer Upgrade

Quote of the day from J&K Audio Design:

If power cables make sense to your system, high quality power transformers and power chokes will make even MORE sense since they have hundreds and thousands meters of wires inside!
On the other hand, if speaker cables brings improvement to your system, high quality output transformers will bring even MORE improvement. Same rules apply.
You will not fully realize the potential of your system until you have used dedicated audio grade transformers from J&K Audio Design. Period. 

J&K Audio Design