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Greetings from J&K at Unesco World Heritage site, Penang, Malaysia!

Thursday, November 20, 2014

Solid State Output Transformer

If you are interested to DIY Nelson Pass's Arch Nemesis or the SIT amplifier with Output Transformers, you've come to the right place. Before we go further,

Passdiy Arch Nemesis
SIT Amplifier (Static Induction Transistor)

SIT Amplifier - L'Amp - part 1
SIT Amplifier - L'Amp - Part 2

The Arch Nemesis or the SIT amplifier can be considered the simplest solid state class A amplifier there is. Even the ACA amplifier (Amp Camp) amplifier is not as simple as this. With SIT transistors behaving like a triode, it carries some of the sonic signature tube-o-philes like. For those that prefer triode sound without the tube hassle, SIT amplifier or the Arch Nemesis are good choices to consider.

The use of output transformer in transistor amplifier can actually be traced back to 1980's where Jean Hiraga wrote about having a simple Mosfet amplifier named Nemesis. There are several methods of coupling for such simplistic amplifiers - RC coupled, DC coupled or transformer coupled and we prefer the latter, transformer coupled SIT Amplifier or Arch Nemesis.
  • RC coupled - R dissipates a lot of heat, and C needs to be huge and therefore high quality capacitors cannot be used.
  • DC coupled - needs bipolar supply and is disastrous if something fails and fries the speakers.
  • Transformer coupled - safest, dissipates least heat, but bandwidth limited.
Worry not! With the properly designed transistor output transformer, the bandwidth issue can be resolved by careful design of output transformers. For a good start, we are offering 2 models of output transformers for Arch Nemesis or SIT amplifier.

  • EI Z11 Level 1, 10W @ 20Hz - U$299/pair
  • EI Z11 Level 2, 10W @ 20Hz - U$599/pair
In actual fact, both the above transformer can be customized to suit other solid state class A amplifiers. Just let us know the details on what is needed. If it is not significantly more complex than what we have above, then the price will be similar.

Both are significant upgrade to the RC coupled class A amplifier, be it Arch Nemesis, SIT amplifier, or any class A solid state transistor amplifier that you care to build!

J&K Audio Design

Wednesday, November 19, 2014

Mains DC Blocker

Good news guys!

Our mains DC blocker has been redesigned for ease of use and better effects! For those that is new to mains DC blocker, please refer to this link below:

We present you mains DC blocker MK2!
  • It is easier to use.
    • Just plug your existing power cord to the inlet and the outlet directly to your gears! 
    • We find that having dedicated unit per device improves the functionality and dynamics!
  • It is more effective.
    • Redesigned circuitry is safer and more effective to remove the DC on the mains.
    • EMI/RFI noise filter is optional - depending on user demand.  
  • Options
    • Audiophile grade plugs and receptacles.
    • Audiophile grade internal components.
Basic mains DC blocker unit starts at U$99 + shipping for a 500W capacity.

Audiophile IEC plug

Pure OFC plug for absolute power transfer

IEC plug cover for protection

This unit plugs directly into the equipment and the power cord plugs into this unit. Simple as that! No more messy extension. Suspension for the unit will make different to the sound too, and what to use (ebony cones, ceramic cones, wood blocks, and etc) will be at user preference. 

J&K Audio Design

Monday, November 17, 2014

Solid State Power Transformers

Although our blog is quiet for the moment, things never stop in the background. Below is a piece of  very high end solid state power transformer in the making. It is a piece of 350VA Level 3 Super Hi-B double C core power transformer.

Even before the core is inserted, it is already over 2.5KG. The drawn wires are using Teflon insulated OFC too, not just any wires. That is not all! There are more than meets the eyes. We haven't even started the shielding, labeling and finishing process.

This unit is not as high end as the Level 4 we did for Jimmy Auw but is not far away in quality. It cannot fit a standard XL size transformer case and therefore has to be framed. Although so, we still ensure it is not far away in terms of build quality and sound quality!

We will share more pictures when it is completed.


Best regards.

We'd like to take this opportunity thank Jimmy Auw, a famous Blogger at APAC region, for ordering a pair of Level 4 Super Hi-B double C core power transformers from us.We appreciate his show of confidence on our products as Jimmy only uses the absolute best on his projects. 

For those that are interested in the details, please check out these 3 excellent articles that Jimmy had written at his blog.

We will write about this transformers ourselves too but it has to be postponed due to the busy schedule we have over here, busy winding and making more quality products.

Best regards.

Friday, November 7, 2014

Solid Wood Amplifier Chassis

Now our custom made amplifiers have the option of choosing solid wood amplifier chassis on top of the full aluminum chassis.

Solid wood adds warmth and liveliness to the end results. Standard plates is aluminum. With some additional charges, it can be upgraded to house 3MM - 5MM high purity copper plates. The holes are CNC milled too.

Enjoy the pictures.We simply love the look of these solid wood amplifier chassis. It brings a touch of humanity to the cold machines we always face. It is more expensive but it is well worth the money.

J&K Audio Design