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Friday, January 17, 2014

5K Push Pull Output Transformer



5K push-pull output transformer

We’ve received an order from Mr.’tubeworld’ (alias in diyaudio.com) from Singapore and he’s about to pick up his Precision Series 5K push-pull output transformer when he drops by for holidays. He used our Vintage Series output transformer and was very delighted, now he wanted more.

According to our email and phone conversation, looks like Mr.’tubeworld’ has quite extensive experience on DIY tube amplifier and he’s looking for an alternative to the famous L-brand transformers. Since Singapore is just across the straits, he’s wondering if there are quality vendors in his neighboring country. He was recommended by another local DIYer to look for us for customized transformers. 

Apart from power transformers, PSU chokes and plate chokes, a pair of HIGH QUALITY 5K push-pull output transformers was ordered. 

His current L-brand output transformer is excellent in quality, but he feels that the mids are not as warm and thick as he wished. He has heard about our Vintage Series but he wanted more and wanted only the best. We have to properly design and implement this, especially considering that he has a lot of famous output transformers at his disposal to compare with ours, LOL! There goes nothing! 

Without further ado, the 5K push-pull output transformers were completed (on expedite mode) and our guru did some measurement, and we were really quite delighted with the all hard work put-in to make this possible. Here goes the results, tested with HP4192A:

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

We keep up with our standard/promise: 5Hz – 50kHz +/- 1.2dB (we better it infact!) 

Based on such test data, it should be a very well balanced, linear output transformer. The other components on the amplifier will be the limiting factor instead of the output transformer. Mr.”tubeworld” should be very satisfied with this pair of 5K push-pull output transformer.

Thanks for watching! Hope to hear the feedback from Mr.”tubeworld” after he uses and compare this with the other famous manufacturers! 

J&K Audio Design
18/Jan/2014

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* 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.

Saturday, January 11, 2014

J&K DAC Prototype

11 January 2014 - a new beginning.1  - Products,

J&K had a field trip to test out the J&K DAC (digital to analog converter) prototype.  The system owner came to J&K laboratory a week ago and liked the sound of our test system and asked if he could audition the upcoming J&K DAC before he pulls the trigger to own an official unit. Official J&K DAC will have USB input as well and that's the direction he's heading as well - CAS.

Well, since his house is just 30 minutes drive from our place, and having a chance to try out the DAC at another system is for sure welcomed! Although our DAC is just a prototype with very basic and down to earth implementation, we still feel that it is already showing its potential when it replaced our existing DACs (non-oversampling DAC + high resolution 32b/384kHz DAC). In our system, it swamped both of the DACs in terms of resolution, vocals as well as both high + low extremes.

Without further ado, let's take a look at owner's system:

Unison Research, Esoteric, PurePower AC filter and J&K DAC prototype
Transparent Audio Speaker Cable

Left bottom - J&K prototype DAC in a temporary chassis
J&K prototype sits quietly beneath the Unison Research Performance amplifier, like a crouching tiger, waiting pounce on unsuspecting preys.
Audio Physics Virgo floorstander (25th anniversary edition)
Esoteric CD / SACD Player

Unison Research Performance Integrated Amplifier + J&K prototype DAC in focus!

PurePower AC Conditioner

Unison Research Performance (PSE using 3 KT88 per channel)

Music used in the audition:

蔡琴:机遇

Diabolus in Musica, Accardo interpreta Paganini

玉置浩二:酒紅色的心

Extensive A - B comparison are done on the original CD player versus the J&K DAC over CAS. There were unfairness in the comparison as well as the player is many times (~10x) the price of J&K DAC, not to mention the cabling used as well where J&K DAC is only connected by only low end series of Monster Cable interconnects and coaxial digital cable, and generic el-cheapo IEC power cords connected to the wall for the DAC instead of through PurePower. 

Results?

J&K DAC is better in terms of airiness, 3D imaging, clarity, and scale but weaker at the bass region. J&K DAC is more relaxed (宽松庞大,空间感良好) and offers the sound that the owner prefers. We believe that when our DAC is properly implemented (a real production unit), it will improve on all the aspects and be a better performing unit.

Nevertheless, system owner, without hesitation, ordered a unit of our DAC after the brief listening session that lasted for around an hour.

We have to start busying to get the J&K DAC ready in ~1 month time  - period.


J&K Audio Design
11/1/2014

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, January 9, 2014

Western Electric Cables

*** We no longer carry Western Electric Cables. Please visit Audiobits HIFI for WE Cables. ***

Western Electric

Mind you, cable works, and it works especially well if your system is up to a certain level. I used to disqualify cables but now it is one of the useful tools to tweak the system to where you want. 

Here, we would like to introduce you to the world of Western Electric by starting with the cables. For advance users, they can go for Western Electric amplifiers, WE transformers, WE chokes, WE output transformers, WE capacitors and etc. There are endless ways to play with Western Electric components!
First ever Western Electric Interconnect (obsolete)
Western Electric Interconnect MKI
Western Electric Interconnect MKI
Western Electric Interconnect MKI

Western Electric Interconnect MKI
Western Electric Speaker Cable
Western Electric Speaker Cable
Western Electric Speaker Cable
Western Electric Interconnect MKII
Western Electric Power Cord MKII
Western Electric Power Cord MKII
Western Electric Power Cord MKII
The Western Electric interconnect is made of Western Electric 50’s 0.62mm diameter copper cable. Every interconnect cable uses four 0.62m copper cable twisted together, 2 for positive, 2 for negative. Then, a layer of copper braid enclosed the cable before the mesh protector is applied. Shielding property of this interconnect is very good. Imposing a power cable on the interconnect shows no audible noise at all.



The character of this cable should be categorized as – thick, warm, extended bass, fluid; good for thin & dry sounding systems. It is definitely worth trying with such a price to get the legendary Western Electric sound into your HIFI setup. 



WE interconnect MKI 1.8M        USD$99/pair
WE interconnect MKII 1.0M       USD$79/pair
WE interconnect MKII 1.5M       USD$99/pair
WE speaker cable 3M pair         USD$199/pair
WE digital coaxial (RCA) cable USD$129/pc
WE power cord (2M) US style   USD$129/pc  


User comments:

#1
Just received the power cable along with the RCA and digital interconnects. Plugged everything into my CD transport and DAC and popped in the CD to make sure everything was working.

Initial impressions are that some burning in is required but bass seems a bit more solid and the soundstage also seems more defined with better separation.

Not sure which cable was responsible for all of part of the above and will experiment further.
 

#2 
First of all: quiets are much more quiet, great detail, very, very musical and a lot more detail. It has replaced a R*** A****** K***** Classic. Very pleased with the build quality and components used.

#3
Hm... not bad. Very dynamic and transient. Eager for after run-in... Went for a marathon run-in...Holy cow! What a cable...! Worth every cent of it...and much more. Now I'm unable to unhook the cable...Love it, man! Check it out for yourself and discover...

#4
i've been using a pair of your western electric interconnects hooked up to a pair of stax headphones thro a cd player, and dac.... sounds marvellous. Clear and clean sound, wonderful sound stage. Replacing them with K****** KC*G, which is a thousand usd, i had a hard time finding any significant change except that your cable sounds more dynamic. And it's still breaking in !

#5
The interconnects that i have experience using in the various systems at my place (both with my magnaplanar MMG set up as well as seperate headphone based system with stax headphones) are K***** KC*G, X***** cabon, D* labs silver sonic, and Analys*s plus oval one.

The mkII that i am using is astonishing for the price. I wanted to splash out about 1K for interconnects for my stax set up but am glad that at the last moment i decided to try the cables, and am so glad i did. They are extremely musical, a joy to listen to. Won't be spending silly money on interconnects anymore. Very Happy

Want to try the digital cable next, hopefully can get after Raya! Right now i'm using a different brand for the digital cable, and am hoping the synergy of using same make cables in the whole system would pay off. will keep you posted.
 

Cont'

I let the interconnects burn in for the past few weeks, and the sound is so much better.

This evening i took out my K***** KC*G and compared the sound... shocked. The timing of the two cables is so apparently different. And the one that does a better job of timing and pace and rhythm is the WE cable. I can't go back to the k******... today i found out that emotion in music is absolutely dependant on timing. one cable is competent but leaves me cold(KC*G). The other cable is causing me to have goosebumps and to get up and dance, well, dance as much i can with a Stax headphones on my head. The difference is due to timing. You can actually hear that both cables have different timing, it's so clear! the rhythm is presented so clearly with the WE  cable. I don't have to struggle to follow the flow of the musical story as it unfolds, as it just comes shining thro. Listening to 'Throwing Copper' by Live. Man what a ride! I cannot believe that one cable is close to a thousand greenbacks (give or take, for a meter pair) and the other is *****. Just goes to show you don't have to spend crazy money to get crazy good sound.
I am very sensitive to upper frequency exaggerations and sibilance, and as far as i can tell there is no difference between the two in this regard. Bass in the WE  is full and excellent. As is the soundstage as presented by my headphones.
I am astonished to have this amount of excellent sound qualities in a cable of this price and consider this to be one of my best hifi purchases in terms of value for money.
The digital cable is still cooking/burning in.
Just sharing my 'mini-review'. Hope it helps someone make better interconnect purchases.

Too many to list... :)

J&K Audio Design
9/1/2014

Saturday, January 4, 2014

New amp on the block - part 2

As promised, more pictures... it's getting cramped inside... due to owner wanting a small chassis, wiring work is hard in such small space with so many trannies needed for the design.

Lundahl LL9202 installed.

Plate chokes mounted. Power trans awaiting encapsulation.

J&K Audio Design
5/1/2014


Product Lists  

Level 0

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

Wednesday, January 1, 2014

New amp on the block - creating something special!

Coming soon! Working on a customer amp...

6 tube design - integrated tube amplifier in the making... guess what design and what tubes are used?

9 transformers in total - 2 power, 3 PSU choke, 2 anode choke, 2 OPTS... I think it will weight 40kg or more... 


holes marked to be drilled
most of the holes drilled, including 6 holes for tubes

start mounting tube sockets

add in DC regulator + filament power transformer

wiring turrets added, more transformers mounted

front view with tube sockets mounted

getting the wires through the openings

mounting turrets
J&K Audio Design
01/01/2014

Product Lists  

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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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* 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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