Audio buffs have often referred to the time period of 1940 to1960 as the “Golden Age of Tube Audio”. During this time period every home audio amplifier in production contained vacuum tubes. In 1947, John Bardeen and Walter Brattain developed the point transistor, which eventually had a profound effect on the audio world. While the transistor was an engineering novelty at this stage, in 1950 William Shockley developed the “bi-polar junction” transistor. This new design is the blueprint for the current generation of transistors, and contains the same basic architecture as a modern component. The age of solid state was ushered in, and vacuum tubes were now considered obsolete. Over the years there were audio companies that kept this archaic technology alive, and continued to produce vacuum tube amplifiers and pre-amplifiers. The audio community recognized the unique sonic qualities of these components, and continued to buy them despite their hefty price tags. Over the years, the tube audio niche has prospered, and even increased in size. Proponents of vacuum tube electronics would argue that we have entered the “Second Golden Age” of tube audio. The number of manufacturers that offer tube based equipment is far greater than any other time frame since the 1950’s.
- Shuguang Tubed Amplifier SG-S8 from Ming Yi Audio
- Output power 50 w x 2
- Response 10Hz – 80Khz
- SNR > 85 dB
- In sensitivity < 500 mV
- Out impedence 4 & 8 Ohm
- Tubes KT88 x 4, 6SN7GTx 2, 6SL7GT x 2
- Dimensions 410 x 335 x 210mm
- Net Weight 26.5 Kg
- Price: $899
- Ming Yi Audio, Fu Rong Yuan, Changsha, Hunan, Peoples Republic of China 410001
Shugaung S-8 review
The Shuguang Electron Group Co is one of the few companies that continue to produce vacuum tubes. It was founded in 1958, and s located in the Hunan province of China. Over the years, Chinese tube manufacturers have worked diligently to improve their products. Several categories of current production tubes now have the reputation of high quality sound, and a reasonable selling price. The Shuguang KT-88, and the 300B Meshplate output tubes have a devoted following in the vacuum tube sub-culture. Shuguang has decided to expand their offerings, and has developed a new line of tube electronics. The S-8 is a 50 WPC integrated amplifier that sells for a modest $995. This amplifier offers the audio enthusiast with limited means the ability to experience the benefits of tube amplification.
The output stage of the S-8 utilizes four Shuguang KT-88 tubes. This is a robust tube, and well suited for use in a 50 watt per channel amplifier. What is interesting is the use of octal tubes in the predriver and splitter position. Companies that produce inexpensive tube gear usually choose 9-pin miniature tubes for these applications. Shuguang has chosen to use the more expensive 6SL7 and 6SN7 tubes. The vacuum tube community generally agrees that the octal category of tubes is a superior sounding tube to the majority of 9-pin tubes that are currently offered. Shuguang should be given high marks for their decision to use their best tubes in the S-8.
Biasing the output tubes of the S-8 is a straightforward task. A test point and trim pot for each KT-88 is located on the side panel of the amplifier. A multi-meter is needed to determine what level of bias current is being supplied to the tubes. Use a small screwdriver to rotate the trim pot, and observe the corresponding change on the meter I set the bias to 45 milivolts, and noticed that a small amount of background hum from the amplifier completely disappeared. When compared to the S-8, my Electra-Print 300DRD mono-blocks are a hassle to set the bias on. Even a novice tube owner should be able to successfully bias this amplifier.
Chinese manufacturers have been producing parts and components for other audio manufacturers for several years now. These manufacturers have gained the technical knowledge and experience necessary to develop their own offerings. The S-8 primarily uses parts produced by Chinese suppliers. The inside of this amp is populated with large electrolytic power supply capacitors, metal film resistors, and several polypropylene capacitors. Shuguang engineers decided to use an ALPS Electric switching device in this amplifier. A high-quality switching device at the input stage is essential to the performance of an amplifier. This is another positive aspect to the design of the S-8, and should not be overlooked by a potential owner of this amp. The layout and assembly of this integrated is stellar. This amplifier was not slapped together in order to meet a low cost. The neat assembly of the S-8 is a reflection to the skilled workforce that Shuguang employs. The S-8 is a nicely assembled integrated amplifier, and it is an excellent example of what can be found in the sub $1000 price category.
The fit and finish of the S-8 amplifier is significantly better than what is normally seen on inexpensive electronics. All of the panels and screw holes line up correctly, and there are no flaws that can be found in the assembly of this amplifier. The chassis has an attractive paint job that adds to the overall impression of this being a carefully constructed component. There is an acrylic plate that is fitted around the tube sockets, and is backlight by a pair of blue LED lights. The backlighting is a nice touch that gives the S-8 an unusual appearance. The designers opted to use a set of transformer covers(1.) in order to maintain a neat appearance. These covers are the same height as the tube cages, and therefore maintain a uniform appearance. Four small input selector buttons are located on the front panel of the amplifier. All interconnect and speaker wire connections are made on the back panel. The speaker wire binding posts are substantial, and can easily secure stiff, or large cables. While the Shuguang amplifier may be modestly priced, the visual appearance of this amplifier reflects the attention to detail that has been invested in the manufacturing process.
An integrated amplifier is essentially a pre-amp and power amp built on the same chassis. With the S-8 in my system, all I was required to do is provide a pair of speakers, and a digital source. I have the Eminent Technology LFT-16 speakers on hand for a little while longer, and I decided to use them in this review. My Audio Nirvana Super 12 speakers are far more efficient than the LFT-16, and do not place a challenging impedance load on the amplifier. The Audio Magic Kukama DAC, and JVC XL-Z1050TN CD player were the digital combination I used. A Monarchy AC Regenerator provided clean power to both the digital pieces. Audio Magic Illusions 4D speaker cables and interconnects made the necessary connections between components. All components that had removable power cords were fitted with Audio Magic Extreme series cords.
Over the years audiophiles have appreciated the ability of tube amplifiers to create a realistic presentation of vocals and instruments. The Shuguang integrated amplifier does a commendable job in these regions, especially when you factor in its affordable price tag. Diana Krall has a lively rendition of “Frim Fram Sauce” [Stepping Out The Early Recordings; GRP Records GRD9825], which showcases the abilities of this amplifier. Kralls vocals have a precise presentation that reveals all the subtle variations of her singing style. Thankfully, the S-8 does not add any romantic warmth to the song, which is a common trait of many value priced tube amplifiers. The tonal balance of this amplifier is not ruler flat, it has an elevated region in the upper midrange spectrum(2.). This elevated presence region tends to highlight female vocals, and can be enjoyable to listen to. This peak can be heard when carefully listening to the tone of the piano. A piano is a notoriously difficult instrument to reproduce, and I would say that this amplifier handles this task in a competent manner. I spent several evenings listening to a wide range of female vocalists through the S-8, and my appreciation of the abilities of this amplifier increased at the end of each listening session.
The Shuguang amplifier overall sound can be categorized as quick and lively. I moved my focus to the percussion performance of the Diana Krall song. I could clearly hear the differences between each stick strike on the drum kit. Also the decay of each strike has clearly recognizable differences. The cymbals have a metallic texture to their sound, which can be difficult to reproduce. There are several challenging passages in this recording, yet this disc does not trip up the Shuguang amplifier. In the critical midrange region, the S-8 performs at a level that belies its modest selling price.
The ability to create a multi-layered soundstage is one attribute about tube amplifiers that I have a deep appreciation for. Coincidentally, this is also the main strength of the Eminent Technology LFT-16 speaker system. The combination of tube amplification and planar-magnetic speakers produces an aural illusion that can draw the listener into a performance. In 1985 Kate Bush produced an album with a strong Pink Floyd influence that I believe is the pinnacle of her career. The surreal presentation found on the song “Waking the Witch” [Hounds of Love; EMI-Manhattan D 107779] has a surreal feel to it, and can produce a soundstage that is wide and deep. This song presents various voices moving throughout the soundstage, a snippet of ringing church bells, and short radio transmissions emanating from a point deep in the soundstage. While this song may be the creation of a talented studio engineer, it offers an unusual aural experience that I find to be captivating. The Shuguang amplifier and Eminent Technology speaker system is capable of reproducing a soundstage that is equal in depth and width to the one formed by my reference system. This equipment pairing also keeps proper spacing between vocals, instruments, and various sound bites. The LFT-16 speaker system requires a high quality amplifier to fulfill its potential. Clearly the Shuguang S-8 is up to this task.
Deep and powerful bass response is not the forte of lower powered tube amplifiers. High-powered tube amps can do a respectable job at creating subterranean bass notes, although they generally lose out to their solid-state counterparts. My experience with this amplifier validates this generalization. The Shuguang amplifier does a fine job in the mid bass, and the upper bass region. The Eminent Technology speaker utilizes a 6.5-inch bass driver, and is not capable of deep bass response. In order to properly evaluate this parameter, I swapped in the Audio Nirvana Super 12 speaker system. The 12-inch driver extends deeper into the bass regions, and the higher sensitivity helps out a lower powered tube amp. Portland Taiko is a North American drum group that I was fortunate enough to attend their performance at a local community college performing arts theatre. “Doodaiko” [Making Waves; Northwestern Inc. Released Spring 2000] is a piece that features an Odaiko, which is a drum of massive proportions. If I remember correctly, Portland Taikos drum spans nearly 5 feet across, and is has the impact and power unrivaled by any other percussive instrument(3.). The Audio Nirvana speaker is not capable of accurately reproducing this instrument, but it makes a valiant attempt at doing so. The Shuguang S-8 amplifier gets the upper portions of the bass drum right. As the bass notes extend deeper, this amplifier just does not have the power reserves necessary to meet the demands of the music. Fortunately, the bass just rolls off and diminishes instead of becoming bloated or uncontrolled. When pushed beyond its limits, this amplifier performs gracefully, and does not draw attention to its limitations. Other musical instruments will not put the demands on the S-8 that the Odaiko does. For instance, this amplifier can believably reproduce an acoustic bass, or bass guitar. If the S-8 is partnered with an appropriate speaker, it is capable of meeting the needs of your average music listener.
Earlier this year I reviewed the Antique Sound Lab MG-SI 15DT integrated amplifier. The ASL amplifier has a pair of RCA jacks that allow the owner a convenient way to match it with a subwoofer. While the Shuguang amplifier has more than twice the power on tap than the ASL does, it still would benefit from this feature. A good subwoofer is capable of filling out the lower registers where the S-8 has limited output. Many subwoofers have a high level input option, and can be hooked up to the speaker outputs of an amplifier or receiver. It’s not a very elegant solution, and does not provide the subwoofer with a low distortion input signal. The Audio Pro Avantek subwoofer has this option; so one evening I partnered it with the Shuguang amplifier. The installation was straightforward, and the results were acceptable. When I replayed the Portland Taiko disc, the drum notes extended deeper, and had increased impact. A subwoofer output option would a degree of flexibility and convenience that would be appreciated by a perspective owner. I would suggest that Shuguang should evaluate the possibility of adding one.
The Shuguang Corporation deserves high marks for building a product that is affordable and musical. Many audio enthusiasts who are interested in exploring the world of vacuum tube amplification are put off by the high price of most components. The S-8 has the sonic attributes of a good tube amplifier, especially in the crucial midrange region. This integrated amp does a fine job of reproducing vocals. If this amplifier is used with a good speaker system, it is capable of generating a huge, solid soundstage. I can easily recommend the Eminent Technology LFT-16 speaker system as a viable candidate. The build quality of the S-8 is on par with other components I have owned from several highly regarded high-end companies. If I were to judge the price of the S-8 based on its fit and finish, I would not guess it sells for less than $1000. For those audio enthusiasts who have limited funds in their audio kitty, the Shuguang S-8 integrated amplifier would be a wise choice to build a moderately priced system around.
- The transformer covers are larger than the actual transformers. I was unable to verify the quality of transformer that is located inside of the covers. I would like to have seen Shuguang pot the transformers since there are covers being used.
- I have listened to Shuguang 6SN7 tubes in the past. In a pair of AES SE-811 amps, I experienced the same type of upper midrange emphasis as I did in the S-8 amplifier. I believe this characteristic can be addressed with a different pre-driver tube. I no longer have the appropriate tubes to substitute, so I cannot verify my opinion.
- The performance took place in a large theater; our seats were located half way back, approximately 30 feet from the stage. During the playing of the Odaiko I was able to observe the individual drum strikes in my spouses soda pop. It created a ripple in the drink, reminiscent of the scene in the first Jurassic Park movie.
from aﬀordableaudio, By John Hoffman