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Positive Feedback ISSUE 73
CFA-1.2 Integrated Amplifier
Everybody knows what an integrated amplifier is. It is usually a modestly sized component with a volume control and input selector, which is fed with a signal from the source (a CD or turntable for instance) and is used to drive the loudspeakers. The "integrated" in its name informs us that we deal with a pre-amplifier and power amplifier in one box.
The integrated amplifier idiom has two faces, though. One is "Japanese", represented by components from Accuphase and Luxman, and the other is "British", exemplified by products from Naim, Arcam and Linn. The former units have great functionality with plenty of knobs and switches while the latter group are stripped of those extra features sporting only an input selector and volume control. Both have their advocates and it is rather pointless to argue with either of them. The former believe that an integrated should provide its user with the freedom to connect it to any given device and help to shape the sound. The others claim that the only thing that matters is the sound.
For some time, however, there have been attempts to combine those two approaches. Leaving the front panel unspoiled, manufacturers equip their amplifiers with tone, loudness and balance control in a way that is not visible. It has been made possible by advances in microchip development, dropping microchip prices and a lower price of their programming. However, to do it well requires areas of expertise that include both audio and microchip programming.
It is exactly the design concept that was used in the inexpensive Advance Acoustic X-i60 amplifier and in the Crayon CFA-1.2 under review. The CFA-1.2 has been conceived and designed by Roland Krammer, a specialist in the area of microchip programming and a music lover in his free time. While the heart of the unit is a classic bridge design employing MOSFET transistors, here it features a microchip control and is powered by a switching power supply. The latter is really rare to see in audio world. Linn and Chord Electronics have been for years developing their own designs in this field. This type of power supply has also been used for the last two years in new products from Swiss Soulution; whose 710 power amp (still with a linear power supply) has been in my system for two years now. I am not going to dwell on the advantages of either of the two solutions because the end result is really determined by the way it has been implemented. Similarly to the amplifier functionality issue, both camps are equally at odds. I am not saying that both designs give the same results – to the contrary, they differ a lot. One thing, though, is to say that the results are "different" and another is to evaluate them – this must be done in each particular case by the end user, the audiophile. Only his or her own opinion is binding, the rest is just information noise.
A few simple words from…
ROLAND KRAMMER, Crayon Audio – co-owner, designer
My partner and I have been involved with high fidelity audio since early 1980s. The idea for the Current Feedback came to me in 1985 and since 1986 we have been designing pre- and power amplifiers that are based on this concept. But most of the time I earned my money working in industrial electronics business.
The idea for the CFA was born in 2003. However, at that time I worked for a company in Regensburg, Germany. That's why it wasn't until 2006 that the first prototype was physically assembled and could be tested. After a few modifications to the circuit and housing, we had the first 100 units ready in middle of 2007. The next step was finding distributors and dealers, which was not an easy task at all.
Much has happened since the end of 1990s. To describe it briefly, lots of work had to be done with limited financial resources and lots of problems had to be solved. The biggest difficulty was to find the right production and for distribution partners. Then, in 2009, we had the first Srajan's review at 6moons.com. That was the main reason that we took the plunge and transformed Crayon Audio into Crayon Audio GmbH.
The first variant of our amplifier, the CFA-1, was a 40 watt unit. It looked like we were successful. Unfortunately, it turned out that there was a hidden flaw in the circuit board. After many returned orders we slowed down the sales, which also hurt Frankfurter Hörgesellschaft, our first distributor. Initially, we could not find the problem. Nine months of simulations and analyzes did not bring us any further to a solution. If you do not know where the flaw is you cannot fix it or redesign the board. That was our main problem. It was by chance that we eventually found the error. It turned out that it had to do with bad production quality of the printed circuit boards. Well, you should never choose an incompetent PCB manufacturers, just to save a few bucks. The newly launched CFA-1.2 features a completely redesigned board and entirely new electronic components. That's just a beginning to get me going… ;-)
Let me now say a few things about the differences between the CFA-1 and CFA-1.2. Both have been reviewed by Srajan. First of all, the PCB design is completely new. The old board was the main problem. Over time, more than 50% of the old PCBs developed a short circuit between VCC and GND. This time the multilayer boards are made by ILFA in Hannover and the board assembly is carried out by TAUBE Electronic in Berlin. These are small high tech manufacturers that I know well and can rely on. They used to make for us (when I worked for UNITEL) the boards for Pandora International LTD. These were 26-layer PCBs with a 1500-pin FPGA from Xilinx in ball grid array and much more modern devil tricks. The manufacturers built 5 prototypes without any single failure. All worked well from the beginning. Steve Brett could sing a song about this… :-)
The standby power supply now also uses a switching supply. It supports 115 to 230 VAC voltage range, just as the main power supply. We changed the display backlight to amber because white LEDs have a lifetime of only 1000 hours. Amber LEDs can work for 100,000 hours. These are examples of problems facing today's manufacturers. I think modern marketing often hides the truth and we must discover such things by ourselves.
The CD input has now a maximum signal level of +16dBu (for CD players with output voltage over 2V). The gain for this input can now be reduced by -6dB in the setup. The tone control only includes bass and treble control. The reason for that is that the production of the old audio processor from ST Micro system was suspended. But that does not matter anyway since I only use the tone control for the software loudness and the midrange control had no use. I can safely say that the software in the new amplifier is more mature.
The bridge controller has more gain than before. The CFA-1 used to run hotter, as far as we could tell when it sat on a studio mixing console. The sound is now a bit more tangible and lively. We have added some smaller improvements and adjustments that occurred to us over time. These include adjusting the varistors for surge protection. LEDs for mode indication are now plain RED for standby and GREEN for active mode.
The main power supply is now capable of delivering 320 Watt. We use switching power supplies from Mean Well. 10 out of 100 previously used TRACO power supplies failed. In comparison, not a single Mean Well power supply has failed so far. We also added a Pre-Out connector and changed speaker terminals to WBT. From now on, all new CFA amps feature WBT NextGen speaker terminals that additionally accept Banana connectors. That's the current situation with the CFA-1.2, whose development continues.
From the very first generation of our amplifiers we have been manufacturing the enclosures in-house. In the future we plan to design even heavier and higher quality enclosures. We would also like to offer the CFA without the top cover discs and in other color finish, including custom finish. Let me close by saying that the new version of the CFA-1 is now more expensive and sells for $6000 in the USA and €4250 in Europe. I think that would be it for now…
• In The Mood For Love, OST, Wong Kar-wai (director), Virgin France 8505422 8, CD (2000).
• Le Jeu des pèlerins d'Emmaüs, Ensemble Organum, Marcel Pérès, "Musique D'Abord", Harmonia Mundi HMA1951347, CD (1990/2014).
• Art Farmer and Jim Hall, Big Blues, CTI/King Records KICJ-2186, "CTI Timeless Collection 40", CD (1978/2007).
• Bajm, Ballady, Pomaton EMI 8 55988 2, CD (1997).
• Czesław Niemen, Dziwny jest ten świat…, Polskie Nagrania Muza/Polskie Nagrania PNCD 1570, CD (1967/2014).
• Czesław Niemen, Spod chmury kapelusza, Pomaton/EMI PROMO CD 435, SP CD (2001).
• Depeche Mode, Policy of Truth, Mute CD BONG 19, SP CD (1990).
• Diary of dreams, Elegies in Darkness, Accession Records A 137, "Limited Edition", CD (2014).
• John Coltrane, Coltrane's Sound, Atlantic/Rhino R2 75588, CD (1964/1999).
• Marin Marais/Alcione, Suites des Airs à joüer, Le Concert Des Nations, Jordi Savall (conductor), Alia Vox Heritage AVSA9903, SACD/CD (2014).
• Rachmaninoff , Rachmaninoff Plays Rachmaninoff, RCA Red Seal/Sony Music 8697-48971-2, "Zenph Re-Perfomance", CD (2009).
• The Cure, Disintegration, Fiction Records 8393532, CD (1989).
• The Doors, The Doors, Electra/Warner Music Japan WPCR-12716, CD (1967/2007).
• The Pat Moran Quartet, While at Birdland, Bethlehem Records/Victor Entertainment VICJ-61470, "Bethlehem K2HD Mastering Series, No. 20", K2HD, CD (1957/2007).
The first half an hour of the audition was disappointing. Even though I had left the unit switched on for a few hours, the sound of the Crayon was colorless and very light—it lacked midrange body and strong bass. In the next 20 or maybe 30 minutes, the things that were previously lacking came alive. It seems that the amplifier not only needs to be switched on prior to audition (which is obvious) but it should actually be playing. As if without the input signal the output transistors didn't get warm enough to achieve their desired operating characteristics (basic physics, it seems).
As I just said, the amp eventually started "singing". It was a very balanced sound with a slightly favored midrange and upper bass, which was exactly what it lacked the first time around. It brought about very significant changes to the sound that moved towards increased body and density—the aspects I really appreciate in the reproduced sound. Hence, Czesław Niemen's album Dziwny jest ten świat… prepared among others by his daughter Eleonora Atalay sounded in the same spirit as that of the far more expensive reference system. It favored the vocals while the instruments were slightly recessed. Changing to a "gold" record from the Niemen od początku series immediately turned things upside down, showing lots of treble and a rather irritating high reverb. Again, just the way it should be.
The amplifier sounds in a very ordered way. That is why it neatly puts itself in the background when it comes to presenting a certain characteristic of the recording. It is quite obvious that this could be said of any neutral sounding component. But as I have repeated many a time, the neutrality alone, without something extra, without an additional layer, only understood as a LACK of any additional coloring (without any information about, for instance, texture or body) is the road to nowhere. The amp we are talking about behaves quite different. But not "exactly the opposite". It preserves the neutrality and at the same time saturates the presentation to such an extent that it is possible to talk about natural phantom images and very good imaging.
There is a dualism lurking beneath its surface that will be a true discovery and home run for many audiophiles. The amplifier is neutral, there's no doubt about it. On the other hand, it is also "forgiving" when it comes to problems with tonality, selectivity and resolution. It does all these things at once, in one "go" without any sort of "wink wink" at us. This is not the battle between the light and darkness, with the light being a message from the amp's designer about the superior role of truth above anything else and the darkness being poor recordings' quality. This is rather a sort of designer's "negotiating" the end result without any violence.
It works this way: we take a record we know to be a bit harsh-sounding, where the sound engineer wanted to emphasize the sound attack, its "rock" character—let's say Ballady from Bajm. We play it on the Crayon and nice sounding speakers and we get the exact image of what is on the record. But with a "twist". The sound is not aggressive. If we like records that usually create a problem for high end systems, we will be relieved when we listen to the track Małpa i ja from the above album. This is for me the best Bajm track ever and one of the best Polish songs in general. However, its upper midrange and hard treble attack can discourage from listening to it on more analytical systems. Neutrality presumes the presence of analytical sound a priori but the Crayon approaches it from a synthetic rather than analytic end as if it tried to restrain the problems. Listening to Ballady was a very pleasant experience and at high volume levels at that! I will come back to this, i.e. to the ability of sounding unforced, uncompressed. The problems I've mentioned above were smoothed out and tempered. They were still there, just beneath the surface, but they had hardly any influence on the quality of listening. I knew what was going on but I took them to be a kind of "local color", inherent part of the recording. And I kept on listening.
It also works like this: we take a record we know to sound less resolving. Like, for instance, the first digital release of The Cure's Disintegration from 1989. The material was recorded and mixed in analog domain. Hence the AAD (SPARS code) on the record. The tracks are rather dark and not quite selective or even adequately selective. The amplifier from Mr. Roland Krammer did not bring any changes in this department and the sound was still not very open and resonant. But there appeared something else that made up for these shortcomings—a dense midrange and a pretty bottom end. The record sounded great, dense and with gusto.
I believe that Crayon CFA-1.2's combination of neutrality and care for the music material largely results from its extraordinary dynamics and saturated bass—particularly upper- and mid-bass. As I said, the amplifier performs very well when playing loud. It has its limitations, of course, but they are not obvious. The music can be enjoyed exactly as it was recorded, without a sense of congestion or chaos. The amplifier can both provide a backdrop for a conversation and shake the windows. The bass does not extend as deep as with the Soulution 710, no chance, but it is dense and strong. Sometimes it may even seem to be slightly contoured. Not irritating but with a well-defined attack and stronger "surprise" element when the drums suddenly kick in like, say, on the Depeche Mode single Policy of Truth mastered by Nimbus Records.
This goes in hand with great imaging. I am talking here about space and the way the instruments are presented in it. The amplifier tends to build deep soundstage with a recessed foreground, especially in the treble department. It might be part of a greater plan to present problematic recordings in such a nice way—I don't know. But the end result is just as described. At the same time, the Crayon is one of the few amplifiers capable of building such a great, clear and deep on-axis soundstage in front of the listener. It gives breath to the music, opens it behind the speakers and revs up the dynamics.
The amplifier does not present tangible and dense phantom images that were "boosted" by the sound engineer and put in front of the instruments on purpose. This is often the case with jazz recordings from the 1950s. The Crayon makes it evident that it is the vocal (for instance) that is the lead element since it has the biggest volume. But it is not as substantial as from the reference system or from the recently reviewed Jeff Rowland Continuum S2. The American integrated "creates" the sound in its own way by softening it and rounding off its attack. The presentation is warmer; the amp does it perfectly but shapes it in its own way, bringing the foreground to the surface.
The Crayon takes a careful approach to the music material, which is in many instances reminiscent of the Lavardin IT-15. The French amplifier, created for the manufacturer's 15th anniversary, accents the vocals and makes them slightly warmer but at the same time is as just fast and clear as the CFA-1.2. The Austrian unit is clearer and more open, while being more dynamic than both the Jeff Rowland and the Lavardin.
I did not try it myself but I know from other sources that the Crayon amplifier under review has an excellent phono stage. I find this easy to believe, based on what I heard from the digital sources. This is a very interesting example of an amplifier which is at the same time neutral sounding and yet full of "human" element. Its unassuming enclosure does not suggest so powerful and dynamic bass nor such good dynamics overall. It allows for listening to music at very loud levels, regardless of the recording quality (to a degree—let's not get carried away…). The listener attempts to understand music with it, easily forgetting its "form" i.e. the mechanical nature of reproduced presentation.
It is not ideal. It does not saturate the foreground the way I am used to, nor does its bass extend as deep as on my Soulution 710. Compared to other amplifiers in this price range, it is perfect and makes for a "required read" in an audio salon, even if only for educational purposes. It cannot be called "the best integrated amp," though. This title still belongs to the Soulution 530—a ten times more expensive (almost, but it sounds better this way, doesn't it?) monster from Switzerland. Neither is the Crayon warm enough to appeal to tube aficionados. Not that it lacks anything in this department but it does not pretend to be something else than what it is. And, last but not least, it does not show such a large image volume as all the above mentioned integrated amps.
The thing is, it just cannot do that. Its limitations are inherent to its design and price level. As long as we understand what we get, we can ignore the nagging thought of it being "the bestest". What remains is comfort and breath, and the certainty that the device does not lie or add anything to the presentation. And the pleasure of listening to music without irritation or nervousness. When we add to that its great functionality and interesting looks, it could become OUR amplifier.
I am not worried about selecting matching speakers—this amplifier will handle most designs that are available on the market. One thing that is worth considering, however, is that the manufacturer has traditionally showcased their products together with Trenner & Friedl, whose Pharoah speakers we reviewed HERE.
This is a sleek, compact unit. Its entire enclosure is made of aluminum plates bolted together. On the one hand, this protects the electronic circuits against external EM noise and, on the other, it ensures that they operate in the best possible mechanical conditions. The thick enclosure walls provide very good vibration damping, especially if the assembly is as compact as here. The isolation feet serve the same purpose. They look like "pillars" clasping the enclosure from the top and bottom. The feet, large aluminum discs, are their bottom parts. The upper discs feature milled out recesses that can support the feet of another Crayon component. Together, they form a kind of anti-vibration "rack". A similar design is used by the British manufacturer Chord Electronics.
The Crayon sports an interesting cooling system for power transistors. Instead of conventional heat sinks, it employs a rectangular aluminum bar mounted vertically across the whole chassis length with eight 24mm chimney bores and matching holes in the bottom and top panels. We have recently seen this type of cooling in the amplifiers from Dan D'Agostino, although they used external copper cooling components (see HERE).
The designers were very keen on a modern looking and aesthetically pleasing amplifier. Its front panel is hence nearly devoid of any controls. It only sports five large buttons that are flush with the faceplate surface and orange display. The buttons are used to change the volume and select the active input and turn the unit on or off (from standby). The display is mounted in a recess in the front panel. It is not too large, which is a pity. It shows two lines, with the current input displayed in the top and volume level in the bottom one. The latter can be displayed either as a bar graph or alphanumerically. The front display is also used for accessing the setup menu. Since the CFA-1.2 is a very modern audio device with microprocessor control, it presents the user with a lot of extra features. Roland Krammer - chief designer and Crayon's owner - previously worked as head of technical department for Unitel GmbH, technical assistant for Presens GmbH, Infolog GmbH and Syrinx DSPC GmbH, and head of development for Micro Analog GmbH. His CV is impressive.
The Crayon's extensive setup menu can be used to:
• set individual input gain between -6dB and +18dB, in 2dB increments
• provide tone control for each individual input; low frequency (100Hz) between -14dB and +14dB in 2dB steps and high frequency (12kHz) with the same parameters
• adjust the balance between the left and right channels (in 1dB steps)
• select the type of cartridge for phono input (phono input gain) - MM or MC
• activate the loudness control
• customize the loudness control depending on the connected speakers' sensitivity (see below)
• adjust display contrast
The speaker efficiency (sensitivity) setting is not associated with the amplifier gain. It is based on the "intelligent" software-driven loudness control that boosts the bass at low volume levels. As is known, the sensitivity of the human ear changes as a function of frequency and volume level, with the ear being most sensitive between 2 and 5kHz. To achieve a flat listening perception curve, low and high frequencies require a significant boost at low listening levels as compared to the midrange frequencies. The "loudness" control alters the frequency response curve, boosting the bass and treble, to correspond with the equal loudness characteristic of the ear. The Crayon only features a bass boost that is carried out in two steps, first by 2dB and then by 4dB. The application point depends on the speaker efficiency setting in the menu. For example, with the speaker efficiency setting of 88dB the first point is at a '45' volume level, and the second at '36'.
The amplifier thus offers outstanding functionality. I only wish all those settings were shown on a larger display so that the user did not need to squat in front of the unit. Even this display could be used more efficiently if it showed the current setting (e.g. source and volume) in both lines, at least for a moment. This is how it's done by other manufacturers, like Marantz.
The display goes off after a few seconds to minimize noise artifacts. It is activated again after pressing any button. This is indicated by an adjacent LED, which shows red when the amplifier is in the standby mode and green when it is powered on.
What immediately catches the eye on the rear panel are very good speaker terminals from WBT. The exact model used is WBT-0708 Cu NextGen, with minimum size metal parts made of pure copper. You may remember that this "revolution" was initiated by Keith Eichmann in his BulletPlug RCA connectors. Shortly afterwards, WBT came up with a similar solution, and the new series was called NextGen.
Line inputs look ordinary and use typical gold plated connectors soldered directly to the board. They are quite close to one another so it may not be possible oversized RCA plugs it is to completely separate some. There are three line inputs and one phono input. Adjacent to the latter is an extra pair of RCA connectors to plug in RCA adaptors with internally soldered resistors and capacitors for proper cartridge impedance matching. Exactly the same solution has been used for a long time by Ayon Audio. Other connectors include Rec-In/Out and Pre-Out. There is also the usual IEC mains socket with rocker power switch and two fuse sockets.
I have already mentioned it so it should come as no surprise that the amplifier runs off a switching power supply. It is manufactured by Mean Well in China. This company, founded in 1982, is one of the most respected switch-mode power supply manufacturers. The power supply is fully shielded in an aluminum enclosure to protect the audio circuits from significant RF noise that is inherent to such designs. It has two separate DC lines (for the left and right channels?) that are fed to a motherboard located on other side of a rectangular aluminum bar, acting as a heat sink for the output transistors and a RF noise shield.
The motherboard houses all electronic circuits and is densely populated mostly by SMD components. Its trace resistance is below 1 ohm. The multi-layer boards are manufactured in Hannover by Ilfa and assembled in Berlin by Taube Electronic.
It appears that the circuit is fully discrete. The output stage employs four complementary MOSFET pairs from Fairchild Semiconductor Corporation (FQP65N06 + FQP27P06). They operate in a bridged mode, with the current feedback. The amplifier does not have a global feedback loop; only local feedback is used. Signal attenuation is carried out in the ST Microsystems TDA7440 controller, which features both a resistor network and tone control. The manufacturer refers to it as "audio processor". The attenuation can be adjusted between 0 and -80dB, in 1dB steps. Speaker outputs are not relay-operated. Any switching and turn-on transients are muted by soft-start circuitry.
Based on Roland Krammer's tech talk for the "6moons.com" magazine, the amplifier circuit is related to designs from the Swiss Goldmund and Job amplifiers whose core circuit is based on a prototype Tektronix oscilloscope (see HERE). Another important trail were designs from Bakoon (see HERE).
Technical Specifications (according to the manufacturer)
Price (in Poland): 18,900 PLN
Made in Austria