February 2012

World Premiere!
Roger Sanders Preamplifier
Resolving micro detail from a music and painting it beyond the outer edges.
Review By Ron Nagle

  The fall/winter weather five thousand and a half feet high in the Rocky Mountains offers crisp clean air, low humidity and pristine pale blue skies.

The sound was as I hoped; music filled the room and seemed to energize the air in a way different from any driver driven source. Serendipitously this visit coincided with the début of a new Sanders Preamplifier. Prior to this show Roger Sanders offered two separate components, a Line Preamplifier and a Phono Amplifier. This new component is a preamplifier with a phono stage; it has no model number because it replaces the two older components. It remains now as the only Sanders Preamplifier in their line.

Note: There was a time when describing how a thing like an audio preamplifier worked was fairly easy, those days are gone. Now we can find audio components that have single controls that can perform multiple functions.

Description
My review sample arrived broken in and came directly from the Sanders demo room at the Marriott Tech Center. The chassis body is constructed of black painted sheet steel. The overall appearance is that of a low profile rectangular box. The box measurers, 2.5" high by 17" wide by 10.5 "deep and weights 8 pounds.   

The Sanders Preamplifier is available with two different front panels made from 3/8 inch thick aluminum stock.Choose either a black anodized fascia or the version I received that has a brushed satin aluminum face. At the center of the front panel is a horizontal elliptical depression that compliments the design of the Sanders line of power amplifiers.  Within this elliptical (scooped out) depression, there is a line of seven source/input select push buttons. They are labeled from left to right, Balanced (input), Phono, CD, Video, Aux, Processor (loop) and a very unusual Mono select function. This function is useful for checking phase and channel balance. A blue LED lights up just above each of the five main push buttons when one of these sources are selected. Continuing to the right side of the front panel is an elliptically shaped blue LED display containing a two digit numeric readout. Scaled in decibels, this two-digit display normally indicates volume (main) for the source you have selected.

Starting at the left side of the front panel there is an unusual multi function volume control. The shape of this control reminds me of a dresser draw knob.  When the volume control is turned, it feels as though it has soft detents. Each detent represents a one-dB change in volume with a maximum range of one hundred Decibels. This control is unique in several ways. It is actually a three function optically encoding volume control sent to a microprocessor. Unlike a mechanical control, it does not have stops when rotated either fully clockwise or counterclockwise. The first function of this control knob is as a standard two-channel volume adjustment. However, this same control knob performs two additional and separate functions. These are indicated by the words, "Main-Left-Right" (channels). When the knob is pushed inward, you can lower the level/gain of the left channel. A white LED to the left side of the two-digit decibel (gain) display will indicate when this function has been selected. A second push of the same knob will allow you to lower and adjust the right channel volume level as indicated now by a red colored LED. This channel adjustment can also be used to shift and center the performance between the speakers by lowering the volume of the louder channel.

Let us say you want to lower the right speaker and by so doing move the soundstages center a bit to the left. To get to the right channel you will need to push in the volume control knob two times. When you start out the display will read the decibel level of the right channel as double zeros. The red led comes on to indicate you have selected the right channel adjustment. Now turning the control knob counterclockwise will decrease the right channel gain. The readout will change from the zero starting point to a minus (-) decibels number. The thing to remember is by pushing in the control knob once and then a second time you can access first the left and then the right channels separately. However, adjusting the level of each source input is done differently. Specifically, to adjust the level of a source input, you must press the appropriate source button simultaneously. Following this procedure will allow you to equalize every separate input source to play at the same comparative level. Then you will be able to change the level of that input up (by as much as 18 dB) or down (by as much as 99 dB) to get it to match the levels of the other inputs. Remember the loudness for both stereo speakers is controlled using the volume control knob just like any standard two channel potentiometer.

At The Back Panel
We see a line up of eight pairs RCA female jacks. These correspond to the sources selected by the eight front panel push buttons. Additionally, and a very welcome addition are pairs of balanced XLR input and output connections. Listing the connections from left to right, they are The IEC power cord socket, a fuse holder, an AC power on/off rocker switch.  Farther toward the right we find the Output connections, these consist of a pair of right and left XLR balanced output jacks, in addition, there are two pairs of RCA outputs that can facilitate system bi-amp'ing. What is unique is the fact that you can feed my Sanders power amplifier simultaneously with both balanced and unbalanced preamplifier interconnects cables. In fact, whether you use either cable connection separately or both at the same time makes no difference.

The volume control adjusts the levels of all the output connections simultaneously with one exception. There is a processor button that toggles between a video processor and whatever main input is selected. Therefore, you have one set of unbalanced fixed level outputs available. These can be used to feed a recording device or digital processor. This processor input is a special "Pass Through" device at unity gain; the volume control has no effect on it.  Whichever input you select will appear at this processor output and can be recorded. You can use the level control to adjust the loudness of the preamplifier system without it affecting the recording level.

Farther to the right are the Input connections. These are pairs of Gold Plated RCA female jacks labeled: Out, In, AUX, Video, CD, PHONO, and one pair of XLR connectors and lastly a chassis grounding lug.

Not Least
The supplied Sanders remote control is one helluva over kill remote. You can program the MX-350 Universal Remote Control to control almost every component in a complex audio video system. It has a full numeric key pad along with all the functions you would need to control a television set CD and DVD player and most cable boxes. Lucky for Moi I only have to tell you about the part that controls the Sanders Preamplifier. At the business end of the remote control, there is a Liquid Crystal display. The display consists of eight pages, the first two pages are devoted too the preamplifier functions. Page one, at the top is the word AUDIO below that is a list Of the input functions. In order they are, Balanced (input) Phono, CD, Video, Balanced (left, right speakers). Page two, Aux, Processor (video) Mono. The last two functions on page two of the remote are, Ampon and Ampin. The owner's Preamplifier manual does not describe these last two selections neither does the separate instruction booklet that accompanies the remote control.

The Engine Inside
The one and only main printed circuit board covers ninety percent of the chassis interior. It is extremely neat, logical and economically designed. I can see sets of Op-Amplifiers and switching relays positioned near each of the rear panel jacks. Selecting one of the front panel buttons will activate the corresponding relay and deactivate any other. As is usual, the right side holds the component power supply, transformer, rectifiers and storage capacitors.  At the left side of the main board, there is a circuit, which allows Phono Cartridge loading adjustments. I wanted to put this cartridge optimizing circuit to a test because I had just received my rebuilt Blue Point Special cartridge back from Peter Ledermann at the Soundsmith Company.

This is a Sumiko Blue Point Special with a solid ruby cantilever and Microridge diamond stylus. Eventually, that is after a few hours and a break to rest my weary eyes. I managed to position a nearly transparent Ruby cantilever and an invisible diamond where they should go.

Thank you Jim Fosgate for your wonderful Fozgometer!

The Diagram of the cartridge loading circuit looks like this.

There are DIP switch adjustments to vary the amount of resistive and capacitive loading presented to the cartridge. The circuit is dived into two halves, Right Channel and Left Channel. The first adjustment would be to select either High Gain or low Gain to match the voltage output your cartridge. In my case, I chose Hi-Gain to amplify the output of my Sumiko moving coil cartridge.  The next step is subjective, using this circuit will adjust the sound of any cartridge however, this is done by ear and may vary according to your personal preferences. And it may not agree with the specifications provided by the manufacturer. In the diagram above, I added small arrows to show the ON positions of the DIP switches I chose. By trial and error, I set both channels of my moving coil cartridge at 1,000 pf. and 1000 Ohms. Lastly, the manufacturer suggests you leave the preamplifier on to prolong its life.

To Ear Is Human To Forgive Fatigue
Sitting down to listen, my very first ear felt impression is one of a very clean and transparent sound with frequency extension without any limitation. To better illustrate my point let me describe my primary test CD. The main purpose of this CD is a test of sound field detail resolution/retrieval. I use the recorded sound track from the Las Vegas show LOVE [Capital EMI 0946 8 79606]. It is the Cirque du Soleil performance to the music of the Beatles. The very first track on this disk is a remix of the Beatles song Because. At a very low level buried deep under the crystal clear vocal track are the faint sounds of life. At intervals through out the recording, you can hear sounds made by birds, the sound of wings flapping, Doves cooing. Only 32 seconds into the track, you will hear a bird chirping. At 54 seconds Doves cooing, and then at 106 seconds we get to the killer resolution cut. Faintly and now at an even lower volume there is the faint buzzing sound of insect wings. At first it sounds like a Bee but resolution will reveal it as a Fly. Now if you listen using the cutting edge of the audio art you will not only hear it you can follow its flight. Starting just inside the right speaker the Fly quickly moves in a receding diagonal direction across the center stage ending far field behind the left speaker. The Sanders Preamplifier lays it all out there for you to hear, the lateral stage is wide and surgically precise.

Let us inject the human factor; my reference has always been the sound of a human voice, because this I know intimately. Let's listen then to Eva Cassidy, if you look for human emotion turned into music this is the place to go. The first track is the Sting song Fields of Gold, from the Songbird [CD-G210045]. Her words convey a breathless plaintive pleading and longing for a time that has passed. The detail is such that I can pick out the sound of the strings from two different guitars. The sharpest transients are obviously from steel guitar strings. Less obvious is the signature sound of Nylon strings from a second guitar. The strings transient attack and the warmer harmonic overtone reveal the resonating wooden guitars. It is all cutting edge detail and emotion clear for you to hear.

The Phono Stage
It was with a strong sense of curiosity and anticipation that I began this part of the evaluation. The following narrative details the results after a meticulous set up of my moving coil cartridge. A wonderful opportunity presents itself with the Sanders Preamplifier. It is the ability to alter the response of your cartridge to optimize your entire systems strengths, the bass, treble and midrange response. This is what this audiophile hobby is all about. Of course, it is vital to get cartage-loading spot on. However, the end result is like selecting a fine wine the sound must complement your pallet. At random I pulled out a Japanese vinyl pressing of Judy At Carnegie Hall, Capitol Full Dimension Stereo [ECS-40207-08]. Recorded Live April 23, 1961.

From the first few bars of the opening overture, I could hear that the Carnegie Hall space on this recording was huge. I realized that my four way AV Strata Mini speakers could not reproduce the expansive stage width of this classic recording. Of necessity I swapped out the speakers with a pair of two way Aurum Cantus. Leisure 2SE Monitors. Sitting on top of these stand-mounted speakers are a pair of Mark Daniels Omni Harmonizers. These are an add on tweeter with a 360 degree dispersion pattern and a frequency response out to 40 kHz. With the added treble extension, the effect will push, back all of the room boundaries.

The transformation was complete; my room now holds Carnegie Hall and Judy Garland. All of the micro details of Judy's signature lisping pronunciation and taunting timing are with me again. The scale of this performance is wonderful. You hear a tiny figure inhabiting a vast space controlling it all with an impossibly huge voice. On the track The Man That Got Away, you can hear Judy's lips quiver with sibilance when she pronounces the word, away. The audience anticipates her every word and she plays with them and teases them as she delays a breathless millisecond between words. She holds the gathered throng in rapt anticipation at every pause; they hang, lips moving, waiting for the next phrase. I shake my head once again remembering the incredible performer she was.

CODA
So what about the innovative Sanders Preamplifier? It is in every respect a thoroughly modern cutting edge audio preamplifier. I did not utilize, the Audio Video, recorder/processor pass through. This circuit is at Unity Gain and bypasses all of the internal controls; it is essentially just a straight wire that has no sound of its own.  The active circuits of the Sanders Preamplifier have a stunning ability to resolve every micro detail from a music source and paint it beyond the outer edges of my speakers. I was able to clearly resolve differences I made with every component, cable swap, tuner, CD and Vinyl recording. Even moving the preamplifier to sit on three high bounce balls I got out of a gumball machine made a slight improvement. My intention is to convey performance not in technical prosaic but rather to tell you the way the music flows through the Sanders preamplifier and its ability to touch your emotions. I hope I got that across, not inexpensive but the state of the art is never cheap. Highly recommended.

Semper Hi-Fi

Reference System
Source Components: SOTA turntable with Grado Signature tone arm and Blue Point Special moving coil cartridge, Marantz 8400 Universal CD, Player, ART  DI/O Up sampling D/A and A/D processor, Magnum Dynalab FT 101a and Dynalab Signal Sleuth.

Amplification: Sanders Preamplifier, Audio Research SP-9 MK 3 Preamplifier, Sanders ESL Power Amplifier.

Speakers:  Onix Rocket Strata Mini and Aurum Cantus Leisure 2 SE two way monitors on 24-inch stands.

Speaker Cables: Kimber 12 TC

Interconnect Cables: Monster Reference 4 pairs, two-˝ meter, 1 meter and 1-˝ meters
Nordost Red Dawn, 1 meter
Wire World Eclipse-2, 3meters
Audio Research Litzlink 2 pairs, 1 1/2 meter
Chord Silver Siren, 1 meter
Home made Teflon 1 meter
Audiobhan ˝-meter digital

AC Power: Islatrol Industrial 20 Ampere ac line conditioner
Richard Gray 20amp Sub Station
Alpha Core Balanced Transformer Power Supply
Audio Power PE-1 power enhancer
Triad 2-ampere isolation transformer

Accessories:

Specifications
Type: Solid-state stereo preamplifier with phonostage
Frequency Response: 5 Hz to 200 kHz (-3dB)

Inputs: Five unbalanced inputs at line level using RCA connectors. One balanced input using XLR connectors. One unbalanced, RCA phono input with switchable gain, adjustable input loading, and RIAA equalization. One unbalanced video processor input with fixed level at unity gain for "pass-through" use.

Outputs: Two pair of adjustable, unbalanced, outputs at line level using RCA connectors. One pair of adjustable, balanced, outputs using XLR connectors (Pin 2 "hot"). One unbalanced, fixed level output at unity gain for recording using RCA connectors. All outputs may be used simultaneously.

Phono Input Impedance: Adjustable between 47 kOhms and 100 Ohms.
Phono Input Capacitance: Adjustable between 50 pf and 1,200 pF.

Company Information
Sanders Sound Systems
12054 Deer Trail Road
Conifer, CO 80433

Voice: (303) 838-8130
E-mail: Roger@sanderssoundsystems.com
Website: www.sanderssoundsystems.com