Explorations in Audio

Karsten Hein

Are you ready to Explore?

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.

What's new in eiaudio?

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.

  • Symphonic Line Harmonie HD

    Symphonic Line Harmonie HD

    Published: 09/06/2024

    Manufacturing date: 1994

    Author: Karsten Hein

    Category: Gear & Review

    Tag(s): Speaker Cables

    [Test in Progress. Full review coming shortly.]

    Jörg Hegemann
  • MIT Terminator 5

    MIT Terminator 5

    Published: 06/06/2024

    Manufacturing date: 1995

    Author: Karsten Hein

    Category: Gear & Review

    Tag(s): Speaker Cables

    The innovative MIT cable company is based in Reno, Nevada. And, although their acronym is the same, there is no relation with the world-renowned Massachusetts Institute of Technology. Much rather, the cable company’s letters stand for “Music Interface Technology”. Bruce Brisson, the head and master mind of MIT, is most famous for his research on how to eliminate the typical comb filter effects on signal cables. The Terminator 5 speaker cables were launched in the mid 1990s and already employ MIT’s patented multi-pole network technology.

    The Terminator 5 offer a single-wire design that measures an impressive 12 mm in diameter. The specimens given to me for testing measured 3,60 m in length, with the network box (14 cm in length) starting at 2,60 m distance from the amplifier or 2,46 m from the loud speakers. With the signal direction indicated by small arrows running along the sides of the cables, the network box must be placed closer to the speakers than the amplifier. In most setups, the trademark network box with logo will therefore be visible somewhere in the open space between the loudspeakers and the HiFi system that drives them.

    I first listened to the Terminator 5 cables perform at Matthias’ house when auditioning his Duevel Bella Luna loudspeakers. He was driving his omnidirectional horn speakers with a Devialet Expert power amplifier, and one of the first things I noticed was a slight midrange compression that I primarily attributed to the horn drivers of the loudspeakers. It was only upon closer inspection of the system that I saw a loop having formed on one of the MIT wires, most likely due to a careless moment during their installation. We got rid of the loop, and the horn compression effect bothered me much less, although some minor traces of it still remained.

    When Mattias upgraded his HiFi system from the Duevel Bella Lunas to their flagship Jupiter speakers, he also swapped his MIT Terminator 5 cables against more capable contenders. And, seeing that I was interested in the MITs, Mattias suggested that I take them to our new studio in Marne for a more thorough examination. I was thrilled to be given this opportunity and quickly agreed. After all, one year had passed since I first listened to the Bella Lunas, and I had since then come a long way in my own explorations. The new studio, especially, had given me the chance to explore the subject of sound more deeply than ever before.

    In the cable test that followed, I compared and contrasted the MIT Terminator 5 with three other popular vintage brands: Mark Levinson’s HF-10 C, a Swiss-made 10 AWG multi-strand ultra-pure copper wire; Symphonic Line’s Harmonie HD; and Sommer Cable’s entry-level Elephant cables. All of them had previously been re-confectioned with gold-plated banana plugs to increase usability over the original spades. There is not much I can say about the quality of the (mostly solid prong) connectors other than to state that they were all free from visible wear and corrosion. The Sommer Cables were the only ones using hollow banana plugs, which happen to be my personal favourite when confectioning wires.

    My listening setup consisted of a Restek V1 preamplifier with external “Kassel” power supply. The preamp had been upgraded with new caps and ops by Restek a few years earlier and had generally performed well since. The amplifier was Symphonic Line’s RG11 MK5 S. I used Symphonic Line’s “Das Schnelle” interconnect between my Cambridge DAC Magic and the preamp as well as an older Symphonic Line Harmony HD cable between the preamp and the power amplifier. The Sansui SR-525 direct drive turntable was connected via my own silver solid-core interconnects, which generally served well in this position.

    Connecting the Terminator 5 to my Tannoy XT8f floor-standing loudspeakers, I noticed how positively solid the single-wire design makes these cables feel. The materials are highly durable and still looked great after more than 30 years of service. As non of the wires in my test were made for bi-wiring applications, I had re-fitted the Tannoy’s dual binding posts with bridges made of 4mm solid-core copper wires cut and stripped from home installation cables. I connected the speaker wires in the typical fashion for single-wiring, directly addressing Tannoy’s dual-concentric drivers and then running the bridge down to the bass units from there.

    From my listening position, I enjoyed the sophisticated look of the MIT cables. The network box was placed on the carpet floor right next to the speakers with the Terminator branding being clearly visible. This was my most “modern”-sounding setup, as the Tannoys could offer lots of musical detail, and the Restek V1 preamplifier, too, contributed to an open and transparent sound. The RG11 MK5 S is a highly musical and exact amplifier offering superb dynamics as well as tonality. From my first impression, it did not sound quite as tonally dark and rich as the Symphonic Line RG9 integrated amp, which would again appeal to a more modern Zeitgeist. The Symphonic Line interconnects could be quite unforgiving of flaws, and it was good fortune that neither of the components had the tendency to sound harsh.

    I played music from two CDs: The German “Stereo” magazine’s song compilation “Die Hörtest CD Volume IX” lent to me by Arndt Voss and Diana Krall’s “Only trust your heart”. Stereo magazine’s CD offered the greater recording quality and more variety in the songs, however, I knew Diana Krall’s CD better, which allowed me to comment more accurately on tonality. On my Sansui turntable, I played Jazz albums by Helge Lien in order to have an alternative yardstick to the CD player and DAC. The MIT cables were the first specimens I auditioned in my test. I turned on the RG11 MK5 S and felt the reassuringly solid clang of the new Super-transformer being magnetised, long before the relays clicked in to engage the loudspeakers. I believe, there is no sensation quite like the buzz of powering up this amp.

    Eduard Strauss’ “Bahn frei Polka” is a classical music piece performed by a large orchestra, and I was quickly reminded how important correct tonality is in maintaining order in multi-layered music. The MIT Terminator 5 supported the clean presentation by keeping a dark background. This assured an ordered and sophisticated sound. On Scotty Wright’s “Sound of Silence” I noticed the MIT’s midrange-focus and clarity that was topped off by a soft and silky treble. The singer did appear a little smaller than was otherwise usual on this system, and there was also that sensation of squeakiness again, which I had previously encountered when visiting Matthias. This was especially noticeable on female vocals, as I experienced with Tokunbo’s song “New June” but also when listening to Diana Krall's performances. I examined my system to see if either of the cables had accidentally become entangled behind the rack, but I could find no such fault.

    In addition to the slight compression of the midrange, I could detect a bass hump in the area of 100 - 150 Hz. While this had worked well with Matthias’ Jupiter speakers, it did lead to occasional resonances in my listening setup. California Project’s song “Wouldn’t it be nice” starts with an ultra-loud drum beat. In combination with the Terminator 5 cables, I must confess that I almost fell of my chair. Dynamics in the kick-bass frequency range were truly beyond the ordinary, and none of the other cables packed such punch in this category. The MIT offered a super-wide stage impression and superb instrument separation on an otherwise black stage. This characteristic was supported their ultra-quick sonic decay. I also noticed a preference towards warm and wooden tones. Tonality therefore was a bit more confined and not quite on par with some of the best (but also more expensive) cables I have heard.

    Despite being more than 30 years old, MIT’s Terminator 5 provided an enjoyable and engaging listening experience with a sophisticated presentation. Their slight lack of tonal accuracy might easily be forgiven, considering the many advantages the cables offer. Among these were: Superb dynamics, a generous stage width, the physical separation of instruments from left to right (not so much tonally), a leaning towards pleasantly warm wooden tones. They were also capable of surprisingly low bass, whenever this was provided by the source material. The cable fits music genres that is fast and punchy, such as electronic music, Pop, Rock, etc. Due to its tweaked tonality, it would probably not be the first choice for listeners with a preference for Classical music, Vocal Jazz, or Singer Songwriter, unless it is able to balance out existing system flaws leading in the opposite direction.


    • Type: Single-wire loudspeaker cable
    • Directional: Yes. Indicated by arrow.
    • Length tested: 3.60 m (per channel)
    • Termination tested: Nakamichi banana plugs
    • Cable diameter: 12 mm
    • Compensation: via network box

    crossXculture Business Language Training
  • High End Society

    High End Society

    Published: 01/06/2024

    Author: Karsten Hein

    Category: Explorations

    Tag(s): High End Society Germany

    HiFi (High Fidelity) devices of superior musical quality have been referred to as "High End" since the early 1980s. And with Rolf Gemein's Symphonic Line RG9-MK3 tonally capable integrated amplifier, eiaudio has also found its entry to the subject of High End. Rolf Gemein was among those who helped to establish the term and was also among the founders of the High End Society, an association with a long history and tradition.

    What is known as the High End Society e.V. today was founded on 18 December 1981 as an interest and advocacy group under the name "High End Interessengemeinschaft für hochwertige Musikwiedergabe e.V." in a small hotel in Alzenau, Bavaria. The initiator of this first meeting was Dipl.-Ing. Klaus Renner from Munich, who was at the time undertaking preparations for his new audio magazine "Das Ohr". In his eyes, conscious listening (an audiophile pastime activity for the experience of the joy of sound) deserved a much higher status than it was given by the predominantly mixed audio/video consumer trade fairs. A separate trade fair especially made for the High End audio sector was to rectify this situation. The twelve founding members of this interest group were:

    High End Inaugural Meeting

    (Frankfurt am Main, 10 December 1982)

    1. Klaus Renner, "Das Ohr" magazine (Munich)
    2. Christina Puschmann (now Ishizuka ), P.I.A. HiFi-Vertriebs GmbH (Mörfelden-Walldorf)
    3. Dieter Burmester, Burmester Audiosysteme (Berlin)
    4. Kurt Wolfram Hecker, Kurt Hecker GmbH (Frankfurt am Main)
    5. Rolf Gemein, Vernissage Laboratorium (Duisburg)
    6. Branco Glisovic, Pirol Audio Systeme (Böblingen)
    7. Jochen Rebmann, Taurus/Clear Audio (Nürtingen)
    8. Hermann Hoffmann, Audio Int'l GmbH (Frankfurt am Main)
    9. Werner Schmitt, AVP GmbH (Hanau)
    10. Helmut Püllmanns, Püllmanns GmbH (Cologne)
    11. Dusan Klimo, D. Klimo GmbH (Reutlingen)
    12. Thomas Deyerling, Audio Arts (Frankfurt am Main)

    1982 - The first High End Audio Fair is held at the Intercontinental Hotel in Düsseldorf. The trade fair opens its doors from 19 - 26 August and already manages to attract a large number of visitors.

    1983 - The High End Audio Fair relocates to the more spacious Kempinski Grand Hotel Gravenbruch in Neu Isenburg, near Frankfurt am Main. This hotel offers more space than the Intercontinental, suitable for the growing number of presenters and visitors.

    1990 - The name is changed from the rather complex High End Interessengemeinschaft für hochwertige Musikwiedergabe e.V. to the more internationally recognisable "High End Society e.V."

    1995 - The "High End Society GmbH" is founded to build the much needed framework for the growing operative side of the business.

    2003 - Founding of the new "High End Society Marketing GmbH" for the professional organisation and coordination of the trade fair, attributable to the persistent rise in membership and visitor numbers.

    2004 - Relocation of the High End audio fair to the more versatile MOC exhibition centre in Munich's Freimann district. This move is again a result of the increased need for space. However, the new venue cannot quite hold a candle to the former Neu Isenburg Kempinski Hotel, neither in terms of its central geographical location nor its more general ambience.

    2014 - Renaming of High End Society Marketing GmbH as "High End Society Service GmbH" to better reflect the broader scope of services rendered.

    2019 - Sees a further expansion of the range of services: For instance, the newly formed “SoundsClever" label aims to make High End listening pleasures affordable to audiophile beginners, despite a general trend towards rising prices in the industry. To make this possible, ready-to-play HiFi packages are offered at attractive set-prices of around EUR 5,000 and this with some genuine High End qualities.

    2022 - Start of the IPS (International Parts und Supply) section, a fair-in-the-fair venue for Original Equipment Manufacturers in the audio industry. In the meantime, the Munich High End has advanced into the world's most significant trade fair of its kind, with around 20,000 visitors and 800 brands from 450 exhibitors representing 40 different nations.

    Source: Uwe Mehlhaff, "Hörerlebnis" - Das Magazin für High Fidelity, 2022

    80s night
  • Stager Silver Solids

    Stager Silver Solids

    Published: 27/05/2024

    Manufacturing date: 2000

    Author: Karsten Hein

    Category: Gear & Review

    Tag(s): Analog Interconnects

    Marc Stager has a passion for audio. His business, Stager Sound Systems, is located in New York City, and provides high quality sound systems for concerts and special events. Marc’s focus on delivering undistorted and natural sound to both intimate and large-scale music venues also led him to explore the subject of wiring between the components and culminated in the development of his own line of audio cables. It was in this latter context that Marc reached out to me to inquire if I would be interested in writing a review on a set of his cables.

    Marc’s query reached me at a time when we had just completed the move of our businesses and family from the bustling city of Frankfurt to the sleepy North Sea town of Marne. The new location provided eiaudio with its own 70 square meter listening space, along with an additional control room for recording purposes. And, for the first time in the history of this blog, I was able to set up systems completely outside the family’s living quarters, positioning my loudspeakers to fully factor in room resonances, treating the floors and walls for reduced reverb times, and assuring that clean electricity would reach each of my three HiFi systems (that I used for equipment testing) straight from the central fuse box of our stand-alone house. There was sufficient crawl space behind each rack to allow for carefully thought-out wiring schemes and to assure that there was no accidental cross-induction between the wires that would deteriorate soundstage or transients.

    At that stage, I had already written over 180 articles and reviews on HiFi gear and recently established a connection with Symphonic Line, the German manufacturer of High End audio equipment. Testing their vintage components had rather unexpectedly broadened my horizon in terms of tonal accuracy in music reproduction. Although this was a subject that I had previously been aware of, I had never heard this aspect so flawlessly executed as to appreciate its value for the impression of musical integrity. To put it in a nutshell, I had established a professional testing environment and was now familiar with a whole new dimension of audio pleasures. Feeling set for my next stage of explorations, I eagerly wrote back to Marc saying that I would indeed be honoured to give his cables a listen and write a review on them.

    The Stager Silver Solids arrived rolled up in an unpretentious cardboard envelope just a few days later. I inspected the cables and saw that they had survived the trip in excellent condition. My specimens were terminated with Marc’s standard Canare F10 Cinch/RCA connectors that have a machined brass centre, a Teflon insulator, and 24K gold-plated contacts. According to their specifications, the Canare plugs’ coil spring strain reliefs are able to take rather hefty wires of up to 6.0 mm in diameter, a fact that somehow made them look out of proportion when used in combination with the approximate 2 mm diameter of the two twisted Stager wire strands. The Canare F10 have a solid centre prong (rather than a hollow or split one) and use a non-adjustable ring ground rather than providing a single point of contact, which is the predominant fashion in High End applications these days.

    Stager’s cable conductor is manufactured from a twisted pair of 99.9% pure soft-temper 24 AWG solid-core silver wires. According to Marc, each strand is hand-polished to create a grainless surface and is then placed inside a translucent Teflon (PTFE) insulator. The cable ends are colour-coded red and black using Polyolefin heat shrink tubing. Without further mesh shielding in place, the cables are non-directional and can be connected either way. From their specifications, I gather that their ‘unshielded’ symmetrical design assures a low capacitance of 11 pF/ft. However, I do believe this is true before the massive Canare plugs are in place. Protection from outside interference is provided by the cable’s twisted pair layout that is wound at approximately 1 cm per half-turn.

    The idea of twisting cables for improved interference protection is not new. The first time I heard the term was in the context of telephone and LAN connections, where twisted pairs are found in combination with wire mesh and/or aluminum shielding to assure superior signal integrity. In cinch/RCA audio connections, twisted pair designs also have a long tradition. I once had a 22 AWG Western Electric cable for testing that used a twisted pair of solid-core copper with silk dialectic to generate exceptionally sweet-sounding vocals, above all else. My favourite all-round speaker cable (in conjunction with vintage loudspeakers) is the Belden 9497 that twists two wires of tinned copper multi-strands at a winding ratio of about 5mm length per half-turn. A comparable shielding effect is reached by means of tri-braided field geometry, as it is propagated by Kimber Kable, amongst others. I had the Kimber Timbre in my collection for a while and remember that this, too, served its purpose quite well.

    Silver solid core wires are a completely different beast, of course. When it comes to audio connections, a solid core design offers great musical homogeneity, whereas silver provides superior connectivity. If the music signal ‘moves’ through copper, it ‘crashes’ through silver. When changing from copper to silver, I get the impression that the brakes come off, the music can finally breathe, dynamics can unfold, and that I am listening right through the recording to where the music hits the studio floor. I first discovered this phenomenon with the silver cables that Holger Becker made for me. I remember that we had lots of fun with our new discoveries and with each new cable became bolder, until shielding and plugs finally served to meet the benefits silver had to offer. Or so we thought.

    Curious about how Marc Stager’s Silver Solids would perform in this context, I first connected his cables between my Cambridge DAC Magic and Symphonic Line RG2-MK3 preamplifier. I gave the setup about one week to break in and then first wrote my review on the RG2 preamp. The Silver Solids remained in the system for the duration of my review and positively contributed to some of my observations on the sound of the system. My own (first generation) silver solid core cable, running from the preamplifier to the Dynavox VR70E-II tube power amplifier, needed to be replaced, because Symphonic Line’s own Harmony HD cable managed to produce superior dynamics in this position, especially when playing in conjunction with Symphonic Line’s speaker cables. — Well, such is life.

    When I finally focused on Marc’s cable for review, it had already played at least 80 hours of music. To fully mature, silver wires tend to take approximately 200 hours. It is therefore quite possible that some aspects remained hidden from me during my review. I started my session re-playing some local German music highlights, such as Bad As We, the Senior Jazz Trio, Anna Boulic, the Sunday Morning Orchestra, and Alexander Möckl from CD, all of which Heinz-Peter Völkel and Andreas Sandreuter had recorded in their Live||Tape sessions. Their idea was to record all the songs live using a professional reel-to-reel studio recorder, in order to show how well analogue recordings really worked. It was a fun project, and the only downside was that they had to transfer their masters to CD for me, because I did not have a tape machine of my own, yet. The recordings had an ‘anything-can-happen’ small stage flair to them, and I enjoyed listening to them a lot.

    The Stager Silver Solids contributed to a tonally pleasant and engaging sound. They allowed low bass to thunder right through without any unnatural restraint. Somewhat unusual in the context of silver end-to-end cables was the fact that the treble remained soft and silky, instead of turning bright and crisp. I attributed this pleasant softening of the treble to the material transition from silver to gold-plated brass plugs. Despite this, there was sufficient detail retrieval to provide for a joyful presentation. I was happy to note that Symphonic Line’s trademark tonality remained intact. This made it possible to better distinguish between a multitude of singers and instruments when the session became crowded. After all, tonality also conveys feeling and thereby assures that we remain attentive to the music from an emotional perspective.

    As with most twisted pair and braided cables, I found the stage to be huge and at times slightly out of proportion, with individual tonal events freeing themselves all to easily from the loudspeakers in an uncalled-for fashion. Under normal circumstances, I might not have noticed this ‘carelessness’ so much, if it had not been for Symphonic Line’s reputation for maintaining strict order and proportion in the music. To explore this effect further, I connected the Stager cable on my second system between the Symphonic Line RG9 integrated amplifier and RG11 power amp. In this scenario, the RG11 was driving the electrostatic panels of our Martin Logan SL3 loudspeakers, whereas the RG9 was supporting the bi-amping setup in driving the dynamic woofers. The Silver Solids did a tremendous job in terms of dynamics, tonal accuracy, and detail retrieval. However, the sensation of unbridled proportions remained.

    Reading Adam LaBarge’s review of the Stager Silver Solids on 'The Audio Beatnik', I saw that Adam had also used them to positive effect between his turntable and preamplifier. As I had never been able to run twisted or braided cables in this rather delicate position myself, I decided to give this another chance and connected the Stager cables between my Dual CS-505-3 and RGR Model 4 preamplifier. Perhaps not surprisingly, the result was an obnoxious 50 Hz hum paired with some high frequency hissing. When I replaced the Silver Solids with Fast Audio’s Black Science or Symphonic Line’s “Das Schnelle”, any background noise disappeared at an instance. To assure that the Stager cables did not have a defect, I whipped out an older braided Audiocrast silver-clad copper interconnect and found that this produced even louder noise than Marc’s cable had done. Good to know that Marc also provides shielded phono cables that will perform much better in this position, nevertheless, our short phono experiment serves to demonstrate that differences in cable shielding do exist and matter.

    Having arrived at my third HiFi system, I alternated between Audiocrast’s silver-clad OCC copper cable, Stager’s Silver Solids, and Symphonic Line’s “Das Schnelle”. The loudspeakers were my Epicure EPI 500, driven by a rare RG9-based power amplifier with RGR Model-4 preamp. The CD player was the rather enjoyable Pioneer PS-S604 with platter drive disc mechanism. I listened to the Jazz performances on Helge Lien’s double album “10” and to Youth Lagoon’s album “Heaven is a Junkyard”, and I enjoyed the Silver Solids a lot. They had an obvious tonal advantage over the silver-coated Audiocrasts and presented the music in a livelier fashion than even the Symphonic Line cables. When it came to maintaining order and proportion, however, the Symphonic Line’s better shielding proved to be superior.

    The large soundstage effect, which has also been described by Adam LaBarge, could in part be caused by high frequency interference. Although the interference itself was inaudible in line applications, such as CD players with power levels of 2 Volts peak to peak (or 316 mV @-10dBV), it could become directly audible in more sensitive environments. Phono cartridges have a maximum output level ranging from 2 to 7 mV, depending on the cartridge type and model, and RIAA equalised amplification of phono signals is therefore much greater. And even if we cannot easily detect interference in line setups, its effects on music can be heard on the sensitive directional signals that are carried by high frequencies which can, as a result, seem out of place.

    In their price range, Stager Silver Solids are a worthwhile investment. From many perspectives, they can keep up with audio cables many times their price. Because of their thin and rigid nature, they are not always easy to handle behind the rack. Their unshielded design makes them good companions for line operation. Listeners attracted to tonal correctness, dynamics, and detail retrieval will find pleasure with these cables. They are non-fatiguing due to a soft and silky top-end. However, listeners who are particularly fussy about accuracy in soundstage and dimension might be better served elsewhere. I have decided to keep my Stager cables close at hand, for example, to breathe new life into systems lacking in dynamics, detail, and tonality. They sure tickle the senses and make for an overall enjoyable setup.


    • Cable type: Solid-core interconnects
    • Application: Cinch/RCA, line signals
    • Termination: Canare F10, brass core, 24K gold-plating
    • Capacitance (plug): 1 pF, a piece
    • Conductor: 99.9% pure soft-temper 24 AWG solid-core silver (hand-polished)
    • Dialectic: Translucent Teflon (PTFE)
    • Principle: Twisted pair shielding, non-directional
    • Capacitance (cable): 11 pF/ft
    • Cable length tested: 100 cm
    • Position tested: DAC—CD / pre—amp / phono—pre / CD—pre
    • Country of manufacture: USA
    • Year(s): 2000 -

    Photographic images: Stefan Bluhm, 2024

    Digitising Records
  • Let's explore together

    Let's explore together

    Get in touch with me

    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!

    Your contact details

    * Required fields

    All reviews are free of charge, and your personal data will strictly be used to organise the reviewing process with you. Your gear will be returned to you within two weeks, and you are most welcome to take part in the listening process. Gear owners can choose to remain anonymous or be mentioned in the review as they wish.

    Thank you for supporting the eiaudio project.

    Audiophile greetings,