August 2011

World Premiere!
Shengya CV-1 Tube Preamplifier
High quality construction and components.
Review By Ron Nagle

  In most every high quality, audio system the preamplifier is the most important link in the musical chain; it is the conduit through which every source flows. And if it speaks with a definable accent then everything downstream will adopt the same tonal inflections. Neutrality is the most important consideration when designing what is in essence an audio switchboard. If in fact you do succeed then you will have a length of wire with no voice of its own. Therein lies the reviewers rub.

Sheng in Chinese means Sound and Ya means Elegant. The English translation is, Elegant Sound CV-1 Tube Preamplifier. Alas, perfection has yet to be found, perchance, a voice pleasing to the ear? This is what I aspire to inquire.

The Source
The time has passed when Made in China was a warning. Today there are many quality products bearing American, English, Canadian, Et Al, company names.  However only a handful of these tell us they are actually manufactured in China. A notable exception would be my Prima Luna Prologue 2 Integrated Amplifier. It bears an Italian name, is designed by Marcel Croese in the Netherlands, and is manufactured in the People’s Republic of China.

Let me tell you about Ian and Rachel of Grant Fidelity. Speaking with them at audio events over a period of years, I believe I understand their marketing skills. Grant functions with an intimate knowledge of quality audio products and the Chinese manufacturers who make them. They select only a few high-end components to import and direct distribute in North America. In addition, this Canadian Company has its own line of Original Equipment Manufacture (OEM) products. I will have to admit what initially captured my attention was Grant Fidelity’s pricing policy. On their web page, they list the manufacturers suggested retail price along with their marked down price. Our review subject is the Shengya CV-1 preamplifier. The CV-1 is $3000 yet Grant Fidelity sells it direct on their web site for $2200 including shipping.

Chinese Esthetics
If Computer Numerically Controlled metal milling machines were likened to an artists brush, than the CV-1 might be a portrait in metal. The faceplate is a 5/8" thick aluminum slab. The entire over built chassis body is fabricated of satin black anodized aluminum panels. The preamplifier weighs just over 25 pounds and the construction and appearance is very substantial, more like an integrated amplifier?

The Works
The CV-1 is a dual mono nine-tube preamplifier with separate output transformers. It rests tripod like on three rubber feet. The two that support the front of the preamplifier are located beneath two round metal columns. It has balanced and unbalanced output and input connections. At the back, there are five pairs of RCA input jacks and one pair of balanced XLR input sockets. Additionally the output connections consist of two pairs of RCA female connectors and a single pair of XLR sockets. I found all of these jacks were gold plated and of a very high quality. Note: Both types of output connections are active when the amplifier is on. However, it is not advisable to mix balanced and unbalanced outputs for a bi-amplified system because the two use different grounding schemes.

Nine vacuum tubes, a mix of two 12AX7 and seven 12AU7 dual triodes, power the CV-1. There is no schematic or circuit description provided with the preamplifier and the owner’s manual is very basic. With some difficulty, I removed the eighteen Allan head machine screws holding the top cover in place. Inside only two vacuum tubes were stamped with the tube type and the word, China, all were no brand clear glass. However tube rolling /substitution is still possible because the main circuit board is labeled with the tube locations. My exploration of the CV-1 interior revealed high quality wiring and construction plus high quality parts. A neatly laid out two sided main circuit board housed many German made WIMA metal film capacitors, two M’Cap capacitors and nine very nice gold pin ceramic tube sockets. The top of the preamplifier has ten round openings that provide ventilation for these tubes. A separate raised center front panel supports two large control knobs. The left side knob will switch to one of the six input sources and on the right side there is a motor driven Alps volume control. At the bottom of the faceplate are six silver colored source select push buttons. The input sources are designated numerically and numbered from one to six, with the S-6 position switching to the single XLR input. Centered just above these six buttons is the on/off power button.

The handheld remote control designated SRC-22 is an oversized oval shape and is milled from thick aluminum stock. The remote control mimics the functions of the six front panel source select push buttons. In addition it controls volume and adds a mute function along with a gain button for system matching. This function can switch between two voltage output levels.  At the Grant Fidelity site, I found this listed feature: "A 30 volt pure Class A tube output to match almost any power amps". Manufactures features and specifications will be listed at the end of this story.

The CV-1 sounds surprisingly clean and clear to the point that I struggled to find a hook to hang a description on. I decided to listen to the preamplifier with my little Aurum Cantus Leisure 2 SE speakers and once again, they helped to fill in many of the answers. The ACL 2 SE speaker’s great strength is a revealing ribbon tweeter that can reach 40 kHz. For a nine-tube preamplifier this is the most untube sounding tube powered component I have experienced. My Audio Research SP-9 MK3 tube preamplifier has been in my system for many years. I had not realized it was speaking with any tube coloration until I compared it with the CV-1. To find out more we need to move on to my ultimate reference the sound of a human voice.

"-- J.K. Rowling, Harry Potter and the Sorcerers Stone, 1997.

Not a new album but a revelation to me. This is a very superior recording of Joan Baez singing the title song, Diamonds & Rust [A&M Records CD3233]. Not really, a fan of her work until I heard this beautiful rendition. She makes me realize just how bad the art of phrasing and lyric interpretation has become. What was made clear to me is she is not just another one-octave female clone shouting to be heard over some amplified backup. This musical arrangement is exceptional; the airy swirling musical accompaniment paints the perfect background to her wistful emotional vibrato. The Shengya CV-1 provides me with a clear pristine conduit full of meaning. You can hear it all in microscopic detail, the longing, the breathy sadness. To me this exactly what a high-end preamplifier must do.

At one of the audio line shows someone gave me a demo disc it is a compilation of 14 different female vocalists. It is: Best Audiophile Voices Selection on the Premium Records label [PR27905]. The following are two excerpts from this album I use as a musical barometer. Track 8, "Marisa", by Dave’s True Story. On this selection once again I am pulled in by a clean clear dimensionality that places the lead voice directly in front of me. There is a clarity that enables me to hear and hang on to her every intake of breath as she crafts each phrase. Gently a deep bass guitar line provides a foundation of chord changes that echo and support the vocal line riding octaves above it. At the bridge a tenor saxophone passage fills my room, each note surrounded by an envelope of echoing air. Wonderful sound, this the way it’s supposed to be. 

Track 13 is titled "When You Say Nothing At All" from the album Alison Krause & Union Station. Alison Krause is what I call a "Head Singer". By that I mean she has crystal clear high pitch but the effect is that she sounds a bit cold and slightly disembodied within her one octave range. Emotional interpretation is lessened because Krause sings mostly off the bridge of her nose. This is not to say that she has a nasal quality. Rather if she would sing using more of her body and diaphragm, she could convey more of the songs emotional meaning. (Think Basia Trezetrzellewska) Another way to say it is she still could hit all the notes and tell us the emotional consequences. There are far to many female singers with a one octave range who sound similar to her. Having said that I still enjoyed this performance. The dual vocal segments the clear lead vocal and back up along with the crisp steel transients of the lead guitar are a testament to the speed and pitch delineation of the CV-1. Through the CV-1, treble extension goes out seemingly without limits defying any stereotypical notions of what vacuum tube limits are.

Because most everything I have told you so far resides mainly in the midrange and treble once again I need to refer to one of my mid/bass reference discs. It is an excerpt from a demo CD given to me at the last Las Vegas CES. The selection is Fanfare for the Common Man by Eiji Oue and the Minnesota Symphony Orchestra. For this segment, I switched to my four-way Onix Rocket Strata Mini speakers. And connected the CV-1 with balanced interconnections to my Sanders ESL Amplifier This very versatile speaker uses an eight inch bass reflex driver powered by a built in 350 watt transistor amplifier.  And it is in this region where we run into a bit of bother, as Pooh Bear might remark. The opening lines of Fanfare consist of bass drum percussion so powerful it could be used to break a tenant’s lease. And it is here dear reader, down at the bass frequencies that the rules of total neutrality are relaxed. Yes, the CV-1 can go down real low and grab all the correct bass notes, but the initial first mille second of transient impact at the drum head, the instant that startles you is missing. The second track on this demo disc is a great recording of Peggy Lee singing Fever. The tempo is a plucked bass fiddle line connecting all the words in Peggy’s signature song. It sounds deep and warm and that’s good but it needs to be a bit crisper to bring it fully to life.

What Is This All About?
Well the big picture as I see it concerns a preamplifier priced way below comparable us lines that is built like a shit brick house. If (and this is relative) it has a failing it is down below where the bass notes go. For me this is not any kind of an issue, tubes are my favorite supply source. I suppose if you are into head banging heavy metal than the CV-1 may not be the way to go. As for me, the inherent value of the CV-1 when everything is considered (quoting Ed Sullivan) "this is really, really a big show". It is worth way more than the price. Considering the great overall build quality, I believe you will have a long and happy relationship long after the honeymoon is over.

Semper Hi-Fi

Reference System
Aurum Cantus Leisure 2 SE speakers, Onix Rocket Strata Mini speakers, Sanders Sound System ESL Power Amplifier. CD Source, Marantz CV8400 Universal CD player.

Accessories: Islatrol industrial 20amp main system line conditioner, also a one-ampere Islatrol transformer in series with a Triad isolation transformer supplying power to all digital components. Richard Gray’s RPG Substation, Alpha Core Balanced power transformer, Audio Power PE-1 Power Enhancer, Ferrite blocks on interconnects and line cords, Room Tunes corner/ceiling panels, and trio of Argent RoomLens, Gryphon diffusion panels, VPI Magic Bricks. Cables, Kimber Kable 12 TC Speaker Cables, Two pairs Monster interconnect cables, Nordost Red Dawn, Audio Research Litzline, Wireworld Eclipse-2, Chord Silver Siren interconnects, Audiobahn 0.5 meter digital, Eichmann series 2 interconnects with "Bullet" RCA plug’s, Wireworld 10 gauge AC power cord, Radio Shack SPL meter, Rives Audio Test CD, and a comfortable chair.

Specifications
Type: Vacuum tube stereo preamplifier
Frequency Response: 20 Hz to 20 kHz (±0.5dB)
Tube Compliment: Nine vacuum tubes (12AX7 and 12AU7)
Rated Output: 2 Volt (in balanced mode)
Maximum output voltage: 30 Volts
THD: 0.1% (1kHz 2V)
Input Sensitivity: 400mV (in balanced mode)
S/N Ratio: 85dB
Input impedance: 47kΩ
Dimensions: 446 x 142 x 415 (WxDxH in mm )
Weigh: 25 lbs.
Price: $3000

 

Company Information
Shengya
Guangdong Zhongshan
Industrial Zone Taohuasha
528415

E-mail: info@shengya-audio.com
Website: www.shengya-audio.com

North American Distributor

Voice: