In 'Explorations in Audio' I aim to share some practical insights on setting up and optimising an affordable HiFi system. Although one would think that, really, all has been said about HiFi, some surprisingly simple questions still remain, e.g.: 'Is digital superior to analogue?' 'Do cables matter?' 'Can digital cables pick up interference?' 'Should speakers be placed on spikes?' 'Has evolution in HiFi made older gear obsolete?' 'Where should I place my sub?' 'Which room correction works best?' - On the other hand: 'Are these really the right questions?' - We shall see.
While the entries in this blog are divided into the three distinct categories above, you will find a mixed listing of the most recent postings below. The most recent article is shown first. If this is not your first time visiting, the listing below is a good place to quickly check if anything is new.
Your input is more than welcome, as long as you follow the basic audiophile rule of ‘ear over mind’. This means that you do not comment based on what you think you know, but only on the basis of your own listening experience. Please feel free to suggest gear for testing as well as leave comments on the descriptions provided here.
HiFi audio systems usually find their place within a family's the living quarters. Some of them serve as entertainment centres in the living room; others form part of a home cinema setup. Audio systems may accompany an evening meal in the dining room or make working time more enjoyable in the study. Some are part of a bedroom suite or even complete a children’s room. Many households have only one large living room, which is used for everything from cooking to entertaining. In fact, very few households can afford the luxury—or have the sense or wisdom—to dedicate an entire room, or even an entire floor, to listening. And of those who do, very few homeowners have chosen or designed their homes solely for this purpose. In fact, HiFi is often the last thing on a homebuyer’s mind.
And yet, when Sabina and I toured the north of Germany in search of a home for our family, I stood for the longest time in that cathedral-like empty space under the roof of our (now) house, clapping my hands in disbelief at the unbroken silence that greeted me each time. "I want this room!" I thought. "We need this house for our family, for the language school, and certainly for the sake of my continued audio explorations. At the time, the 1980s glass wool insulation was dangling in large sheets from the ceiling beams, and the floor was a single layer of worn wooden planks with visible cracks between them.
eiaudio Moving to Marne in Summer 2023
Watch the video on YouTube
It was clear that this magnificent-sounding room could not be left in its original, unfinished state. The lack of insulation was causing significant temperature differences between day and night, and between summer and winter. And the wind was blowing through the shingles, bringing dust and insects into the house. My challenge was to tame this wild beast without breaking its delicate spirit. To do this, I had to find out what made the original room work so well for audio purposes, and ensure I maintained and built upon that. I started reading up on room acoustics and quickly realised that there were some established listening room standards that our space met quite well.
For one thing, the room had almost no parallel walls that would have accentuated first-, second-, and third-order resonances. Instead, the side walls were almost three metres high and sloped inwards at a 45° angle from a height of about one metre to the roof. The structure itself was supported by exposed wooden beams with many uneven tongue-and-groove boards between them. One of the few straight walls along the side was made of exposed brick. The central part of the roof had a slight dome shape, rising 30 cm in the middle. There was plenty of open space to arrange the loudspeakers according to their acoustic needs, and room for me to walk behind each HiFi rack when setting things up. This meant that I could access my setups from all sides if necessary and take care not to accidentally cross signal wires.
I first consulted an acoustics expert on the best flooring for the room but felt that his preferred combination of insulation and screed would be too heavy for the old building. So, instead of pouring concrete, I added a 30 mm layer of OSB, which we covered with carpet. It was important to me to maintain the structural integrity of our building. However, this meant that I had to find a way of damping the resonance that traveled straight down from the speakers into the floor. I gave this some thought and decided that 38 kg slabs of concrete—the kind used to lay a garden path—placed directly under each speaker would act in a similar way to screed. At the same time, the slabs allowed me to place the spikes of each loudspeaker directly onto the concrete for greater structural stability. As a result, the soundstage and clarity improved dramatically, and floor resonance was reduced by around 50%.
I understood that designing a room to handle acoustics effectively requires a balance of absorption, diffusion, and (sometimes) bass trapping to manage reflections, standing waves, and reverberation times. I therefore set about determining the most linear position for each loudspeaker and the corresponding listening positions using the room mode calculation sheets provided to me by Peter English. I then set up my UMIK-1 measuring microphone with REW software to analyse the output of my speakers and the reverberation times of the room over the frequency spectrum as perceived from the listening position. It is sometimes said that covering 30% of the wall surface with absorbing materials will give a relatively natural sound impression. In rooms where typical household remedies such as bookshelves cannot be placed, professional sound absorbers from specialist shops are an option.
In general, the absorbing materials should be placed where the sound waves from the speakers are reflected directly from the walls and ceiling towards the listening position. These locations can be identified by moving a mirror—held parallel to the wall—along these surfaces until the loudspeaker drivers are visible from the listening position. In the case of our studio, I used the open joist structure of the room to hang curtains in the corners and along both sides. Rather than leaving them open, I gathered them together with a rope to form large, soft columns. This already quietened the acoustics and made conversations in the room a much more pleasant experience.
Instead of the usual windows, our listening room has small openings covered with 30 x 30 cm Perspex panels. These were less of an acoustic problem, but we did have a 120 x 60 cm window to the adjacent control room, which caused some harsh reflections. I used blinds to effectively diffuse the sound reflections from the glass. However, when I sat down to listen to the result, I could still hear that I was in a large room. I suspected that the few straight walls were reflecting too much sound, causing echoes.
As we had just bought and renovated our entire building, I needed to come up with an inexpensive solution for suitable absorbers. I found this on Michael Wynne's YouTube channel "In the Mix", where he builds 1200 x 600 x 100 mm acoustic panels using wood, damping materials, and cloth. In my case, I used jute mats (density 45-50 kg/sqm) recycled from old bean and coffee bags to dampen the treble and midrange. Shredded jute is an inexpensive choice, but there are some drawbacks: the damping factor is acceptable, but certainly not on par with more professional solutions such as Basotect (compare: rock wool 50-200 kg/sqm). There was also an unpleasant smell of mouse droppings at first. As a child, I once visited my uncle at the Bavarian public radio station and, walking past an absorber wall, had the feeling of being physically sucked into a vacuum. My DIY absorbers certainly do not produce this kind of dramatic effect.
To add more sound diffusion to the room, I bought four large, bushy plants and placed them along each of the side walls. Due to the lack of direct sunlight, these plants had to be artificial. From an acoustic point of view, it makes no difference whether a plant is organically grown or made of plastic. Artificial plants have the added advantage that they do not require a heavy pot of soil and can therefore be more easily moved to different positions to address various acoustic issues. To further reduce room reflections at the listening position, I chose large armchairs with high, absorbent backrests. These serve to increase the amount of direct rather than reflected sound reaching the ears.
Since the presence of sound waves also excites the furniture in the room, especially if the floor is made of wood, I chose HiFi racks that are capable of absorbing vibrations. In these, each HiFi unit is positioned separately on a shelf, each of which rests on spikes. The hollow steel legs are then filled with stabilising quartz sand to absorb acoustic vibrations within the structure. HiFi units containing large transformers are separated from the sensitive drive units by a separate structure to ensure correct reading of the source material without external noise. The racks are then coupled to the floor by steel spike pads on 4 mm felt pads. Felt is a chaotic structure and prevents floor vibrations from affecting the drive units.
The combination of measures works very well in the room. Both the treble and midrange sound vibrant and natural without over-emphasising any frequency. Vocals sound hauntingly real with an ever-present goosebump potential. Instruments are free from the speakers and are reproduced in their correct dimensions and timbre. There is a superior order to the music. Bass is mostly neutral to dry, with lots of layers and nuances, unless it falls uncomfortably close to the exact resonance frequency of the floor. At the time of writing, this is the only flaw that I can detect in my listening setup. As with everything in life, it is a concession to our house renovation budget. It might be worth experimenting with bass traps in the future to see if they, too, might have a positive effect on performance.
< 31. Understanding Room Acoustics | 29. Room Mode Calculations >
Published: 06/10/2024
Author: Karsten Hein
Category: Explorations
Tag(s): Vintage Radios
Life could have gone differently for German HiFi, if the industry had fully embraced the idea of creating icons. I love the look and feel of those early days, when anything still seemed possible, and I am thankful to my grandfather for preserving this opportunity for me well beyond his lifetime. So, Rudi, this article is for you.
The Saba Wildbad 100 valve radio, produced from 1959 to 1960, is a classic German radio model with a wooden cabinet, a horizontal station table, and large rotary dials. It operates on the superheterodyne principle and covers frequency bands from long wave (LW) and medium wave (MW) to short wave (SW) and ultra-short wave (FM). The Saba models of this period were renowned for their robust engineering, superior audio quality and meticulous craftsmanship. The Wildbad 100 is no different. It is a respectable member of the collectible vintage Saba line and is still sought after for its sonic fidelity and aesthetic appeal.
My grandfather was a lathe operator and a turner who understood craftsmanship. He was adventurous and a jack-of-all-trades who could fix almost anything in the house. A trained policeman before the war, he also had a sober view of right and wrong and would not tolerate much nonsense from anyone. When he still worked shifts in the factory, he had to plan his free time wisely. In the winter it was mainly family time, which he loved to spend with his grandchildren when we came to visit. Besides working in the garden or building things out of wood and Lego together, I remember sitting with him at dusk, watching the headlights of passing cars create wondrous shapes on the ceiling of the living room, or listening to that very same Saba radio.
Having thrown out his old music chest, my grandfather rebuilt the old Dual turntable (which it had come with) to fit into his sideboard and used his new Wildbad to amplify the sound. He did not own many records—not in the way that collectors do today—but those that he did own he played with great pleasure. His collection contained music ranging from Classical to Folk and German Schlager, but he also had German comedy shows, such as Jürgen von Manger and Emil, which we kids only half understood but somehow greatly enjoyed. Part of the charm of listening sessions with grandpa was in the shared experience, of course. But there was also another kind of warmth that I would come to miss in later years—this warmth came from vinyl as a source and from the radio itself.
Although many performances from the 50s to 80s were poorly recorded, they all possessed a warmth, richness, and sparkle that made listening a pleasure. Looking like a guitar amplifier, the Saba had a resonant wooden body that was closed enough to provide a chamber but open enough not to sound boxy or confined. Unless external speakers and an additional stereo module were present, the output remained mono, coming from a 24cm bass driver, a 24cm midrange driver, and two 10cm tweeters, mostly hidden behind a relatively thick woven fabric. The tweeters were located behind plastic grilles on either side of the cabinet. Both the bass and treble output could be attenuated to adjust the sound to suit the room’s furnishings, proximity to corners, and personal listening preferences. Whatever the setting, the tube-driven Wildbad 100 sounded sonorous and inviting.
Although the Saba Wildbad 100 does not use the now famous Saba Green Cone drivers (which are typically full-range with ALNICO magnets and are found in other models such as the Freiburg series) it does deliver lush and musky vocals and an engaging tonality with sufficient bass slam when driven at moderate living room volumes. Much like the Green Cone drivers, the Wildbad’s set of four drivers will start to sound flat, strained, and distorted when driven too hard. The 4 Watts tube amp power are just enough to reproduce the tonality and the power of a full human voice. In my opinion, it is this discipline that makes the Saba radios of this period so attractive. The Wildbad 100 produces vocals that have tangible substance and an almost forbidden allure.
Pressing the first of the eight ivory buttons on the front, the EM84 tuning indicator tube flickers into action, without the unit making a sound. As the tube warms up to the radio station with an increasingly narrowing band, the sound of the radio begins with heavy distortion, until the amplifier tubes have gathered enough substance to drive the speakers. It then takes another five minutes for the Saba to sound complete and another fifteen minutes for it to sound at its best. Soon, the heat from the tubes can be felt as a warm glow radiating above the wooden cabinet. Consider for a moment the flimsy plastic boomboxes that followed the Saba Wildbad in the 1970s and 1980s. Hardly any of them were tuned to the harmonics of the human voice. As a result, they sounded cold and lifeless by comparison.
When my mother came to visit us at the North Sea a few weeks ago, I gave her a tour of our studio as it is now set up. She listened to our Martin Logan SL3 system with the superb Symphonic Line RG9 MK5 amplifier, Thorens TD 320 turntable, and Marantz CD-17 CD player, as well as to our Tannoy XT8f system with the legendary Symphonic Line RG9 MK3 amplifier. She enjoyed the music very much and became quite emotional at times. Later, as we were sewing the Molton curtains for the listening room, I turned on the Saba Wildbad radio. After some minutes she stopped sewing, and looked up: “Is that my father’s old radio?” She wanted to know. “It’s really very good. I had no idea it could sound like that.” And even though I have gathered lots of experience in setting up systems over the years and now know how to achieve tonal balance even in a complex setup, I was still amazed at the undeniable charm that the Saba Wildbad delivers straight off the bat. Sit with it in the dark for a while, and you will understand why its charm endures.
SABA is the acronym of Schwarzwälder Apparate-Bau-Anstalt, a privately owned company founded in 1923 in Villingen, Germany, by Hermann Schultze. Initially, it produced clocks and household appliances, but soon expanded into radio technology during the 1920s and 1930s. By the 1950s, the SABA brand had become well-known for its high-quality radios and television sets and gained a reputation for excellent sound quality, especially with models like the Freiburg series that featured the famous automatic station search and high-end "green cone" speakers.
In the 1960s, SABA began producing televisions and ventured into consumer electronics. However, increased competition from international companies during the 1970s affected its financial stability. The company was eventually acquired by the French Thomson-Brandt group in 1980, which marked the end of its independence. Despite this, the SABA brand persisted in various forms, especially in the TV market and under Thomson's ownership. SABA remains a nostalgic brand, which is admired for its craftsmanship in radio and audio technologies, particularly during its mid-20th-century heyday.
Published: 02/09/2024
Manufacturing date: 1996
Author: Karsten Hein
Category: Gear & Review
Tag(s): CD-Players
Pioneer’s PD-S 705 CD player came out in 1996 and was the top-of-the-range model of the new x05 series. Just above it, was the popular PD-S 904, which had been released in the previous year. Arriving shortly after its famous siblings, the PD-S 705 bridged the gap between them and was an attractive choice for consumers seeking the technology of the PD-S 904 at a more affordable price. The main drawback of the PD-S 705 was that, like the PD-S 604 and the other entry-level players, it lacked a coaxial digital output for proper connection to an external digital-to-analogue converter (DAC) or to the digital input of a preamplifier or amplifier. For most people of the time, however, this compromise in versatility would not have mattered much, because CD players were predominantly the only digital HiFi equipment in their home.
In April 2024 I wrote an article about the smaller PD-S 604, in which I highlighted the benefits of Pioneer's Stable Platter mechanism for critical and audiophile listening. The platter is an integral part of the player's drive unit and supports the disc in its full dimension from underneath, rather than just gripping it in the middle. This greatly reduces disc wobble and allows the source material to be read with great accuracy. Since the purpose of any hi-fi system is to amplify and attenuate this initial signal, its integrity is of paramount importance. The PD-S 705 uses the same technology, but with a more advanced drive unit (PEA1291 instead of PEA1179). The improvements over the PD-S 604 are noticeable in the smoother opening and closing of the mechanism, as well as an even smoother disc rotation, resulting in ultra-fast initialisation of the disc when the tray is closed.
My article then went on to discuss the benefits of Legato Link, which does not abruptly cut off the high frequency content of the CD, as most CD players do, but instead uses spline interpolation to create a softer and more natural or 'analogue' sounding top end. Whereas on the PD-S 604 this technology could sometimes emphasise treble content in an undesirable way - as if to create artefacts on some recordings - the effect was much less pronounced on the PD-S 705, if it was detectable at all. I am thinking of a 2007 Sony & BMG 'Kuschel Jazz' CD, on which some songs produced an ultra-wide and three-dimensional soundstage at the cost of occasional inaccuracies in the top end. Jazzy interpretations such as Joel Harrison & Norah Jones' 'I Walk the Line' may also sound a little sharp on the PD-S 705, but I could not detect any digital errors, anomalies, or artefacts.
Although it uses the same digital-to-analogue converter (PD2029A), the PD-S 705 offers a +2db improved signal-to-noise ratio of 110dB. To achieve this, the PD-S 705 sacrifices some of the features found on the PD-S 604. For example, there is no variable line output, which would allow the output signal to be attenuated towards the amplifier. There is no headphone socket on the front panel, and consequently no motorised volume control. Whereas the 1980s still saw elaborate control panels with lots of functions and buttons, the late 1990s brought about a return to the essentials, with a simpler design philosophy focusing only on sound. The latter is probably the reason why the PD-S 705 has an off switch for the LCD display. Personally, I was delighted to find this feature on board, as I know that most audio equipment only reaches its full sonic potential when the display is switched off. Stray currents from the display can all too easily introduce audible noise into the music signal.
On the PD-S 705, the audio output paths are switchable, allowing the user to activate and deactivate both the digital optical output and the analogue output separately, depending on the application, in order to reduce interference. The PD-S 705 reduces Total Harmonic Distortion from an already low 0.0028% to 0.0026%, which is significant when combined with the improved signal-to-noise ratio. Next to being 1.5cm taller, the PD-S 705 is also 300 grams heavier than the PD-S 604, which gives it a more stable base and compensates for the heavier disc tray. On the other hand, the cabinet is still made from the same cheap bent sheet metal found on most hi-fi equipment to this day.
With the PD-S 604, I learned that adding some anti-resonant foil to the inside of the cabinet helped to make the sound more assured. As I had bought my PD-S 705 in refurbished condition from a professional German up-cycler, complete with a limited one-year warranty, I did not dare break the paper seal. I like the concept of repairing and reselling older electronics, giving them a second life. With this in mind, I was delighted to find Positron-e GmbH of 85368 Moosburg in Germany, who sell their refurbished and approved products on eBay. For the time being, however, the warranty means that I will have to live with the standard metal cover for a while, and I cannot show you any photos of the inside of the player just yet. This, and the slightly higher price, were small concessions to having the security of a professional service centre at my disposal, just in case there were any technical problems down the line.
In general, Pioneer's PD-S players are well-built audio machines that will give you many years of trouble-free service. In my experience, they benefit from interconnects that are quick and revealing to keep the player from sounding dull. I use unshielded silver solid core cables in twisted pairs. These cables work very well and allow the Pioneer to integrate seamlessly with high-end amplifiers such as the Symphonic Line RG9 MK3 and the newer Symphonic Line RG9 MK5. Compared to similarly priced NAD players, the Pioneer's soundstage was a little less sharp, instruments were not quite as three-dimensional, but speed and rhythm were more engaging and seemed more lifelike. The PD-S 705 may not be the most spectacular player, but its faithful reproduction of musical events and pleasant, analogue-sounding top end make it a great all-rounder and perfectly suitable for audiophile listening sessions.
< Pioneer PD-S 604 | Symphonic Line RG9 MK3 >
Published: 08/08/2024
Manufacturing date: 1994
Author: Karsten Hein
Category: Gear & Review
Tag(s): Integrated Amplifiers
In summer 2024, Michael and Iris contacted me to say they were contemplating spending their holidays at the German North Sea. I very much welcomed the idea of seeing them again and could not wait to give Micheal a tour of our new studio. As our two guest rooms were already occupied at the time, my wife, Sabina, offered to help them find suitable accommodation near us. Michael, a fellow audiophile, who had previously lent me his wonderful Teufel M200 loudspeakers for exploration, informed me that he would be bringing along a smallish NAD 310 amplifier for testing this time. And, although I had always felt a little put off by NAD’s over-marketed audiophile-on-a-budget claim, I was happy to hear that Michael was once again offering to show me something new.
The last time I had heard an NAD system play music was during a visit to my former English lecturer Martin von Schilling’s apartment in Bayreuth. And, although some 25 years had gone by since then, I still remembered the sonic signature of the system to be very true to music. Of course, the material we listened to in those days was quite different from the calm Jazz and classical performances I tend to play today. In fact, I have fond memories of Martin racing my Audi 80 up the A3 towards Frankfurt with G&R "Mr. Brownstone" blasting on my custom car stereo. Therefore, I could not be certain how much of my positive impression of Martin von Schilling’s home stereo system had been due to my lack of experience at the time.
When Michael and Iris arrived at the North Sea, Sabina, our kids, and I spent the first evening with them at the levee in Friedrichskoog listening to live Rock & Pop music performed by some local cover band. The musicians had to brave heavy gusts of wind, and their PA system seemed to be compensating for this circumstance with excessive volume. Having refreshed our impression of live music, we spent the rest of the evening at a local restaurant, talking about music, our recent move from Frankfurt to the North Sea, and other family affairs. The need for additional space for our family, for our language school, but also for Explorations in Audio had been among the important factors in our decision to seek our fortune away from the banking metropolis.
In our new studio in Marne, I could, for the first time, show Michael three permanent HiFi setups in a designated listening space that was outside the living quarters of our family. Within this, each loudspeaker had been set up to allow for near-linear sound reproduction in relation to the specific characteristics of the room and the listening position. There were few parallel walls, and the furnishings had been chosen to reduce reverberation times. The available space behind each system allowed for easy installation and faultless wiring. It was the kind of playing field that most audiophiles can only dream of for their hobby, and it provided the basis for my assessments of the sound quality of HiFi components.
At the time of Michael’s visit, my reference system consisted of a Thorens TD320 turntable (with AT VM95 ML cartridge and Audiophonics linear power supply), a Marantz CD-17 CD player (complete with Ken Ishiwata-styled output stage), a much heralded Symphonic Line RG9 MK3 integrated amplifier, and Martin Logan SL-3 electrostatic loudspeakers. The cables were Symphonic Line Harmonie HD interconnects (from CD) and Belden 9497 speaker cables set up in Y-bi-wiring from a single point of contact on the amp to the separate high and low terminals of the loudspeakers. A Symphonic Line power cord and a dedicated power installation—a straight line leading to the central fuse box of our house—assured the availability of clean electricity in abundance.
Although the NAD 310 could (at least in theory) have driven my Martin Logan speakers, given its extensive high feedback handling abilities, both the electrostatic panels and the dynamic woofers of the Logan’s hybrid design demanded for a higher wattage power amplifier and would have been an unfair match for the NAD’s modest 20 watts RMS per channel. My Tannoy XT8f loudspeakers, however, which were part of the adjacent system, were relatively easy to drive at 8 Ohms and a high sensitivity of 91 decibel. And it was this system that we connected the NAD 310 to.
The frontend consisted of a Pioneer PD-S705 CD player which once was famous for its platter drive mechanism and inverted disc placement. As the NAD 310 does not feature an integrated phono stage, we simply accepted the fact and did not make any attempts to connect a turntable via an external phono stage. The cables were Stager Silver Solid Core interconnects from CD and Symphonic Line Harmonie HD cables in single wiring to the speakers. We used 4mm-thick solid core copper wire jumpers to connect the Tannoy’s high and low frequency drivers. The speakers themselves were positioned on their bare spikes, which firmly held the Tannoys in place on top of immovable 38kg stone slabs. This infrastructure was surely not the typical environment for the affordable NAD 310 to perform in and therefore promised to be interesting.
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Michael and I began our listening session with a live performance of the German Tom Waits cover band “Bad As We” that was recorded straight onto an analogue reel-to-reel tape machine by the former Bavarian public radio sound engineer Andreas Sandreuther and the Nürnberg analog-treff founder, Heinz-Peter Völkel. Live||Tape is the name of their new (strictly analogue) label, and even when re-mastered for CD, the dynamic range and bare bones realism of the original recording are impressive. Michael and I had previously listened to the CD performed on large pre and amplifier combos and were surprised to find that, with the NAD 310, much of the original drive, tonality, and dimension remained the unchanged. This realization was especially perplexing considering the NAD’s modest size, weight, and tiny circuit boards.
There is something about hearing a performance first hand that is difficult to transport in a written report. And I confess that very little we could have read about the NAD would have prepared us for the event. With our eyes closed and at normal listening volumes, we would have easily mistaken the sound of the NAD 310 for that of a pre and amplifier combo, and a very good one at that. In direct comparison to my Restek V1 and Echle LF-3519 setup, the NAD was less forceful, occasionally lacking some of the bite of the piano notes. However, on many recordings this proved to be a good thing rather than a liability. Despite losing some of the discerning edges of a music event, the NAD 310 managed to maintain excellent tonality and homogeneity and propagated a decidedly non-fatiguing and highly musical sound.
Vocals were rendered with natural detail and recognisable timbre, and the sound stage showed similar width and depths as I was used to from my separate components. In direct comparison to the Restek V1 and Echle LF-3519 setup, however, the NAD 310 provided less space around each instrument, making each sonic event seem closer to the next in terms of time and space. This became especially clear when we listened to Helge Lien’s album “No. 10”, which superbly plays with the listener’s sense of space. Having listened to Singer-Songwriter and Jazz music with me for a while, Michael asked me, if I also had some electronic music at hand.
I first thought of some iteration of a Boris Blank album, but then I remembered that I had just stumbled upon a 1993 Culture Beat album sitting on one of the free take-away shelves along the streets in Husum. For both of us, it had been years since we last listened to a Torsten Fenslau production, and we had to smile at the improbability of this idea. Michael remembered that, on the album “serenity”, track number three “got to get it” with vocals by Tania Evans used to be quite popular. We cranked up the volume and were transported back to the dry German Disco beats of the 90s. The NAD 310 managed to handle the increase in volume very well and, to our surprise, did not seem at all strained or compressed. The Tannoy’s high sensitivity and 6dB bass accentuation probably played a part in this solid performance.
Being greatly pleased with our listening test of the NAD 310, Michael and I decided to end our session by taking the Culture Beat CD over to my Martin Logan reference system (with RG9 MK3 amplifier), thinking that we would pretty much hear more of the same music. To my relief, however, this was not the case. The Martin Logans made each sample come alive with such width, depth and sparkle that the previous performance seemed somewhat pale and lifeless in comparison. There was so much detail and dimension that even the crude Culture Beat disco album started to make sense to me now. I think Michael and I were both a little surprised by this transformation, because there really had been nothing “wrong” with the system we had listened to before. On the contrary, it had delivered an excellent performance that left very little to want for at the time.
The NAD 310 is a budget amplifier that punches well above its weight and employs some clever design choices to perform this trick. Rachel Cramond wrote an extensive review about this phenomenon for Gramophone magazine in 2012. (They let you read it a few times before erecting a pay wall). Next to the cost saving reduction of electronic parts by approximately 50%, the NAD 310 features a pure class A driver stage and a carefully matched combination of MosFET and bipolar transistors. One difference to conventional A/B amplifiers can be seen in the two large capacitors found to the right of the heat sink (see photo) on the amplifier board in addition to the power supply caps that are located next to the toroidal transformer.
The secondary capacitors assure that there is always plenty of dynamic headroom, even when the amplifier is driven near maximum volume. There are limitations in terms of slew rate and signal damping that cannot be denied on a 20 watts amplifier. It is therefore best matched with responsive electronics at the front and sensitive speakers at the back. My choice of unshielded silver cables and the Tannoy speakers worked very well in this respect.
Although the NAD 310 had been in Michael’s possession for some years already, he had never heard it perform in such a dedicated listening environment and meticulous setup and therefore was quite surprised by how much of the performance depended on the periphery. And I had never heard a piece of equipment in this affordable price bracket that could so well hold its own in such an environment. I am certainly going to look at NAD’s rather flimsy looking amplifier designs with more respect now. I can promise you this: under normal household conditions, any restrictions in musical fidelity heard in conjunction with the NAD 310 are most likely caused by how it is matched with the periphery and not by the amplifier itself.
Power Amplifier
Preamplifier
General
Published: 15/07/2024
Manufacturing date: 2024
Author: Karsten Hein
Category: Gear & Review
Tag(s): Speaker Cables
“Don’t know how you’d find me, I don’t look much like the photos. Whatever man you’d come to look for, I’m not him.” sings Sean Keel, smack centre and wonderfully surrounded by the sound of acoustic and slide guitar lingering miraculously suspended in our studio. I can tell that my old Denon DCD-1420 is at times having difficulty keeping its worn-out laser optics focused on the track, thus giving Sean’s already cracking voice an even more endangered and fading impression. The amplifier of the evening is my thirty-year-old Uher UMA-1000, which—in combination with Luigi’s Mark Levinson HF-10c speaker cables—lends sonority and substance to Gabriel Rhodes’ sparse piano notes.
Keel's voice sounds musty with age and wisdom: “You sang blessed assurance. And then it was my favourite song.” The firmness and tonal richness with which our Tannoy XT8f speakers present each key stroke confirms the reality of assurance, despite the risk of losing it all right in the next second. It is a good evening for listening to slow music, with each note as distinct as it can be. Perhaps it is the start of the holiday season that supports this vast amount of clean energy from the grid, perhaps it is my cheerful mood, following the return of summer after a seemingly endless winter season that dragged on well into July this year.
Having been out of service for a long time, the large and heavy Mark Levinson copper cables proved difficult to resuscitate. Luigi had handed them to me without proper terminations and, in passing, told me to get some plugs that would fit the 6mm cable diameter. It was typical of Luigi’s suggestions to require at least some form of effort from my side. And I was usually only too eager to simply tag along. I liked the lockable gun-shaped WBT-0610 CU banana plugs that I had first seen on the HMS Gran Finale cables, but I was reluctant to spend that much money on a pair of cables that weren’t my own. I therefore ended up with an affordable replica of the WBTs, hoping that I would (from an audiophile’s perspective) get away with it.
It was obvious that the cable ends had seen some oxidation in their time, despite the fact that their bundle of individual strands—each no thicker than a human hair—was soldered to a single chunk at the point where the original terminations had been. I firmly sunk the hexagon screws in the solder, fully aware that these cables would take still considerable time to break in. On a side note, I have sometimes found that break-in times do not require the equipment to be running all the time, for as long as the components remain connected. The very fact that copper, led, brass, and gold are brought in direct contact with each other already leads to a slow homogenisation of electrical properties at the transition points, minimising the resistance between them. This is not a scientific statement, just something I have acoustically observed when confectioning and listening to new cables over the first couple of weeks.
I call the Tannoy XT8f setup my “new” system, not so much because of the age of its components, but because of the Tannoy’s relatively “modern” sound. Loudspeakers of our time tend to be tuned to measure well in the labs, whereas the engineers of the past did not have lots of fancy measuring equipment at their disposal. They almost exclusively had their ears to rely on. And—believe it or not—human ears are not a bad yardstick when it comes to making decisions on the merits of sound. This also explains why some classical instruments still sound superior to modern gear, despite the fact that technology has involved. The Mark Levinson HF-10c in combination with my old Uher amp make my Tannoys sound “musical” above all else, and this despite their tendency to sound modernly analytical.
Music becomes impressive with dynamics, but it only comes alive with tonality. The HF-10c support darker and more full-bodied tones. Pair them with a weak amplifier, and you will witness the life being sucked from the amp. The 150 watts per channel Uher, however, has no difficulties driving them. I can hear the amp, too, slowly coming out of its many years of hibernation. “World’s got a brand new baby, I lie awake listen to her bawl. Must feel a lot like flying.” Tonight, I understand what Sean means by it. I enjoy evenings like this, when the air smells clean after the rain, and the setting sun forms square orange patches on the otherwise anthracite carpet and the wooden beams in our studio.
I am reminded of the Madrigal Flat Copper cables that Luigi handed me for audition back in January 2022. Mark Levinson related products always seem to have an interesting twist to them. Something that makes them a keeper, even if the times have moved on. The musicality of the HF-10c is quite striking, even though speed, detail, and bass control are perhaps not their greatest forte. After all, these are not exactly shortcomings, when it comes to mitigating the deafening effects of high-power amplifiers. And Mark Levinson certainly has some of those in the house. High damping factors, lots of clean burst power right up into the treble, beryllium or titanium dome tweeters on loudspeakers, all these lab approved technical overkills will find a soothing counterbalance with these cables.
Going through my usual repertoire of Folk, Jazz and Vocal Jazz, and Rock, the HF-10c maintain a soft and silky treble that is assuringly non-aggressive even when listening at higher volumes, a charming midrange that I can quickly warm up to, voluptuous true to life vocals that are displayed on a wide centre image, warm tonality and (especially in Jazz performances) a realistic amount musical detail. The sound is tube-like, rich and wholesome with stern piano notes. The cables offer a medium length of sonic decay, not as shortly cut as MIT’s Terminator 5 cables and not as long-lasting as Symphonic Line’s Harmonie HD.
In terms of potency, the Mark Levinson remind me of the Symphonic Line cables, although they are quite different: The Symphonic Line play louder and are more agile. When piano notes become piercing, this is apparent on the Symphonic Line cables first, because the HF-10c are far more forgiving. Bass control is firm and punchy on the Harmonie HD and perhaps overly punchy in some frequencies on the MIT cables. To achieve the same result of bass contour and punch with the HF-10c, one would need an amplifier with massive power and a high damping factor. And I do believe it was this powerhouse of an amplifier that the Mark Levinson engineers had in mind when they commissioned the HF-10c with a cable specialist in Switzerland following their legendary “never-mind-the-cost” approach.
If you happen to live within reach of 25709 Marne in northern Germany and own vintage Hi-Fi Stereo classics waiting to be explored and written about, I would be honoured to hear from you!
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Audiophile greetings,
Karsten