NOTE： we don't ship the item to PO BOX address， and we only ship the item to English address, so please leave us your physical English address when you pay.

If your country is not listed in our shipping policy, pls tell us your city and zip code, we will check whether your city belong to remote area or not, then tell you the accurate freight.Tks for your understanding and coopearation.

please select the voltage you need from 110v and 220v, or we'll select one for you according to the voltage your country has.

  we have black&silver color，if you do not have special need, we will send it at random.

Technical Parameter
Input impedance:100 Kohm
Output impedance:600 ohm
Total Hamonic Distortion:less than 0.01%
Frequency Responses:20Hz-30KHz+-1dB
Signal to Noise Ratio :90dB
Input Jack:4 groups
Output Jack:2 groups
Supply Votage:AC110/220V 60Hz/50Hz.
Size:435mm(width)*90mm(height)*290mm(Depth)
Used tubes :12AT7*2PCS,12AU7*2PCS,6Z4*2PCS
Working enviroment:Temperature:5-40 dgrees
                   Humidity:35%-80%
Net weight:about 5.6kg

Thank you for listening to our 728A tube preamplifier.The function and appearance of this unit now are perfect after going through improvements for several times.
The pre-amplifier improved based on famous Wada ,Shigeho's Style Electric ,which was introduced by Wada Shigeho in the early 1960s and gave an excellent performance.
Using the entire circuit board design,internal layout is more rational and refined.
Brushed aluminum(8mm thickness)siliver faceplate,with all metal buttons and knobs,plus blue LED indicator light and unique tubes display window.
(2)groups of RCA outputs:one with low impendance output and one with high impedance out put.The unit not only can be connected to power as a preamplifier ,but aslo can be connected to integrated amplifier as a timbre regulator and improve the sound quality of whole system.
R-shape high efficiency transformer and gold coated RCA connectors plus outputs terminals.
Adopts 4pcs of paper in oil capacitors and German WIMA capacitors for coupling effect,make the sound warm and more details.

All resistors and capacitorsare audiophile grade to ensure sound quality.
The unit have Bass and Treble Controls and volume,balance adjustment on it plus tone bypass function,it bypasses the treble and bass controls ,so you get a more "neutral"and original sound.