|Reviewer: Srajan Ebaen
Source: Cairn Fog v2.0 as transport; Zanden Audio Model 5000 MkIII DAC; Furutech Digi. Reference BNC-BNC digital cable; Ortho Spectrum AR-2000 filter/buffer on the DAC's analog outputs
Preamp/Integrated: Bel Canto PRe6 GenII; Eastern Electric MiniMax
Amp: AUDIOPAX Model 88; Bel Canto eVo 4 GenII; Coda Technologies S5 [on review]
Speakers: Avantgarde Acoustic DUO; nOrh SM 6.9
Cables: HMS Grand Finale; Analysis Plus Solo Oval and Oval 8; i2digital X-60; Stereovox HDXV; Mapleshade Ebony active digital interconnect; Mapleshade Planar power cord with DC bias; Audio Magic Clairvoyant power cords; Z-Cable Reference cables and Hurricane and Cyclone power cords [on review]
Stands: Grand Prix Audio Monaco four-tier
Powerline conditioning: BPT BP-3.5 Signature; Walker Audio Velocitor for source components
Sundry accessories: GPA Formula Carbon/Kevlar shelf for tube amps; GPA Apex footers underneath stand and speakers; Walker Audio SST on all connections; Walker Audio Vivid CD cleaner; Furutech RD-2 CD demagnetizer; WorldPower cryo'd Hubbell wall sockets; Musse Audio resonance dampers on DUO subs; Mapleshade 4" solid maple platform under BPT conditioner
Room size: 30' w x 18' d x 10' h [sloping ceiling] in long-wall setup in one half, with open adjoining living room for a total of ca.1000 squ.ft floor plan and significant 'active' cubic air volume of essentially the entire (small) house
Review component retail: $3,950 all-black or black with silver fascia; add $200 for total silver/total graphite (the latter as reviewed, think anthracite)
|That first love of yours - looking back, should you have parted ways, really? In more ways than one, sometimes you need to go back in time to go forward in the present: Perhaps to smack-shut doors to move on; perhaps to finish learning a lesson; or perhaps to take said lesson -- learned already once over -- but reapplying it now with the wisdom of hindsight and accumulated experience?
Coda's new S Series warrants such ruminations. The genesis of the project roots with the past, Coda's first-ever amplifier dubbed System 100. At the time (and still available by custom order), it was/remains the manifestation of a most ambitious wish-list along which to design the best amplifier its designers could dream up, cost no apologies. As with the sanctified digits 7 and 9 in the Marantz bible or the number 1000 in the Nakamichi lexicon, the letter 'S' in Coda's history has remained reserved for the big one - the mucho enchilada, the Kahuna Grande with steam and whipped cream. And it's been lying dormant since. Until now. To paraphrase chief doc Eric Lauchli, "with the S Series, our intent was to revisit everything we love about the System 100 and to bring as much as possible of that magic into new models designed for slightly less demanding loads, using the latest devices, techniques and insights we've developed since."
Regarding those devices. Upon pressing remote flesh and calling in favors, I got marketing director Mark Ward (having read too much John Le Carré of late) to turn coats and spill the following rare Hawaiian beans: "The voltage gain in these amps is provided by an obscure matched dual Mosfet that Coda gave up on years ago because of lack of availability. We chose to go back to this device for the S amplifiers and had to get a commitment from the Mosfet's manufacturer regarding ongoing availability of the part. I think this Mosfet's transfer function helps reveal inner detail while sounding less "ss-like". Eric (Lauchli) feels that Mosfets are best for voltage gain because they are intrinsically ideal for that task -- not to mention their transfer function -- but are lousy for current-gain output duty. That's because of their inherently high and somewhat nonlinear input capacitance for power devices; poor matching between N and P channel compliments; and relatively high and inconsistent output resistance at high currents. This makes designing a no-feedback output stage with good linearity, damping and consistently smooth high-speed performance difficult if not impossible. That's why we stick to this high-speed bipolar output stage. It requires a little higher parts count but we feel it's worth it. Even with the higher parts count -- indeed largely because of it -- the resulting transfer function is actually much simpler and more consistent especially at high speeds. The S Series output devices are much faster than our normal devices. We never used them on higher-power amps because they were limited to 125 Volts. They are now 150V."
What our deep-cover mole with true genteel British understatement forgot to mention, casually calling things a little higher parts count? That the 50-watt rated S5 under review uses a bloody sixty of those 50MHz units, each spec'd at 8 amperes and, yes, 150 volts. That makes for a total of 100 amperes of potential current delivery. Overkill? Ample reserves for true easy-peasy coasting? We shall see soon enough.
If this arms dealer's dream spurs manly man's visions, let's compound it by stating that the amp's power rating cleanly doubles to 100 watts into 4 and 200 watts into 2 ohms. In bridged mono mode, power mongers net 200/400w into 8/4ohms. With XLR and RCA inputs, the S5 allows simultaneous hookup of both, selection made via the front-panel or remote control. Yes, all S-Series amps are remote-capable though the actual SL-9000 backlit and LCD screen fitted Home Theater Master remote is an optional item. It controls bias on/off for standby/go by deactivating bias current in output stage; switches between unbalanced and balanced inputs; and can designate control channels of the amp for independent control in a multi-channel or multi-amp setup.
Further onboard he-man goodies include, no not a mini bar but IXYS fast recovery heat-sinked bridge rectifiers; true DC-coupling; no global feedback; double-sided gold-plated circuit board; independent windings on the 1.5kVA power transformer; dual mono rectification; 72,000 uF supply capacitors per channel; and a total of 60 custom Mills wire-wound emitter resistors sporting pure copper leads and end caps, with a special copper/nickel alloy for the windings as opposed to the more traditional nichrome wire; yet another example of extreme attention to detail. Er - did I just call the lack of feedback he-man? You bet. In situations of conflict, only a truly strong and resourceful warrior can afford to be humble and meek - should it come to it, he knows how to pulverize the other guy's knee cap. In amplification circuits, only a truly superior implementation can avoid feedback without dearly paying for it in inflationary distortion.
Regarding said distortion? The S5 claims less than 0.03% at full bandwidth and full output power while driven into anything between 2 to 8 ohms. That's an honest piece of specmanship - quite unlike that of certain tube amps which, when you arrive at the fine print, are spec'd into 1 watt and merely at 10kHz for a good-looking distortion figure. Bandwidth on the Coda is given as DC to 100kHz, with a signal-to-noise of greater than 120dB. Gain is 26dB, input impedance 50kOhm single-ended, 1kOhm balanced. Output Z is a very low 0.03 ohm at full bandwidth, creating a nominal damping factor of greater than 240. Electrical power consumption is 450w max at full-rated power. Human power consumption to lift its sprightly 45 lbs requires a mere British breakfast of cholesterol-defeating porridge calories (go for the charcoaled meat popsicles at your own risk warns the spy manual). Overall dimensions of the S5 are 17.5" x 5.75" x 12.5".
For increased raw displacement, the S12 more than doubles the S5's output to 125/250/500w into 8/4/2ohms or 500/1000w into 8/4ohm bridged. To achieve this, the S5's full-on Class A bias goes below half-mast for the S12, to 20 watts of precision bias Class A operation before things slide into Class A/B mode (the S5 doesn't slide at all within its 50-watt rating into an 8 ohm load; more on this later). That's why I called the S12 more raw displacement, not a higher level of buff or washboard abs. As my review of Coda-Continuum's Unison 3.1 explored, higher Class A bias does have sonic advantages even if you don't exceed the otherwise comparable Class A/B amp's Class A range. Don't ask me why. It's simply what I heard, even and already with a measly 2-5 watts of output on my 103dB Avantgardes. 'Hotter' Class A bias sounded better. Krell here I come?
For those reckless few for whom nothing but ultimate power will do (get rid of those speakers would be my advice), Coda's new S1 is a permanently strapped, balanced monoblock variant of the S12, delivering 500W into 8 Ohms, with about 20w operating in Class A.. For those who prefer more Class A, Coda can re-bias the S1 for 50W of Class A, with a commensurate reduced power output of 220 Watts into 8 Ohms. These bridged-balanced versions aren't switchable, hence a standard bridged S12 is not the same as an S1 though power output is in fact identical. In Lauchli speak, we learn that this special piece of bridging works by "coupling the front ends in a proprietary way that causes each channel to mirror the other channel's signal. Either input or both can be driven with the same resulting balanced output. The output responds only to the difference of the inputs. Advantages of this method include the fact that the signal path remains as simple and direct as an independent channel, with distortion either staying the same or dropping slightly. Also, both inputs are high impedance and identical. A balanced source can be used to full advantage but is not required for a balanced output."
Translated, this means that the S1 should not suffer the usual decrease of refinement that comes with normal bridging's distortion and noise increase. Note that its distortion could actually drop. In short, with the S Series, you once again get to pick both your output power and how much of it operates in Class A. To take the measure of the massive S1, our own Les-is-more Count Turoczi will follow Mark's example, turn coats, confess to the possibility of more-is-more and report on his findings in a few months. Unlike the English, Les abhors organ meats but absolutely adores his pipe organs. There's nothing that taxes an amplifier quite like shuddering high amplitude infra-sonic signals from 30' organ registers. That makes the S1 into just the sort of chum patient Les needs on his operating table. Today's review shall be more conservative, however, exploring the mere 50 watts of Class A power which the S5 delivers. Did I just say mere? Good grief. How grievously uncivilized of this foggy sod. Flip the page to see him make proper amends.