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Showing posts with label DAC. Show all posts
Showing posts with label DAC. Show all posts

Thursday, December 10, 2015

Tube DAC

We've built an interesting DAC for a local customer - a dual topology tube DAC! It has switchable DACs with a NOS (Non Over Sampling) DAC and a high resolution modern oversampling DAC. 

Features
Switchable dual DAC 
Driver Tube: NOS Mullard EL821 Triode Connected
Rectifier Tube: GEC 5Z4G 
DAC1: NOS TDA1545A quad paralled
DAC2: ESS ES9023
Transformers
* Level 3 Nanocrystalling Double C Preamp OPT 10K: 300 Ohm
* Level 2 EI Z11 power transformers and chokes
Solid full ALU chassis with CNC cut ventilation holes and tube holes
5MM FR4 PCBA for tube mounting
Special vibration and EMI/RFI tuning from 3io's 
Ultra low noise regulators array for DAC

Sound - dynamic, extended on both ends, excellent PRAT, warm and thick vocals.


Time for some pictures of this very unique and high end tube DAC. Apologies for the low lighting. Our semi-pro camera man still needs time to get used to his new full frame Canon SLR.





Some internal pictures. This guy is whopping 20KG!






Full system view - Acapella Violon4, Wavac PRT1 preamp, J&K EL84 PP amplifier, REL reference subwoofers (x3), Wavac 805 mono-block power amps, Wavac 300B power amp + full set of Wavac regulators, and etc.


J&K Audio Design
12/11/2015

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.

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.


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Product Lists

Product Lists

Level 0: link 1

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.