Order by emailing us at jnkaudiodesign@gmail.com

Saturday, August 30, 2014

Price List

J&K price list for your reference - not all our products are listed. If you do not find what you want, just shoot us an email.

J&K Audio Design
30 Aug 2014

We may make changes to specifications and product descriptions at any time, without notice. The information here is subject to change without notice. Do not finalize a design with this information. The products described in this document may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Contact us to obtain the latest specifications and before placing your product order.

*Other names and brands may be claimed as the property of others.
Copyright © 2014-15, Intel Corporation. All rights reserved.

Thursday, August 28, 2014

Cobalt Output Transformers

We thought that this was the best we could do - the largest Amorhpous double C Core output transformer - giant C core output transformers.

We were wrong!

We're now rolling out Level 2 Cobalt based Amorphous C cores output transformers! Now that is something exotic and special. Cobalt is a rare earth mineral and is highly sought after. They have the sound of their own too that cannot be found using other cores.

Cobalt iron for transformers - this is an alloy that contains Cobalt 35. It is expensive and unusual to be used as output transformers. It has advantages of having very high permeability yet high handling power with saturation limit with a Bmax of ~24000. This equals more sensitivity to changes (micro-details), resulting to refine sound, and with ample reserve to handle high flux (high signal/power). Take a look at the table of its' magnetic properties.

We do not have to say more about Cobalt based output transformers. Just Google for it yourselves.

Cobalt based C Cores

Cobalt C Cores

Cobalt Output Transformers

Magnetic Properties

Notice the Cobalt steel properties? It has highest DC saturation limit and maximum AC operating flux among all the other materials! With reasonable Permeability that is sufficient for audio range operation, it is one of the best material for building output transformers!

Now, scroll to the bottom and fill in the form to order yourself a pair (or a couple of pairs) of Cobalt transformers before they're gone. This rare earth mineral is getting scarce everyday. We do not know when it will run out as there are very little stock left of such high grade materials.
J&K Audio Design
28 August 2014

Wednesday, August 27, 2014

Transformer Case

These are the transformer cases that we are using for some of our potted transformers. Since a lot of people asked about what we use, we might as well publish it here to save all the attaching work. :)

3 sizes:

  1. 80 x 80 x 90 (H) mm, mounting hole 60 x 60 mm, 4m thread, window 46 x 46mm, 1mm thickness top, 1.8mm bottom plate, for EI76, for single C cores - U$33/pc
  2. 105 x 105 x 105 (H) mm, mounting hole 83 x 83 mm, 4mm thread, window 67 x 67mm, 1mm thickness, 1.8mm bottom plate, for EI96, for single and double C cores - U$35/pc
  3. 122 x 122 x 130 (H) mm, mounting hole 96 x 9 mm, 4mm thread, window 73 x 73mm, 1.2mm thickness, 1.8mm bottom plate, for EI114, for double C cores - U$D38/pc

  • Internal dimension is external - ~3mm.
  • Special prices if is used with our transformers. 

J&K Audio Design
27 Aug 2014

Power Amplifier

This is a customer's power amplifier using our 500VA Z11 power transformers.

J&K Audio Design
27 August 2014

Tuesday, August 19, 2014

3K Single Ended Output Transformer

3K Single Ended Output Transformer In Circuit Measurement - Level 3 - Amorphous Double C Core - Made for KT88 / KT90 / EL156.

Single Ended Pentode
 Above are in-circuit actual operating measurement.
KT88 Pentode Mode.
2dB per column for Y-axis

Single Ended Triode
Above are in-circuit actual operating measurement.
KT88 Triode Mode
2dB per column for Y-axis

Frequency response:
* 20Hz(-1.71dB)—1KHz(0db)—20KHz(0.18dB) (Pentode mode)
* 20Hz(-0.16dB) (Triode mode)
UL: 40%
Primary Impedance: 3K
Primary DCR :135Ω(B-P,28℃),
Secondary DCR: 8 Ohm @ 0.62 Ohm
Primary Inductance:26H (measured at 140mA,20Hz,5Vrms)
Max Pri DC:240mA (recommended 150mA)
* DCR 2% (0.2 Ohm)
* Primary Inductance 5% (1H)

J&K Audio Design