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Friday, February 28, 2014

Transformer Cases


These are Western Electric style transformer cases for housing the transformers. They are made of 1mm steel plates with WE style grey paint. There are 4 sizes for different transformer sizes. It comes in a set - the top cover and the base. This matches perfectly with our Value Line - Double or Quad C Core Transformers.

Below are the external dimensions. For internal dimensions, please deduct 1mm.

  • Size 0 - base 110mm x 110mm, height 135mm. Mounting hole: 74mm x 62mm - U$36/pc
  • Size 1 - base 110mm x 100mm, height 130mm. Mounting hole: 75mm x 65mm - U$32/pc
  • Size 2 - base 105mm x   90mm, height 115mm. Mounting hole: 67mm x 63mm - U$28/pc
  • Size 3 - base   95mm x   80mm, height 105mm. Mounting hole: 55mm x 54mm - U$24/pc
  • Size 4 - base   65mm x   65mm, height   90mm. Mounting hole: 50mm x 50mm - U$20/pc
Pictures for you to enjoy:






J&K Audio Design
28 FEB 2014

Product Lists  

Level 0

Level 3: depends on type, size and complexity. Email us for details.
Iso-trans: link 1, link 2
* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  
* Our product lines are always improving and increasing. If you do not see what you want, contact us!  
* Please email for volume discounts, distributor and OEM pricing.

Thursday, February 27, 2014

Quad C Core Output Transformer



Value Line Output Transformers (last update 1/1/2016)
Preface

We are lucky to secure a batch of limited quantity vintage British made C cores (silicon steel, amorphous steel and amorphous nickel-steel alloy C cores). Some of them are NOS and some of them are pulls. It might look a bit worn or rusty due to age but it still functions perfectly. We have taken this into consideration of the price (cheaper) as compared to a full price (especially amorphous) C core that is sky high in price in the market. Please do not order the amorphous C core transformer if you cannot tolerate this. 

Amorphous cores are meant for medium to high frequency use. Amorphous cores (worse if is or added nickel) are easily saturated and therefore the low frequency response will not be as great as the Z11 or Z6 cores. Due to such magnetic properties, designing such audio transformers requires extreme care, and larger cores are required to achieve good low frequency response.

In order to overcome this limitation, the best way is to increase the core size, and therefore dual C core and quad C core are called for in TRUE high fidelity design that excels both in extended refined high frequencies, dense and warm mids and deep impactful bass. 



Why do we need a quad core one might ask? It increases the core volume by 400% (4 cores!) to give more headroom. With the 4 cores covering N-S-E-W of the bobbin, it is actually fully utilizing instead of wasting the flux produced by the coil for increased efficiency and better sound! Imagine retrieving back of the original signal/energy lost back to your system. 


In addition, we prefer the vintage British made C core too, like many of the excellently made British HIFI gears. Nowadays such high quality C cores are hard to find and expensive to source. We will not dig further into the advantages of amorphous core. You can read more of them in the internet.
I’m keeping a few pairs for myself for various circuits before it runs out, are you? 

Lead time is around 2~4 weeks. Customization services for different applications, circuit topology, air-gap, configuration or different tubes are available.

Quad Core
QCAMOPT-L01---(3.5K OPT for 300B)                    - $449/matched pair
QCFEIP-S01-------(1:5.8 input/pre-out)                  - $329/matched pair
QCAMOPT-M01---(2.5K/5K OPT for 2A3/45)           - $209/matched pair (no longer have stock, email to check for availability)
(limited standard units left, cannot offer customization for QCAMOPT-M01 size, 2.5K/5K OPT can still be done using the QCAMOPT-L01 cores)

Double Core
DCAMOPT-X01---(8K/16K OPT for 211/845)           - $659/matched pair
DCAMOPT-L01---(3.5K OPT for 300B)                      - $329/matched pair
DCAMIT-L01------(1:2.25 interstage for 211/845)     - $329/matched pair
DCAMC-M01------(8H/300mA choke)                        - $129/piece

Single Core
SCAMOPT-M01--- 3.5K: 8 Ohm - $269/matched pair

SCAMOPT-M02--- 6.6K: 8 Ohm - $269/matched pair

QC – quad core, DC – dual core, AM – amorphous, FE - ferrous
NOTE: please email us if you need other specifications.

Looking for transformer casing -> Matching Transformer Cases

Transformer Details

Amorphous Quad C Core Output Transformers (nickel-steel alloy) – QCAMOPT-L01
This is made using 8 pieces of C-core per transformer, having 16 pieces altogether for a pair of high end amorphous quad C core nickel steel alloy output transformer for tube amplifier. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.

  • Available types: single ended and push pull
  • Primary impedance: 3.5K (standard), other impedances per request.
  • Primary inductance: 35H @ 100Hz,
  • Primary current: 150mA maximum
  • Primary DCR: 98 Ohm, Secondary DCR: 0.45 Ohm (@ 8 Ohm tap)
  • Leakage inductance: 6mH, leakage capacitance: 14nF
  • Frequency response: 30Hz – 30kHz
  • Weight: 2.5KG per piece
  • Size: 95mm x 80mm x 105mm
  • 3.5K / 4-8-16 Ohm
Amorphous Quad C Core Output Transformers (nickel steel alloy) – QCAMOPT-M01
This is made using 8 pieces of C-core per transformer, having 16 pieces altogether for a pair of high end amorphous quad C core nickel steel alloy output transformer for tube amplifier. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.


(limited standard units left, cannot offer customization for QCAMOPT-M01 size, 2.5K/5K OPT can still be done using the QCAMOPT-L01 cores)
  • Available types: single ended and push pull
  • Primary impedance: 2.5K: 4-8 Ohm, 5K: 4-8-16 Ohm (standard), other impedance per request.
  • Primary inductance: 28H
  • Primary current: 150mA maximum
  • Leakage inductance: 35mH, leakage capacitance: 114nF
  • Frequency response: 30Hz – 30KHz
  • Weight: 1.5KG per piece
  • Size: 70mm x 80mm x 70mm
  • Suitable for: 45, 2A3, 6P1, 6P14, 6V6 and etc
Quad C Core Input / Pre-Out Transformers (steel) – QCFEIP-S01
This is made using 8 pieces of C-core per transformer, having 16 pieces altogether for a pair of high end quad C core steel input or pre-out transformer (parafeed). 

This is suitable as an input / pre-out transformer between source and amplifier, pre-amplifier and power amplifier for galvanic isolation, noise reduction, increase/decrease gain, impedance matching and ground loop breaker.  If you use it as step-up, please ensure your source impedance is low enough to drive 600 Ohm load. 
  • Area of applications: SPUD (single tube amplifier), pre-amplifier, buffer, and etc.
  • Available types: 1:5.8 or 5.8:1; 600: 20K Ohm or 20K: 600 Ohm
  • Primary impedance: 600 Ohm, secondary impedance: 20K (can be reversed)
  • Inductance: 10H: 80H, DCR: 118: 760 Ohm
  • Current: NO DC ALLOWED.
  • Secondary inductance: 80H, DCR: 760 Ohm
  • Leakage inductance: 0.052H, leakage capacitance: 3.2nF
  • Frequency response: 20Hz – 35kHz
  • Weight: 1KG per piece
  • Size: 80mm x 65mm x 60mm

Amorphous Double C Core Output Transformers (nickel steel alloy) – DCAMOPT-X01
This is made using 4 pieces of C-core per transformer, having 8 pieces altogether for a pair of high end amorphous double C core nickel steel alloy output transformer for tube amplifier. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.

  • Available types: single ended and push pull
  • Primary impedance: 8K+8K (16K): 4-8-16 Ohm (standard), other impedances per request
  • Primary inductance:  50H + 50H
  • Primary current: 240mA maximum
  • Primary DCR: 198 + 198 Ohm, Secondary DCR: 0.70 Ohm (@ 8 Ohm tap)
  • Frequency response: 20Hz – 25kHz
  • Weight: 3.2KG per piece
  • Size: 100mm x 80mm x 120mm
Amorphous Double C Core Output Transformers (nickel steel alloy) – DCAMOPT-L01
This is made using 4 pieces of C-core per transformer, having 8 pieces altogether for a pair of high end amorphous double C core nickel steel alloy output transformer for tube amplifier. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.

  • Available types: single ended, push-pull(customize)
  • Primary impedance: 3.5K: 4-8-16 Ohm (SE, standard), other impedances per request
  • Primary inductance: 16H @ 100Hz,
  • Primary current: 150mA maximum
  • Primary DCR: 140 Ohm, Secondary DCR: 0.65 Ohm (@ 8 Ohm tap)
  • Leakage inductance: 9mH, leakage capacitance: 12nF
  • Frequency response: 30Hz – 30kHz
  • Weight: 1.5KG per piece
  • Size: 82mm x 65mm x 100mm
  • 3.5K / 4-8-16 Ohm

Amorphous Double C Core Inter-stage Transformers (steel) – DCAMIT-L01
This is made using 4 pieces of C-core per transformer, having 8 pieces altogether for a pair of high end amorphous double C core inter-stage transformer for tube amplifier.
  • Available types: single ended (standard), splitting (customize)
  • Impedance ratio: 1: 2.25(standard), per user request.
  • Inductance: 55H: 80H, DCR: 260 Ohm: 540 Ohm
  • Current: 100mA maximum
  • Suitable driver tubes: 2A3, 300B, 6V6, EL34 to drive 805, 845, 211 tubes.
  • Weight: ~1KG / piece
  • Size: 60mm x 80mm x 100mm
Amorphous Double C Core Choke (nickel steel alloy) – DCAMC-M01
This is made using 4 pieces of C-core per transformer, having 8 pieces altogether for a pair of high end amorphous double C core nickel steel alloy choke. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.
  • Available types: air-gapped choke (various sizes within core permit able values)
  • Primary inductance: 8H
  • Primary current: 300mA maximum
  • Primary DCR: 70 Ohm
  • Weight: 1.2KG per piece
  • Size: 60mm x 75mm x 90mm



Potted Amorphous C Core Output Transformers (nickel steel alloy) – SCAMOPT-M01 (new)
This is made using 2 pieces of C-core per transformer, 0.01mm lamination thickness, having 4 pieces altogether for a pair of high end amorphous C core nickel steel alloy output transformer for tube amplifier. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.
  • Available types: single ended (300B and etc)
  • Primary impedance: 3.5K: 8 Ohm  
  • Primary inductance: 12H
  • Primary current: 100mA maximum
  • Primary DCR: 70 Ohm, Secondary DCR: 0.7 Ohm
  • Leakage inductance: 3.7mH, leakage capacitance: 10.2nF
  • Frequency response: 30Hz – 35kHz
  • Weight: 1.5KG per piece
  • Size: 80mm x 85mm x 100mm
Potted Amorphous C Core Output Transformers (nickel steel alloy) – SCAMOPT-M02 (new)
This is made using 2 pieces of C-core per transformer, 0.01mm lamination thickness, having 4 pieces altogether for a pair of high end amorphous C core nickel steel alloy output transformer for tube amplifier. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.
  • Available types: push pull (EL34, 6P3P, KT66 and etc)
  • Primary impedance: 6.6K: 8 Ohm  
  • Primary inductance: 80H
  • Primary current: 150mA maximum
  • Primary DCR: 837 Ohm
  • Leakage inductance: 3.7mH, leakage capacitance: 10.2nF
  • Frequency response: 30Hz – 20kHz 
  • Weight: 1.5KG per piece
  • Size: 80mm x 85mm x 100mm


Potted Output Transformer
Push Pull Potted Output Transformer


Single Ended Potted Output Transformer

Notes: 
  • Please do not order if you cannot accept blemished cores. Some can look as bad as pictures but below, some has only minor oxidation. They're only superficial (on the surface) and does not affect the operations at all.
  • There may be slight physical outlook variations between what is posted here and what customers would received as batches of cores might have slight different look and sizes.  
  • There may be core imperfections and/or slight core misalignment due to the facts that they are refurbished cores. We oversize the core so that this defect will not affect the performance of the units. Please look elsewhere if you cannot accept this.

 


  

J&K Audio Design
27 FEB 2014


Product Lists  

Level 0




Level 3: depends on type, size and complexity. Email us for details.

Iso-trans: link 1, link 2
* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  

* Our product lines are always improving and increasing. If you do not see what you want, contact us!  
* Please email for volume discounts, distributor and OEM pricing.

Friday, February 21, 2014

Precision Series Transformers

Precision Series Transformers

Note: please contact customer service for latest pricing.

These are our top of the range, state of the art output transformers. All are meticulously built to perfection, with proper test and measurement being done before shipment.

Note: Standard as well as customized towards user requirements Z11 EI core transformers are available. Below are some of our past products that is available for order.

Actual frequency response curve - courtesy of our users that sent us the plot.
211, 845 output transformer, 10K, 60mA, 80mA, 100mA, 120mA frequency response curve

211, 845 output transformer 10K frequency response plot

300B output transformer 3.5K 60mA, 80mA, 100mA, 120mA frequency response curve

300B output transformer 3.5K frequency response plot

5K:8 Ohm Z11 EI Push-Pull Output Transformer (20W) - US$399/pair

  • Bandwidth: 5Hz - 100kHz
  • Tube: EL84, 45, 5842, 6C45, 6V6GT and etc


Frequency             Impedance              +/-dB      Phase
        5Hz                  3850                     -1.13
      10Hz                  4310                     -0.64
      20Hz                  4585                     -0.38      14.4 deg.
      30Hz                  4661                     -0.30      12.0 deg.
      50Hz                  4775                     -0.20
    100Hz                  4790                     -0.20      7.5 deg.
    500Hz                  4990                     -0.01
  1000Hz (ref)           5001                     -0.00      1.1 deg.
  2000Hz                   4997                     -0.00
  5000Hz                   4960                     -0.03
10000Hz                   4890                     -0.09      9.3 deg.
15000Hz                   4888                     -0.01
20000Hz                   4799                     -0.18      18.4 deg.
25000Hz                   4685                     -0.28
30000Hz                   4550                     -0.41      27.1 deg.
35000Hz                   4150                     -0.81
40000Hz                   4250                     -0.71
45000Hz                   4092                     -0.87
50000Hz                   3910                     -1.07


4.8K:8 Ohm Z11 Single Ended Transformer (10W) - US$399/pair
  • Bandwidth: 20Hz - 100kHz
  • Tube: EL84, 45, 5842, 6C45, 6V6GT and etc
Frequency             Impedance              +/-dB      Phase
      20Hz                  2659                     -2.56      43.8 deg.
      30Hz                  3159                     -1.81      37.3 deg.
      50Hz                  3711                     -1.12      28.3 deg.
    100Hz                  4141                     -0.64      19.3 deg.
    500Hz                  4670                     -0.12        7.3 deg.
  1000Hz (ref)           4808                     -0.00       5.2 deg.
  2000Hz                   4858                     -0.05
  5000Hz                   4875                     -0.06       1.2 deg.
10000Hz                   4863                     -0.06       4.5 deg.
15000Hz                   4837                     -0.03       7.2 deg.
20000Hz                   4799                     -0.00       9.9 deg.
25000Hz                   4750                     -0.05      12.4 deg.
30000Hz                   4590                     -0.20      15.0 deg.
35000Hz                   4616                     -0.17      17.4 deg.
40000Hz                   4531                     -0.25      19.9 deg.
45000Hz                   4425                     -0.35       22.3 deg.
50000Hz                   4289                     -0.49       24.5 deg.


5.0K (12:1) Ohm Z11 Single Ended Preamplifer Output Transformer - US$399/pair
  • Bandwidth: 5Hz - 130kHz
  • Tube: EL84, 45, 5842, 6C45, and etc
  • Below data are obtained using load of 33 Ohm.
Frequency             Impedance              +/-dB   
        5Hz                  1779                     -4.49
      10Hz                  2659                     -2.74
      20Hz                  3571                     -1.46    
      30Hz                  4001                     -0.97    
      50Hz                  4381                     -0.58
    100Hz                  4671                     -0.30     
    500Hz                  4962                     -0.03
  1000Hz (ref)           5035                     -0.03     
  2000Hz                   5060                     -0.05
  5000Hz                   5071                     -0.06
10000Hz                   5073                     -0.06    
15000Hz                   5070                     -0.06
20000Hz                   5061                     -0.05     
25000Hz                   5049                     -0.41
30000Hz                   5036                     -0.03     
35000Hz                   5037                     -0.03
40000Hz                   5239                     -0.20
45000Hz                   5899                     -0.72
50000Hz                   5267                     -0.23
55000Hz                   5093                     -0.08
60000Hz                   5007                     -0.01
65000Hz                   4948                     -0.04
70000Hz                   4894                     -0.09
75000Hz                   4842                     -0.14
80000Hz                   4788                     -0.19
85000Hz                   4732                     -0.24
90000Hz                   4675                     -0.29
95000Hz                   4615                     -0.35
100000Hz                 4553                     -0.41
110000Hz                 4421                     -0.54
120000Hz                 4259                     -0.70
130000Hz                 3911                     -1.07


1.0K:8 Ohm Z11 Push Pull Preamplifer Output Transformer U$ASK
  • Anode/plate current 700mA, max 100mA!
  • Bandwidth: 5Hz - 60kHz
  • Tube: 6C33C, 6080, 6AS7 and etc
  • Specially made for excellent low frequency response!
Frequency             Impedance              +/-dB   
        5Hz                   867                     
      10Hz                   904                     
      20Hz                   933                      
      30Hz                   948                    
      50Hz                   963                     
    100Hz                   977                    
    500Hz                  1002                     
  1000Hz (ref)           1000                     -5.92     
  2000Hz                   1006                     
  5000Hz                   1018                   
10000Hz                   1050                     -11.6 
15000Hz                   1103                  
20000Hz                   1163                     -19.6  
25000Hz                   1236                     -22.5
30000Hz                   1321                          
35000Hz                   1408                   
40000Hz                   1499                   
45000Hz                   1599                     
50000Hz                   1699                     
55000Hz                   1806                   
60000Hz                   1917        


3.5K:8 Ohm Z11 Single Ended Transformer - US$549/pair
  • Bandwidth: 20Hz - 100kHz
  • Tube: 300B, EL34 and etc
Frequency             Impedance              +/-dB      Phase
      20Hz                  3131                     -0.49      20.4 deg.
      30Hz                  3201                     -0.39     
      50Hz                  3331                     -0.22      10.8 deg.
    100Hz                  3391                     -0.14      7.2 deg.
    500Hz                  3473                     -0.03        2.5 deg.
  1000Hz (ref)           3478                     -0.03       1.3 deg.
  2000Hz                   3481                     -0.03
  5000Hz                   3488                     -0.02       0.8 deg.
10000Hz                   3525                     -0.03       1.3 deg.
15000Hz                   3593                     -0.11        1.5 deg.
20000Hz                   3702                     -0.24        1.3 deg.
25000Hz                   3856                     -0.42        0.5 deg.
30000Hz                   3625                     -0.15        6.8 deg.
35000Hz                   3512                     -0.01        0.9 deg.
40000Hz                   3762                     -0.31        1.7 deg.
45000Hz                   3948                     -0.52        0.9 deg.
50000Hz                   4112                     -0.70        0.5 deg.
55000Hz                   4263                     -0.86        2.3 deg.
60000Hz                   4403                     -1.00        4.5 deg.
65000Hz                   4525                     -1.11        7.0 deg.
70000Hz                   4621                     -1.21       10.1 deg.
75000Hz                   4666                     -1.25       13.6 deg.
80000Hz                   4626                     -1.21       17.6 deg.
85000Hz                   4455                     -1.05       21.5 deg.
90000Hz                   4154                     -0.74       23.8 deg.
95000Hz                   3834                     -0.33
100000Hz                 3663                     -0.20        19.8 deg.


10K:8 Ohm Z11 Single Ended Transformer - US$ASK
  • Bandwidth: 20Hz - 50kHz
  • Tube: 211, 845, GM70, 805, 250TH and etc
Frequency             Impedance              +/-dB      Phase
      20Hz                  6030                     -2.3       44.0 deg.
      50Hz                  8190                     -1.0       30.0 deg.
    100Hz                  9390                     -0.5       20.9 deg.
  1000Hz (ref)         10360                     -0.0        2.0 deg.
  5000Hz                 10383                     -0.1        7.6 deg.
10000Hz                 10229                     -0.1       16.6 deg.
15000Hz                   9932                     -0.2       25.4 deg.
20000Hz                   9680                     -0.3       36.6 deg.
25000Hz                   8635                     -0.8       42.8 deg.
30000Hz                   7948                     -1.2       50.0 deg.
35000Hz                   7176                     -1.6       56.7 deg.
40000Hz                   6366                     -2.2       40.0 deg.
45000Hz                   5541                     -2.6       66.6 deg.
50000Hz                   4112                     -3.1        0.5 deg.

J&K Audio Design
22/02/2014

Product Lists  

Level 0

Level 3: depends on type, size and complexity. Email us for details.
Iso-trans: link 1, link 2
* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  
* Our product lines are always improving and increasing. If you do not see what you want, contact us!  
* Please email for volume discounts, distributor and OEM pricing.

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Product Lists

Product Lists

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Level 1: link 1, link 2, link 3, link 4

Level 2: link 1, link 2, link 3, link 4, link 5, link 6, link 7, Link 8, link 9

Level 3: depends on type, size and complexity. Email us for details.

Iso-trans: link 1, link 2

Power-trans: link 1

* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.

* Our product lines are always improving and increasing. If you do not see what you want, contact us!

* Please email for volume discounts, distributor and OEM pricing.

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