Referencing the classic Marantz Model 7 preamp, we have come to our first self-assembled unit, the M7U1 preamp.
The external chassis is a solid and full-aluminum case to house the internal parts. While this is a tube preamp, the rectifier and driver tubes are small and are served better to be encased within. The tubes remained well-ventilated with top opening of the case but still allowed stacking of other similarly-sized equipment on top. The beautiful brushed metal of the silver panel on the front definitely sports a sleek and contemporary look, kept clean with just a volume knob in the centre.
At the heart of the preamp is where we did most of the work to make it shine even better than some of the similar stocks one may find online. There is no other means one could find such preamp referencing the Model 7 design that uses ClarityCaps as the coupling capacitors other than our M7U1. This upgrade seems extravagant to some, but it was completely worthwhile. For the rest of the other capacitors, we have continued our top-range of fine selection – Nichicon KX and Vishay BC caps.
Another area we improved further on this preamp was the modification of the rectifier tube acceptance – from 6Z4 to 6X4. 6Z4 tube types have always been a mainstay in a lot of Chinese preamps due to the low cost and wide availability. However, the capability of this tube is never going to surpass its much-better cousin, the 6X4s. While it could be quite common to find a very basic 6Z4, there is limitation to want to upgrade to a better 6Z4 as the choices really are restricted. 6X4 on the hand, has way more options to choose in terms of improving the already-better sound further, from the various European and US vintage tubes available. Their affordability plus capability is a great incentive for us to allow 6X4 to be able to use in our preamp straight without the need of a converter. So we did the conversion right on the tube socket! To be included in the set is a vintage GE 6X4WA!
The high quality of the other components include the use of twisted Silver-plated Copper (SPC) cables as the internal wirings and even as ground. Internal wirings without shielding often suffers from interference, but as the cables in this case are short and twisted, they are less susceptible to be affected by interference and noise.
Controlling of the volume is done smoothly with the ALPS pot made in Japan. At the back of the preamp is the stylish matte-looking and gold-plated RCA ports made in Taiwan.
12AX7 has been commonly the tube type used in preamps due to their high gain and sweetness of the tone they produced. After seating three of these Shuguang 12AXs in, this preamp is a superb renderer of hyper-realistic vocals. The sweet and smooth midrange has brought out the nuances of singers and instruments, ideally to be used in Jazz and Vocal genres of music.
Made to order in 18 days.