Review: Coda FET-01p Preamplifier
The genesis of CODA Technologies began in March of 1985. Originally incorporated as Continuum Electronics, an independent design and engineering consultancy, the company was founded by Eric Lauchli, B.D. Dale and Lorin Peterson, former members of the R&D and technical support staff of the Threshold Corporation, then an innovative leader in high-performance solid state audio electronics.
In 1989, Continuum was renamed to the present CODA Technologies, Inc., and began producing its own line of state-of-the-art, reference-quality audio electronics. The first product bearing the CODA badge was the FET Preamplifier 01.[excerpt from Coda]
To me that speaks volumes of outright determination, courage and committment of these former Threshold staffers. To bring to the high end market environment a near $3,000.00 preamplifier as their first product bearing the Coda badge. Few startup companies would have embarked on such an ambitious journey at the time of release of the Coda 01p preamplifier. No doubt they are to be commended for such lofty aspirations. For here you had people that had total faith in their expertise, plus the craftsmanship to produce an extraordinary product that has more than withstood the test of time and continues to impress to this day.
In my opinion the Coda 01p is nothing more or less than a true reference caliber preamp of superb build quality and the circuit board is a true work of art, not often found today or in the past. Parts selection is of very high quality, nothing skimped on here. The overall quality here puts this preamp in very rare company, such as Levinson, Krell, Pass Labs, Spectral and Klyne but to name a few of its peers. I feel more than easy in saying the Coda 01p is a Class A rated preamplifier. I do not know or care what previous reviewers may have rated the Coda 01p. But after fifty years in this hobby/business I feel more than easy in giving it a Class A rating.
However in the final analysis none of the above would matter if the Coda 01p did live up to its expectations. After sometime in my system the Coda 01p fully met and exceeded its expectations as a reference preamplifier.
In music, a coda is a portion of a work that rounds out, concludes, or summarizes what has gone before. Beethoven raised the coda in his sonata form movements to a feature of the highest importance, producing a final section of equal musical weight to the foregoing exposition, development and recapitulation sections and completing the musical argument. I could not think of a better name for a high end company and this their first product truly fits the Coda design and philosophy.
Lets get the obligatory specifications out of the way.
CODA FET Preamplifier 01p Specifications
Frequency Response: DC to -3dB at 200 kHz
Distortion: Less than 0.01% from 10 Hz to 40 kHz at 6 Volts peak into 600 Ohms or higher, shunted by 1,000 pF or less
Gain: 14 dB unbalanced or 20 dB balanced
Maximum Output: 12 Volts peak
Noise: Greater than 100 dBA referenced to 1 Volt output
Input Impedance: 20 k Ohms
Output Impedance: 15 Ohms non-reactive unbalanced
30 Ohms non-reactive balanced
Crosstalk: 70 dB at 20 kHz
Frequency Response: ±0.2dB of RIAA with subsonic rolloff at 14 Hz
Distortion: Less than 0.01% from 20 Hz to 20 kHz at 3 Volts peak
Gain: 37 dB at 1 kHz (low)
57 dB at 1 kHz (high)
Maximum Output: 12 Volts peak
Noise: Greater than 85 dB referenced to 1 Volt output
Input Impedance: 22 Ohms to 47 k Ohms
Crosstalk: 70 dB at 20 kHz
Frequency Response: DC to 1 mHz
Distortion: Less than 0.01% from 10 Hz to 40 kHz at 3 Volts peak into 22 k Ohms
Gain: 0 dB (unity gain)
Maximum Output: 12 Volts peak
Noise: Greater than 100 dB referenced to 1 Volt
Output Impedance: 1 k Ohms non-reactive
Independently regulated with shielded toroidal transformer and 25,000 uF of power supply filter capacitance
Height: 1.75" Faceplate, 2.15" Overall
Width: 19.0" Faceplate, 17.0" Chassis
Depth: 9.75" Overall
Weight: 14 lbs.
Power Consumption: 10 Watts
Independent listening and recording selectors
All FET voltage gain with bipolar current gain
No overall feedback
True DC-coupled design
Balanced and unbalanced outputs
Wide bandwidth regulated supply with AC EMI and RFI line filter
Double-sided gold-plated circuit boards
All anodized chassis
10 year warranty / 5 year transferable
On the front from left to right is the Input selector for Phono, Compact Disc, Tuner, Video, Record 1, Record 2. The Record Selector mirrors the Input Selector. Next to that is the Mode which allows Stereo Reverse, Stereo and Mono. Then the Balance Control followed by the Output Level Control(volume). The volume control is of the non-stepped variety by Alps. That I really appreciate as I find with stepped volume controls, that I always need something in between the settings of stepped volume controls. I usually get to loud or to soft with the stepped controls. For me the Mode Control is a nice feature not often found. I listen to a lot of vinyl and many of the jazz albums released in the fifties and early sixties were Mono pressings. To be able to select the Mono setting on the Coda 01p is indispensible for vinyl mavens.
The rear panel of the Coda 01p features an IEC power cord connector and balanced outputs as well as a full complement of very high quality RCA inputs as well as a ground post for turntable use.
The face plate of the Coda 01p is 9mm in thickness. The entire metal case is black anodised including the face plate. White silk screening on the faceplate for controls.
Inside the case are the adjustments to set phono cartridge loading and gain for MM or MC phono cartridges. Also switching for the balanced outputs to USA standard or European standard. Nice touch there.
Music Used For Evaluation:
Bob James - Hands Down (Columbia FC 38067)
Hiroshima - Self Titled - (Arista MFSL1-525)
John Coltrane - Blue Train - (Blue Note BST 81577)
Wes Montgomery - Bumpin' - (Verve V6-8625)
Rickie Lee Jones - Self Titled - (Warner BSK 3296)
Wynton Marsalis - Live Blues Alley - (Columbia PC2-40675)
Eric Gale - Forecast - (KUDU Records KU 11)(CTI Records)
Kenny Burrell & Grover Washington Jr - (Blue Note BT 85106)
Earl Klugh - Finger Painting - (Blue Note MFSL 1-025)
Larry Carlton - Friends - (Warner 23834-1)
Sadao Watanabe - Autumn Blow - (Inner City IC 6064)
Doobie Brothers - Minute by Minute - (Warner BSK 3193)
Santana - Zebop - (Columbia FC37158)
Pat Metheny Group - American Garage - (ECM 1-1155)
Frederick Fennel - Cleveland Symphonic Winds - (Telarc 5038)
Paul Desmond/Jim Hall - Complete Recordings - Mosaic(MR6-120)
Time Out - Dave Brubeck Quartet (Columbia CS 8192)
Paul Desmond - Self Titled (Artist House AH - 2)
Ahmad Jamal - But Not For Me - Argo LPS 628
Bill Evans - At The Montreux Jazz Festival - Verve V6-8762
Bill Evans - At Montreux II - CTI 6004
Sunken Cathedral - American Gramophone - AG 361
No Bass Hit - Concord Jazz Label - CJ-97
Oscar Peterson - Night Train - Verve V-6 8538
Gerry Mulligan Reunion Chet Baket - Pacific Jazz ST 90061
Ben Webster At The Renaissance (Contemporary Records OJCCD-390-2)
The Royal Ballet Gala Performances (Classic Compact Discs CDSCD 6065)
Jurassic Park Motion Picture Soundtrack (MCAD 10859)
We Get Requests - The Oscar Peterson Trio (Verve 810047-2)
You Won't Forget Me - Shirley Horn (Verve 847482-2)
On Every Street - Dire Straits (Warner Brothers 26680-2)
Trio Jeepy - Branford Marsalis (Columbia CK44199)
Paris Jazz Concert - Louis Armstrong (RTE 1001-2)
Braveheart Motion Picture Soundtrack - London Symphony Orchestra (London LC0171)
Patriot Games Motion Picture Soundtrack (RCA 07863 66051-2)
Highlights From The Plugged Nickel - Miles Davis (Columbia CK 67377)
Private Investigations Best Of Dire Straits (HDCD) - Dire Straits (Warner Bros 49891-2)
Straight Up - Bob James Trio (Warner Bros 945956-2)
Land Of Giants - McCoy Tyner (Telarc 83576)
New York Reunion - McCoy Tyner (Chesky 5173324)
Gladiator Motion Picture Soundtrack(Decca 2894670942)
Copland - Appalachian Spring (Telarc CD 80078)
Frederick Fennell - Holst Suites (Telarc 80038)
Tchaikovsky - 1812 Overture (Telarc 80041)
John Williams - American Journey (Sony 89364)
Bizet - Carmen (Telarc 80048)
Live At Sweet Basil - McCoy Tyner Trio (Evidence ECD 22106-2)
During the week I play about 30 hours of analog. In fact a more precise use would be 75 percent vinyl playback, 20 percent CD use and the remaing 5 percent is Tuner playback.
The phono section of the Coda 01p, is one of the finest on board phono preamps I have heard. Presently using a Benz Micro Gold MC phono cartridge. The Coda 01p has a phono preamp that is so liquid,seamless, with detail and clarity that approaches and exceeds some of the finest stand alone phono preamps in the market place today. To do better than this phono preamp in the Coda 01p, one is going to have to dig deeply into their resources to do better.
The line stages of this preamp are as well explempary in their execution and sonic play back. The CD input is well thought out and the Audio Analogue Paganini CDP I use was a outright joy to hear through the Coda 01p. Many times I thought I was listening to analog, when in actuality I was listening to CD playback. Thats something I was not prepared for, to hear CD without the grain and glare that at times is present in lesser preamps.
The Coda 01p is a true reference class preamplifier whose sonics will leave one truly astounded. One of the quietest preamplifier to ever come through here. The sound just emerges from a graveyard quiet background and at sometimes is breath taking when the music emerges to your speakers. It is equally at home with the newer Digital amplifiers or the conventional Class A/AB amplifiers. Have used it with both types and find zero issues with it. Of course the better the associated components the greater the reward the Coda 01p will give. It will not elevate pedestrian components to another level. But with the given of having components of like quality, the Coda 01p will add that finishing touch to a system, big time.
One can use all the superlatives one has at their command and still fall short in an accurate sonic description of this over the top preamplifier from the gifted minds at Coda. And to think this was their first product, just boggles the mind. If you desire a preamp that delivers crystal clear music with all the nuances assoicated with the musical experience the Coda 01p must be at the top of that list. For here is a preamp that not only promises the high end experience, but delivers that promise time and time again. Listener fatique with this preamp is long gone. This preamp like no other before it has me going through my library rotation of playback day after day, and adding more to my weekly rotation of music to be heard. That's a first for me. After more than fifty years of this hobby/business I am and remain more than a little jaded when it comes to preamps in this lofty category. But this time Coda has delivered a no excuse preamplifier.
Design Philosophy From Coda in regards to the 01p preamp:
The circuitry utilized in your FET PREAMPLIFIER 01 is the result of an advanced and complete design process combining innovation and proven fundamentals. This process avoids both the limitations of total adherence to convention and the flaws resulting from inappropriate application of clever circuit gimmicks. Our approach demands painstaking consideration of every facet of each design choice regardless of how small. Analytical, as well as subjective techniques are all applied in an open-minded fashion with "no compromise" musical perfection as the goal. The resulting refinement of the product escapes simple explanation. With this in mind, we present here a few design highlights and concepts.
All voltage gain is derived from FETs. While careful design can yield good results from any device type, FETs consistently seem to have the edge in voltage gain and interface applications. This is borne out by superior sonic qualities observed in subjective testing. FETs are inherently transconductance devices, meaning that an input voltage controls an output current. In other words, it "senses" the audio signal without drawing current from the source to provide an output. This eliminates complex interactions with the source allowing maximum performance from each system element and greatly reducing the chance of cable characteristics altering the sound. The absence of input current in FETs also allows high bias currents for linearity and speed without sacrificing DC parameters.
While excellent capacitors for coupling use exist, there can be no doubt that a signal path free of coupling caps yields the best possible signal integrity. The DC stability of the circuit eliminates the need for any questionable DC servo circuits or coupling capacitors. We make no AC compromises for DC performance, however. Our key design choices provide not only inherent DC stability, but also optimized AC performance throughout the audio region and well beyond. These choices include the use of top quality dual FETS in differential configurations for all voltage gain. Because the signal in these stages is handled in a balanced manner, rejection of unwanted noise and modulation from external sources is extremely high. This rejection extends even to noise which may originate within the circuit from support circuity such as current sources. Stray RF signals are also rejected well.
In the phono stage where the necessary equalization requires the use of capacitors, we use only high grade film types. These and other equalization components were carefully chosen to maintain response to within .2dB of RIAA standard. An additional subsonic rolloff at 14 Hz serves to reduce 1M Distortion.
Noise is kept low by paralleling input devices, careful selection of circuit impedances, and pre-screening of devices.
The class A complimentary followers used to drive the preamp output are of such speed, linearity, and low output impedance that no feedback correction is required or used. The advantage of this is that the circuit's perfect stability and transient response are preserved into a wide range of difficult and unpredictable loads. Variation in sound which could occur through interactions with interconnect cables and other system elements are thus avoided. A simple, very high performance inverter provides a fully balanced output on the preamplifier which allows the user to take advantage of the
balanced inputs on many power amplifiers. The most commonly acknowledged advantage of this is rejection of stray noise pickup, but improvements in distortion and bandwidth may occur also.
While many manufacturers intentionally omit recording buffers on the grounds of signal path simplification, the potential advantages of their use were worth an investigation. The resulting experimentation ended with the development of a circuit of such simplicity and performance that its transparency was guaranteed. The circuit is simply a direct coupled class A, FET follower. Because of the FETs inherent characteristics, the buffer provides total isolation of the recording system from the main signal. In addition, it provides a relatively high, purely resistive load to the source, and a relatively low, purely resistive drive to the recording system. This assures consistent stability and freedom from interactions, including cable effects.
The requirements of a power supply for flawless audio reproduction are straightforward but important. The supplies in the FET PREAMPLIFIER 01 take a very direct approach to high performance. First a top quality shielded toroid transformer with plenty of reserve current capability is used. The shielding eliminates strong fields which could induce hum into sensitive circuitry. About 20,000 uF of capacitance with very low ESR and inductance provides good passive filtering. A reference voltage is developed by delivering a constant current to zener diodes. The resulting voltage is heavily filtered and delivered to each stage through independent class A followers which completely decouples the stages. The resulting non-reactive low impedance over an extremely wide bandwidth yields a perfect power source for the individual circuits. The simplicity and absolute stability of the supplies removes the chance of unpredictable interactions which may occur with the more elaborate, high feedback circuity often used.
Most companies in the upper end of the audio industry use either sheet metal or formed aluminum. By contrast the FET PREAMPLIFIER 01 has all structural parts made of machined extruded aluminum. The advantage of this over an all stamped chassis is that the machined metal can be worked more precisely allowing us to work on tighter tolerances and use PC mounted parts more easily. Moreover such a design allows easier servicing either for repair or for future upgrading. From the standpoint of appearance, a machined surface can be contoured in a far more precise manner, giving the final product a more seamless appearance.
1. Finishes - All exterior and interior metal parts are anodized. While paint may be more impact resistant the anodized surface is more resistant to solvents and prevents corrosion. Moreover, the anodized parts appearance can be enhanced by either graining or bead-blasting the surface.
2. Circuit Boards - Circuit boards are fiberglass epoxy with gold plating over a tin/nickel barrier. This gold layer will not corrode, while the barrier plate prevents the gold from migrating to the lower copper layer and detracting from its appearance.
3. Resistors - All are highly reliable metal film 1% resistors.
4. Capacitors - All capacitors have been eliminated where possible on the basis that "no cap is better than the best cap." Where they are used in the active part of the circuitry, they are high quality film caps. The only electrolytics used are in the power supply where large numbers provide enormous filtering capacitance for the supply.
5. Semiconductors - There are no integrated circuits to be found in this product. Very high quality dual FETs are the only source of voltage gain and were selected for their superb noise performance and precision matching. The remaining semiconductors are also of very high quality, each possessing parameters ideally suited for the specific application.
6. Potentiometers - The volume controls are conductive plastic. These pots track with little error and are totally neutral.
7. Connectors - Coda employs a standard RCA configuration with a gold plated case. The balanced output connectors are Neutriks from Switzerland. These are black chrome finished with gold contacts.
8. Wire- All signal wire has been eliminated whenever possible. Where wire is used, Coda employs silver plated copper, 141 strand, 18 gauge wire with a silicone insulation.
End from Coda on the 01p Preamplifier.
In the pre-owned market these command prices from $900.00 to $1,200.00 based upon condition, and if box and manual is included. Some of these were released as a line stage only preamp. So vinyl mavens need to be careful here and make sure the one your looking for has the on board phono preamp. However at the pre-owned prices the Coda 01p is an outright steal of a bargain. I have spoken with the staff at Coda and the tell me they only see one or two a year for service issues. That tells you a lot about the build quality of the Coda 01p. Plus the good part Coda remains in business and should service ever be needed they are just a phone call away. An important factor to consider in purchasing used gear, will service and support be there? With Coda that is not an issue to consider. They support previous product with the same dedication as their current product.
I find that there is little in the pre-owned preamplifier market today, at the price point of the Coda 01p, that can deliver the promise and performance of this preamp.
In my opinion this is the Rolex of high end preamps. Understated elegance to say the least. Can one do better than the Coda 01p, sure - but at what costs? Loftier price does not always equate to better performance.
At this point in time I cannot see the Coda 01p not in my system. It has elevated the performance of my system to another level. More than highly recommended by this jaded maven.
PS Audio HCA2, Audio Analogue Paganini CDP, Goldring GR1.2, Benz Gold MC Phono Cartridge, Sony MDS 480, Polk Audio XM Tuner, Belkin PF 60 Power Console, Musical Concepts Interconnects, Audioquest Interconnects, DH Labs Power Cords
Threshold, Levinson, Krell, Spectral, Pass Labs,etc