11 February, 2012

Review: Kondo Ongaku + KSL-M7 System Part III

Kondo M7 in company with JC Verdier, Leben and Brooks; Ongaku in the background; click to enlarge.

Review: My Kondo System Part III
Kondo Ongaku + M7 System Part III - Digital Playback
Review: Sony CDP-R1/DAS-R1
Review: Audio Note DAC-2

Review: Genesis Digital Lens
Review: Gotham 10070 Coaxial Digital Cable

 

(Last revision Jan 23, 2015 - addition to the AN DAC-2)
(Extensively revised Feb 16, 2012)

Editor's Note:
I'd like to also refer you to a six-year old discussion thread dedicated to Kondo in the most well-known and worthwhile Hong Kong hifi forum called review33; the thread is humorously named AudioNote Ongaku - I'm in pain!, you get the idea! Although the webpage is in Chinese, most write in English, and there are useful information on Kondo buried there. I don't write much there but I do know (of) some of the regulars, all Kondo old-hands. Note there are two arrows on the upper right hand corner which usefully let you reverse the chronological order.

Recently, a part-Kondo user from Scandinavia found the review33 thread and asked about the use of Ongaku as amplifier and matching with preamp. It is a worthwhile question which has not been addressed comprehensively on the internet. The question coincided with my recently re-initiated effort to tune-up my Kondo system. So I have decided to explore his question while tuning up my system. This article is the first of my experience, and more would be forthcoming. First, I'd like to introduce my Associated Equipment for this Round.


Two Digital Systems
Personally, particularly when exploring something serious, I like to play with different sources, be it digital or analog. Contrary to popular belief, digital is still more complex than theoreticians/CAS/Perfect-bit people make it out to be. While digital replay standards have improved in general, all the theories and latest "advances" are often (like digital itself) merely number crunching games that get you nowhere. It still holds true that a good digital playback medium depends heavily on the ears of the designer. There are good sonic reasons why the best of the older products are still being cherished and sought after by connoisseurs (which the head-fi crowd shall never be).
There is a reason why some designers like Thorsten Loesch (now of AMR) still see greatness in the 16-bit TDA-1541 chip! Of course, "perfect-bit" or not, digital has yet to hold up to analog!

Aside from WE, perhaps nothing is more serious than Kondo, and a proper evaluation should be multifaceted. Mine uses older equipment that to me have retained their allure, in many aspects trumping their much more modern yet soul-less counterparts. And the two different sources differ markedly in gain, which proves to have relevance.

Digital System 1 This utilizes the superb Sony CDP-R1 as transport, and its matching DAS-R1
(16-bit TDA1541A; normal output level ~2V) as DAC (full pic at bottom of article). Connection is by the proprietary Sony Twin Link. I have previously written about this venerable system here. I'd like to add that subsequent evaluation has confirmed the greater, indeed exceptional, dynamic prowess of the Twin Link, and the connection is used as one of my references, particularly in replay of big complex music. Of course, the 16-bit TDA 1541A still reigns supreme in reproduction of the hall sound, and subtlety in integrating the whole sonic fabric. If there is a fault, it is that the Sony is a little too smooth, rounding out the edges of rhythmic figures.

L, AN DAC-2; R, Genesis Digital Lens.

Digital System 2 This system is more complex. It still utilizes the same superb Sony CDP-R1 as transport, but is more complex downstream. It uses the more conventional RCA digital output of the CDP-R1, which is connected to:

Genesis Digital Lens Over the years, the Genesis Digital Lens, an old anti-jitter system if you will, has stayed in my system. Its 5 inputs and 3 outputs offer infinite connectivity, and more often than not, even with modern DACs with supposedly top-class jitter-reduction, it improves the sound by firming out the contours. In some combinations, a mild deleterious effect of a little dryness can be detected. In this system it is connected via the same Gotham 10070 to the:

Audio Note UK DAC-2 My DAC2 is an older version, which employs the great-sounding 20-bit Burr-Brown PCM63P; it uses minimal digital filtering and I/V conversion unusually deploys interstage transformers; output via 2x 6DJ8 is fully tube-based, run in SRPP configuration. The output is significantly higher than normal, much higher than the standard 2V; see below). Here is Peter Qvotrup's philosophy and I quote some official descriptions on AN DAC's of the time:


L pic: inside the DAC-2; note the PCM63 and tranformer I/V; click to enlarge.


"...Audio Note waited until 1993 to introduce their first DAC because we felt there were serious problems with the digital format. Only after years of research did we feel we had developed significant enough insight to create a converter that moved the design goalposts forward. We wanted a DAC that would remain state of the art and retain its value for many years. To this end, Audio Note digital products now represent the most original and effective solutions to the design of digital circuitry and to the digital to analogue interface. In digital our approach is the same as it is in analogue; keep it simple and gentle and employ the highest quality components. The digital signal should also be handled with great care. Less processing; treat the original bitstream as fundamental truth.

Our goal is to create a line of classic D/A converters. We started by reducing the digital circuitry to its absolute minimum level and selecting the highest quality (and highest cost) digital chips (i.e.. the Burr-Brown PCM-63, K-type). Then we developed a battery of tests that allow us to further select higher quality chipsets. We do five separate tests to grade our D/A chips and reserve the very finest chips for the DAC-4 Signature, DAC-4, DAC-3 Signature and DAC-3.

In front of the D/A chip most companies use a high-order, "brick-wall" filter to "erase" frequencies above 20KHz. These high-order filters create resonant back waves (ringing) that result in energy reflections that add mechanical artifacts and hardness to the musical signal. This filter is the most critical juncture in a digital based system and how the signal is handled, how the energy is transferred, at this point will make or break a high quality system. Multi-pole filters are subject to ripple in their passband and poor transient response. Additionally, the high-Q ringing causes irregular and uneven dynamic and transient behavior, resulting in hardness, opaqueness, diffusion, exaggerated high frequencies and a false sense of detail. Additionally, the brick-wall filter is one of the primary causes of listening fatigue. Brick wall filters make music sound canned and artificial. Audio Note's solution to this problem was to use the only filter that does not ring or suffer transient or phase problems; a first-order, single pole. This simple filter employs a very high quality 1:1 interstage transformer. This original (patented) strategy gives our digital to analogue converters a very real musical advantage. This unique interface strategy allows the best type of energy transfer. Again, Audio Note has worked to preserve the original proportions and energy distribution of the music signal. Audio Note believes the signal must not be manhandled or subjected to unnecessary manipulations. The simple 'transient-perfect' single-pole filter/interstage transformer combination is the gentlest way to bandpass limit the output of a digital/analogue chipset.

The sonic benefits? Audio Note DACs have an uncanny sense of musical continuity; the listener's awareness of tempo and musical flow are distinctly enhanced. Their retrieval of small scale detail and timing information is second to none. These DACs can only be compared to the best analogue not other DACs.

All Audio Note DACs use the 6DJ8/6922 dual triode, except the DAC-4 Signature which uses the 7119/7044/E182CC. As you move up from the lowest priced DAC-1 to the higher priced DAC-4 Signature the parts quality improves with the DAC-3 and above using AN silver wire. The DAC-1 uses Audio Note Aluminum foil, paper in oil capacitors and copper wired interstage transformers. The DAC-2 is similar to the DAC-1 except that it uses either a 1:1 or a 1:2 interstage transformer for higher output and is designed to drive the Audio Note power amplifiers directly. Maximum output on the DAC-2 is 10VAC. The DAC-2 also has a higher quality component selection. The DAC-3 takes the parts quality to the next level with the introduction of a higher quality interface transformer, a higher grade of PCM63P chip and a more careful component selection. The DAC-3 uses AN-V Silver interconnect between the digital and analogue sections and between the analogue board and the output jacks. The DAC-3 Signature would be the best DAC in the world, were it not for the DAC-4 and DAC-4 Signature The DAC-3 Signature has even more and higher quality Black Gate caps, silver interface transformers, and a individually adjusted silver filter coil. The PCM-63s (K-type) are critically selected and auditioned especially for the DAC-3 Signature. The 4-Series DACs push that critical selection a step further with regard to the PCM-63s. In the DAC-4 Signature these chips are further selected by audition with musical program. The DAC-4 Signature uses the highest grade Black Gate caps, AN-Vx silver wire, and selected copper foil paper in oil coupling capacitors. The Production of the DAC-4 Sig. is generally VERY LIMITED due to lack of suitable chip sets, so delivery time can and should be expected.



The DAC-4 uses separate power supplies for the digital and analogue sections. The DAC-4 and DAC-4 Sigs. both are built on heavy, pure copper chassis. The DAC-4 employs still further power supply and parts upgrades over the DAC-3s. The DAC-4 Silver Signature is our current 'statement' DAC. It has a very improved, tube rectified, choke filtered power supply, the very best Black Gate Caps and Audio Note silver-foil, paper in oil, coupling capacitors. The exotic, E182CC/7044/7119 tube, used in the DAC-4 Signature, brings a greater sense of transparency and power to music reproduction. These DACs are designed to give at least a decade of analogue-like musical enjoyment. Jonathan Valin described the DAC-4 Signature in Fi magazine as "the best there is at any price"...".






Audio Note UK uses the exact same circuit for all of their DAC's, but the higher grade ones have "better parts" and tube rectification. As you can see from the pic, the DAC-2 is very well built. I agree (see descriptions below) the sound is much as the official literature described. Its great sound has as much to do with tube output and the excellent PCM63 chip (imho one of the best chips ever; its 20-bit sounds superior to most of the 192 stuff now) as the use of interstage transformers.

Audio Note UK later moved on to non-oversampling (so-called 1x) but, while I like the sound and simplicity of non-oversampling, imho latter-day chips are inferior. Maybe I am biased; I have heard their very expensive ones many times in other systems, but none impressed me like my old DAC-2. I have also owned the admittedly much cheaper and non-oversampling DAC One 1x (6111 tube). While it was certainly cheerful and bettered the more conventional Zero of the time, it was not at all a match for the DAC-2.


Gotham 10070
2 runs of this cheap but reference-grade coaxial digital cables are used. This utterly transparent and musical S/PDIF cable has outperformed everything else in my system. While here, I shall tell you Gotham's XLR digital cable is equally distinguished (as are the entire line).


Analog interconnect cable from either digital system to the preamp is Gotham GAC-4, one of my references.

System Used
For those who don't know my Blog well, please go to the right hand column of the Blog; scroll down to see the equipment I use in both Hong Kong and NYC. This will give you an inclination on my preferences. For this round, I used:

Preamp: Kondo KSL-M7 (stock Sylvania 6X4; 2x Mullard ECC82)
Cable from Preamp to Amp: Gotham GAC-2
Amp: Kondo Ongaku (stock GE VT4C and 4x JJGZ34; triple-mica black-plate 6072; Tung Sol 5687)
Speaker Cables: Gotham 50150 (another marvelous Gotham)
Loudspeakers: Tannoy Canterbury HE

Notes on the Tannoy Canterbury For the past years, since I received them in very dark-sounding condition, I have run these in with increased treble energy and rollover. While these setting still work marvelously well with the WE setups, with the Kondo setup I have found restoring close-to-default settings reaped greater benefits, while extracting no cost from the WEs!
Although Kondo is not bright or harsh, its strong presence and unrivaled airy presentation demand partnering with the right loudspeakers. Those with overly strong or grainy treble just would not do, particularly with digital sources.

R pic of Ongaku front; click to enlarge.

Ongaku as Integrated Amp (Digital)
To facilitate comparison, I used the Direct In exclusively. Unlike some erroneous reports, this bypasses only the selector and renders the other inputs (except tape) useless. The source/tape selector, balance and volume all remain functional. Note that the balance function desirably operates over a usefully narrowed range. In my system, the volume knob ranges from 9 to 11 o'clock depending on the digital system used and material.

With such a "monumental" project, I opted to use one CD as my main test material, and the MANGER Test CD (tracks here) it was to be.
I am happy to report that both digital systems, though different in their presentations, yielded excellent sound.

Digital Systems 1 vs 2 In general, System 1 is more composed, always finely layered and cultured, never making an ugly sound; whereas system 2 has more rhythmic incisiveness and a more "vocally" declamatory nature, more "hifi" too if you will.

  • -Track 1 With System 1, the bells are more telling in their tolls, their tones more varied and differentiated.
  • -Track 2 The cinematic effects and timbers of the various personae are better differentiated by System 2.
  • -Tracks 3-7 These classical tracks are overall better rendered by System 1, no-less by more accurate portrait of strings timber, but in terms of rhythmic accuracy (tracks 6-7) System 2 has the upper hand (Sony is weakest in this area). System 2 also portrays the piano (track 3) with more body and realism.
  • -Tracks 8-10 and 12-13 These Jazz/Pop-influenced tracks undoubtedly has more emphatic and audible rhythmic variations with System 2.
With classical and complex material System 1 scores a little higher, whereas in smaller pop/jazz combos I'd give the edge to System 2. Overall, I'd narrowly give the edge to System 2 for its superior PRaT. Please note that System 2 has the much higher output, and I believe that is an advantage when using the Ongaku as integrated amp.

Ongaku + M7 (Digital)
Direct-in was used throughout. After hours of going back and forth, I have to conclude that, with digital playback, adding the M7 is not really that superior to direct-in:

  • With the M7 , the position of the volume knob of the Ongaku is somewhat arbitrary, up to the preference of the user as well as the nature of the music played. I am not certain what is the optimal, but I resist having it much over 12 o'clock, as I think past 1 o'clock or so the sound coarsens significantly.
  • Addition of The M7 immediately brings about a more panoramic soundstage that is greater in both width and depth.
  • With the M7, Digital System 1 gains perhaps a little speed in the leading edge and a firmer rhythm, though it shall never be the equal of System 2 in this regard. More, this comes at the cost of loss of a little subtlety in certain areas, like massed string timber. I also notice that the hall sound is reduced somewhat.
  • With the M7, Digital System 2 displays an even more upfront rhythmic signature, but the depth of attack and PRaT are not necessarily superior to direct-in. In other words, what benefits System 1 a little is less obviously useful here. Note also that the high output of System 2 can be attenuated with the level control of the M7, but it'd take time to arrive at the optimum; I used the 1 O'clock position.
  • Overall, with significant reservations, I'd say addition of the M7 brings about a somewhat more even quality, but digital direct-into the Ongaku can be a success (higher source input level desirable). So there is much room for tuning the sound.
Analog experience to come in Part IV. Suffice to say I also think the higher the cartridge's output the better...

2 comments:

  1. Hi. I own a Kondo Ongaku. I am wondering how you take the cover off the front to access the preamp tubes. Thx.
    Miguel
    miglto (at) gmail (dot) com

    ReplyDelete
  2. The cover is thin steel. After loosening the screws you can flex the side a little and it will go over the RCA sockets easily.

    ReplyDelete