Jump to content
Sign in to follow this  
QubesAUDIO

Yulong A28 Class A Headamp SALE

Recommended Posts

A28 fully balanced class A headphone amplifier S$799 Only Silver color left Last 3 sets Now CNY offer $688

a28s2_zpsd187e266.jpg

a28b1_zps73804146.jpg

a28bb3_zpse3abd04b.jpg

A28 is a fully balanced class A headphone amplifier constructed by 4 amplification channels. Its complete connections are convenient to connect source and headphones with different terminals.

Outputs:

Unbalanced 6.35mm, 2 sets

Balanced 3 pin XLR

Balanced 4 pin XLR

Inputs:

Unbalanced RCA

Balanced XLR

The circuit, construction and components are fine tuned and selected over years of design and listen experience, aimed for best sound quality within a certain cost, and not just use hifi grade parts in blind. The amplification is OPAMP driven complementary transistor buffer (also known as “Diamond Buffer”). After trying dozens of OPAMPS – from pristine NE5534 to the latest offers from major manufacturers, OPA 2604 was chosen because we feel it sounds most balanced in this particular design. The output is MJE243/253 middle powered transistor.

Other details include: Plitron power transformer from Canada, Neutrik XLR connectors, and Alpha 4-gang potentiometer made in Tai Wan. Unbalanced inputs are converted to balanced signal by an OPA1632, and the balanced/unbalanced input selection is done by a group of relays to optimize signal path.

Use note: use balance input can get better performance , Input signals from the rear panel switch selection. Two headphone jacks of the front panel is double jack, can connect double 3 pin balance headphones, also can connect 6.35 headphones. 4 pin balanced output can only be connected 4 pin headphones, not through the connector to connect unbalanced headphones, otherwise it will damage it

 

Please be noted, if you use a same source to feed A28, do not connect the RCA and XLR interconnects altogether. This will cause common ground interference and degrades the performance of the RCA input signals. (This applies not only to A28 but other similar products in our tests).

 

Practical Performance:

●SNR:>120dB

●THD+N: 0.0005%

●Crosstalk >100dB

●Frequency response:20-20KHz-0.3dB

●Balance output power :600ohm:400mW 300 ohm:700mW 150 ohm:1.3W 32 ohm:2.5W

●unbalance output power: 600ohm:120mW 300 ohm:200mW 150 ohm:350mW 32 ohm:800mW

●Power Consumption: <30W.

●Dimensions: 250*200*55mm.

● Weight: 3Kg.

P18 Power Processing Center S$339 Now $288 with IeGO Gold plated IEC

P18b_zpsf5787465.jpg

P18_zps4e803158.jpg

Common power filters are usually designed for home appliances and come with tiny ferrite core. Using this kind of design on audio systems will compress the dynamic and loss the details. YULONG’s engineers have many years of experiences in power source design for telecommunication base station and audio equipment design. By utilizing their skills and experiences, they designed P18 power filter.

P18 uses an enormous ferrite core, winded with 11 AWG Pirelli wire.

Vishay 8uf X2 MKP as common-mode filter

Vishay Sprague Y2 as differential-mode filter

Vishay transient voltage suppressor is used for avoid sudden impulsive noise signal

LITTLEFUSE varistor (VDR) is used for absorbing voltage surge

Double layer parallel wide traces on PCB with 20 ounce copper.

11 AWG Pirelli wire is used for internal wiring.

Schurter IEC inlet socket

Cooper IG8300 receptacles

Specially designed aluminum enclosure provides great Electromagnetic shielding

Two groups of output, separates digital and analog equipments

Phase and grounding error LED indicators

 

P18 provides great contact performance and capable of handling 6000W power dispatching. With high standard filtering, P18 provides continuous pure powers to audio equipment. As a result, P18 gives a fantastic listening experience with detailed, full and rich sound in a dark background.

Buy with peace of mind with local 1 year warranty.

Drop by to hear it for yourself.

Qubes_zps9a8097eb.jpg

KC.Tan

Qubes AUDIO

756 Upper serangoon road, Upper serangoon shopping centre #04-35 (S)534626

Tel: 90693001 whatsapp/sms for demo appt

Open Sat 1.30~6pm

Share this post


Link to post
Share on other sites
Sign in to follow this  

×