Mad Scientist Audio Heretical PLUS Cables Review

This is a joint review with my dear colleague Kurt Lassen. While I was testing the analogue interconnects, he on the other side tested the digital version of the same cable. When I say “the same cable” I literally mean it. A pair of Heretical Digital Cable+ is exactly what Heretical Analog Cable+ is. 

So in the LISTENING section, you will be reading the opinions of two different writers, mine for the analogue, Kurt Lassen’s for the digital. Most pictures I used are by Kurt Lassen.


Audiophiles love cables. And audiophiles hate cables. 

Being component freaks, audiophiles love every piece of gear that contributes to the sound produced by the audio system and cables are no exception. But in fact cables should not make any contribution to the sound. All they have to do is to get out of the way. The more they get out of the way, the better they are, hence the more they cost. That’s why audiophiles hate them as well. They hate spending a fortune for something that sonically disappears while physically appears in a hefty manner. Cables are also used as tweaks to tune the systems by some audiophiles. They are used for covering any weakness caused by poor matching of audio gear. Whatever reason they are used for, cables are a pain at the neck. Audio world would definitely be better off without cables.

What a cable physically does is to transmit the electric current from one point to another. Some claim that copper is the best conductor to transmit current, others claim that silver is better. Although the discussions haven’t come to an end, at least the options are reduced into two metals in today’s audio world. Then there is the issue of purity of the metal, expressed with numerous 9s. Although 6N (N stands for 9) seems to be the standard, it is threatened by the seventh 9 as some cable producers claim that their conductors have reached the purity of 99.9999999. When purity of metal is concerned, only alchemists can be considered more obsessive than the cable manufacturers. The common assumption is, closer we are to the ultimate purity of metal better is the current flow.


However, if we go a little deeper into physics, we see that when we talk about current, we in fact, talk about the particles that carry charge through wires in a circuit; that are the mobile electrons. When charged, mobile electrons move in one direction. So in physics terms, current is the quantity of charge carrying electrons passing through a cross section of a wire in a time. We can assume that more electrons a conductor’s atoms have (47 for silver, 29 for copper), higher is the current rate. Although not all electrons are mobile –only the valance ones are, meaning the ones in the outer orbit– we can also assume that silver is a better conductor in terms of current flow, as it has more valance electrons. Well, not wrong, but not a fact either when it comes to its relationship with better sound. It is an assumption. So let’s go a little deeper. 

Electrons carry charge with a net drift. But since we don’t live in a two dimensional universe and every substance has a volume, that is, every atom or molecule of a conductor is surrounded by other atoms and molecules of the same kind and so is every electron, physical phenomena do not occur on a linear plane. The path of a typical electron through a wire could be described as a rather chaotic, zigzag path characterized by collisions with fixed atoms. Each collision results in a change in direction of the electron. Yet because of collisions with atoms in the solid network of the metal conductor, there are two steps backwards for every three steps forward. 

The overall effect of the countless collisions is that the overall drift speed of an electron in a circuit is abnormally low. A typical drift speed might be 1 meter per hour. That is so f...king slow! 

Thanks God (weird to use such a phrase when talking about physics), there are many, many charge carrying electrons moving at once throughout the whole length of the circuit. They do not have to travel a long distance in a second, there just has to be a lot of them passing through the cross section (in a 0.01 cm-long cross-sectional slice of a 14-gauge copper wire, there would be as many as 3.51 x 1020 copper atoms, each comprising of 29 electrons. Not all electrons are charge carriers –only the valance ones are– but imagine even just one is a charge carrier, there would be as much as 56 coulombs of charge, meaning 56 amperes/1 sec, within a 0.01cm length of the wire). With that much mobile charge within such a small space, a small drift speed could lead to a very large current. 

Besides, the electric field signal from the source component travels at nearly the speed of light to all mobile electrons within the conductor, ordering them to begin marching. As the signal is received, the electrons begin moving along a zigzag path in their usual direction and in their usual speed. But as all the charge carrying electrons throughout the wire receive the signal almost at the same time, there is almost no time delay between two ends of the cable. Everything happens at a fraction of the speed of light.

So, what’s the outcome of all the above discourse on electrons and charges? The more charge carrying electrons a conductor has –silver in this case– higher is its current rate. But wait! There is already more than enough current in a conductor even if one electron carries charge in a moderate thickness of the material. So what’s the use of charging a circuit with more than enough current? Does it have any positive impact on the end result, in this case sound? Sure it does have a serious effect on the price of the cable, but when sound is concerned, the answer is somewhat equivocal. 

Current rate is not the end of the story. I will not bore you with details, but there are other complications like skin effects, electromagnetic fields, radio frequencies and so on, all affecting the charge carriers. In order to avoid or reduce such effects, cable designers have developed solutions, but every solution comes with its trade off. As a result, cable geometry seems to be as important as the conductivity of the material.

See? There is a lot of science in cable design. And there is also a lot of pseudo-science when marketing is concerned. For the end user who does not have basic physics knowledge, it is easy to believe in assumptions and take them as scientific reality. 


All these physical phenomena theoretically take place in a wavelength that we cannot witness within the limits of our senses, neither with the help of conventional microscopes. Atoms and electrons are much smaller than the wavelength of visible light. In daily life, we witness their existence only by their empirical results. And cable designers test their innovative solutions and the performance of their cables in the empirical world too both by using testing equipment and by ear. Listening seems to be the ultimate testing method as we all have agreed that good measuring equipment does not necessarily sound good, and this we don’t know why. In the end, cable manufacturers charge all their efforts to audiophiles, who are already willing to pay insane amounts of money. 

Can we say all these innovations are really improvements? Or in other words, are the manufacturers’ claims supported by the empirical experience of the end user, in this case listening? Not easy to answer, because listening experience is subjective. When subjective evaluation is concerned, the possibility of bullshitting increases, as it happens in the case of cable-mania –in fact in every kind of “mania”. 

It is easy to talk about audio gear referring to conventional audio terms, but it is hard to accept the fact that these terms do hardly reflect the scientific reality. They are all metaphors to describe sound but nothing else. In fact, no audio gear in the chain has a sound except speakers. I have heard audiophiles claiming how fast their amplifiers or cables perform (whatever that means), and as scientifically explained above, it is bullshit. Charge carriers throughout the whole audio circuit move much slower than a snail. (Actually “fast” is a term for mechanical movement and it is all about the speakers’ drivers.) I have heard audiophiles and manufacturers to claim high conductivity is the key to better sound, and again as explained above, it is just an assumption; if not bullshit. A conductor with even one valance electron can transmit enough charge at a moderate thickness. Notwithstanding, all these assertive, pseudo-scientific propositions are used as marketing arguments to justify the high price tags.

Speaking within the mainstream understanding, better sound quality has its price and regardless of my suspects I stated above, it is not easy to argue with that even for a contrarian like me. As cables are concerned, we all know that what we pay is not for the material only but also for the know-how and creative thinking. So, assumedly manufacturing hi-end cables should not be a game for every Tom, Dick and Harry. But for Bob, it is a game to be played brave heartedly against the legends of the cable world.


Bob is the Mad Scientist. That’s how he introduces himself –his real name is Bob Prangell. He is the founder and designer of Mad Scientist Audio, a small company based in New Zealand, manufacturing cables and tweaks. So where does his “madness” come from? Well, he is a heretic, an opponent to established beliefs and customs of the sacred religion of audio. He uses carbon fibre as the main conductor in his Heretical series of interconnects and digital cables and sells them for real world prices i.e. 1 meter Heretical Analog Plus (HAC+) for US$ 595 and  1meter Heretical Digital Plus (HDC+) for US$ 239, which are subjects to this review. 


HAC+ is the top-of-the-line analogue interconnect cable of Mad Scientist Audio. It uses the same carbon conductor technology as the other Heretical cables, that is, bundles of carbon fibres to carry the signal, but adds a passive copper foil shield and ultra-high quality copper-OCC earth wire. So, what’s carbon fibre got to do with transmitting current? Does it have lower resistance than, for example copper or highly acclaimed silver which is said to have ultra-low resistance to provide better current flow? No! A 1 meter HAC cable has around 37 ohms of resistance which is not even comparable to the aforementioned metals. Bob claims that ultra-low resistance –therefore higher current rate– is not the key to better sound since just about every device used to send current down to an interconnect already has an output impedance of several hundred ohms. And remember the physics lecture above; in carbon fibre, there may already be well enough electrons (it has 4 valance electrons) carrying charge to result sounding good.

Besides, carbon fibre has some advantages against copper and silver. It is immune from skin effects, even up to 250 MHz –a frequency that reduces silver and copper skin depth to a few micrometers. And because of its inherent resistance, HAC+ absorbs any reflections caused by impedance mismatches. But carbon fibre conductor is not the end of the story. As mentioned above, HAC+ is shielded with a copper foil and comprises of a copper earth wire with very low impedance. To my experience with my current reference, low impedance earth wire is as important as the main conductor as it avoids any noise sourced from grounding, especially when used between phono stage and main amplifier.

Coming to the digital, HDC+ is exactly the same cable. One HAC+ is what HDC+ is, or vice versa. That means it is a 37 ohms cable for the digital where the market standard is 75 ohms. Heretical, isn’t it? Nobody asks why the standard is 75 ohms. Well, Bob says there is a very good (!) reason for this –it is written into the SPDIF standard. He claims that 37 ohms resistance helps removing the reflections that occur. A reflection that bounces off the DAC’s input socket will travel the length of the cable and back again, thus experiencing around 75 ohms resistance. 

HAC+ interconnects and HDC+ use KLE (Keith Louis Eichmann) Innovations Harmony range RCA plugs, which to my experience provide very good and tight connectivity. KLEI Absolute Harmony plugs used in HAC+ are made of pure silver and are highly acclaimed by many reviewers for their transparency and musicality. And they are expensive too, selling for AUS$ 149 for a set of 4 in retail. It seems that Bob hasn’t hesitated using high quality parts when designing his top-of-the-line analogue cable. HDC+ comes with KLEI Copper Harmony plugs as standard and can be upgraded to Absolute Harmony while ordering (US$ 299). HAC+ is also available in balanced version with Neutrik XLR plugs. 

Heretical Plus cables have quite a different feel compared to other cables; they tend to be straight all the time. You should be careful when connecting them since carbon can snap if you bend it too far. So you should avoid bending them tighter than 5 inch diameter and you should handle them with the plugs (as recommended by Bob). If you have a tight space between your rack and the wall, you better move everything forward, which may be considered as a disadvantage for some prospect buyers.


I did most of the listening with the Ypsilon CDT-100 CD player, which was directly connected to the Ypsilon Phaethon integrated amplifier with HAC+. I also did some listening with the Unison Research Unico Primo integrated amplifier which was on loan for review. Speakers were Raidho XT-2s, also on loan for review and my own Raidho D2.1s. Finally I tried HAC+ between the Ypsilon PST-100 phono pre-amplifier and the Phaethon, something quite challenging for a cable because of hum issues. All cabling (power and interconnect) was Ansuz Ceramic and for speakers, Ansuz Diamond. 

So what does it sound like? Actually like nothing. Comparing them to my reference Ansuz Ceramics, they have a very similar tonal balance, not as low as the Ansuz Ceramics go maybe, but very well defined. Highs are very transparent to the source, no harshness, no softening, rich and full of information. Mids are open, pleasure to listen to without any superficial emphasis on vocals like some very expensive cables. Compared to my Kimber Select 1030 interconnects (US$ 2.330 in retail), they are far more civilized, getting out of the way elegantly, thus letting the energy of music flow freely, in a way that it never jumps on you. When I returned to the Kimbers during the comparison session, they sounded harsh and rude to my ears and I disconnected them immediately, as my ears refused to investigate any further. In HAC+, I found most of the qualities that I like about Ansuz Ceramics, maybe except loads of air and depth that come approximately for 7 times of the price (euro 3.800 in retail). I do not mean that HAC+ lacks air and depth. In fact, there are plenty of both and the overall presentation is simply amazing for the price. But Ansuz is something else in this is aspect and in complex passages of orchestral music, you understand what they stand for. On the other hand, if you don’t have a very revealing system, this may not mean a lot for you and you may even prefer HAC+.  

In the beautiful Chesky recording of Fred Hersch Trio Plays (numerous legends of jazz from Coleman to Strayhorn), Tom Rainey’s drum appears in the right scale, his harsh strokes on cymbals and snare drum in certain tracks sounding realistic, full of energy without any hint of harshness. Metal sounds like metal (more vibrant metal tone than many cables that I tried at home), wood sounds like wood. The piano notes are elegantly presented, transmitting Fred Hersh’s flawless technique. Double bass is articulate and well textured. Overall, HAC+  gives all the justice to this beautiful recording.

In the DECCA recording of Vladimir Ashkenazy playing Rachmaninov Piano Concertos 1-4 (London Symphony Orchestra Conducted by André Previn) the beautiful tone of Bösendorfer piano (I guess it is Bösendorfer) is reproduced with energy, reminding one that piano is a percussion instrument in fact, especially in the opening of concerto No.1in F sharp minor. Sharp strokes of hammers on the strings come with all the energy. The orchestra behind the piano is laid as wide as it goes, not as deep as I am used to maybe, but this I only realised in comparison with Ansuz Ceramics while sitting in the listening position (something that I rarely do). 

Mahler’s Symphony No.5 (Royal Concertgebouw Orchestra conducted by Riccardo Chailly, DECCA) is my typical torture test for many audio gear as well as the cables. HAC+ easily handles the complex passages with confidence, transmitting the energy of the brasses with beauty and grace. This I really credit very much as with most cables brass instruments in complex passages sound harsh, if not, then rolled off losing their vibrant characteristics. Same is true for cymbals in crescendos. For a cable at US$ 600 range, I would call its performance simply impressive. Ok, with Ansuz Ceramics those crescendos raise with more authority and refinement. But when I listened to the same passages with Unico Primo, I was not able to point out the difference that easily. Again, it’s all about how revealing your system is.  

I finally tried HAC+ between my Ypsilon PST-100 phono preamplifier and the Phaethon integrated amplifier. Among all the cables I had tried, Ansuz was the only one that avoided hum between the two. Honestly speaking I was not expecting a hum free performance from a cable at this price range, but HAC+ proved to be the opposite. The system played dead silent with HAC+, bringing hours of listening pleasure as I kept it connected there to listen to some of my LPs whose highs sounded (to my ears) a bit more laid back than they should be.

Overall, in my system and in my listening conditions, HAC+ proved to be a great cable with a musical performance far above its price. I will not hesitate to say it may easily outclass many legends of the high-end cable world.


Below is the text I received from Kurt Lassen on HDC+. It has been almost a month since he finished his review. Unfortunately it took me more time to finalize mine. He is a proud daddy for more than 4 months now and I guess he will find more time to deal with audio. I insert his text here without touching a word. 

My dear colleague at Ahmet Kip has just received another bunch of the Mad Scientists Audio cables from New Zealand for a more in depth review. And as I am a proud daddy for 120 days now, my role as a HiFi predict and reviewer is diminished as to say the least, so only a few words and some listening impressions from me. The rest Ahmet will take good care of.

Some of my notes written on my iPad while listening:

“…And The World Laughs With You” with Flying Lotus featuring Thom Yorke from the album Cosmogramma is an electronic musical masterpiece, with the deep bass lines coming to life and vibrancy via the HDC+ cable. Great sound, and addictive to say the least. The new HDC+ cables gives the listener a  great sound staging as well as the artificially created instruments sounds very realistic!

Or check out Keith Richards song “Illusion” with my number one bass player Pino Palladino. On this song the whining guitar and the artists smokey voice absolutely gets to your heart. Norah´s Jones´ additional vocals makes the track definitely a favourite of mine. The drums and the piano also lets you get the impression that this song is recorded in a smokey old western saloon. Too bad it fades out after 3:48 minutes already. With the HDC+ cables I just enjoy the music, and love the authentic illusion (pun intended) of the recited music.

“Love Hurts” with Nazareth from the 70´s is also a winner with this cable. It´s easy to hear the reverb on the tambourine on the drummers counting on “2”, as it is on the singers voice. And even as it´s an old recording, when listening with the HDC+ the music just flows beautifully from the speakers.

Voices are soft and solid while listening with this cable. Try listening to the new Danish artist Black Dylan´s album Hey Stranger. Listen to the track “The One” or “She Said I Was A Failure” and get your kicks and be transformed to the 1930´s and having a movie playing on your inner wide screen inside your head.

From my colleagues at Stereophile I just read about the album Just The Way That I Am by artist Dave Insley. I cued it up on ROON and just loved the violins and the piano on the track “Everything Must Go”. A great Country and Western style that reminds me a lot of Johnny Cash and the likes. The brushes of the snare drum are soft, and the image depth is very, very good with this Mad Scientist cable. You can easily compare it to cables costing 5-6 times the price.

“Come On” by Lucinda Williams also comes as soft as a summer breeze with he HDC+ cable. Not one negative word to say about this cable!

Generally speaking bass notes are very articulated, deep and yet very, very precise. With the HDC+ the low energy in the listening room is better, way better then with cables from other brands I had at home. Depth and spaces and multiple musical layers are so clearly and precise, yet soft as a baby´s skin. The sound of this cable, and maybe due to it´s carbon fiber structure, reminds me of adding the UpTone Audio REGEN to the computer rig, and the ability to play MQA files (with the Meridian Explorer2); they both make the sound less digital, but much more addictive. This HDC+ cables does the same, it transformes the sound into music. Oh boy I am hooked, this HDC+ is good, worldclass, and can beat anything five or ten times it´s price. Yes it´s THAT good.

I can easily compare the HDC+ to the “old” HDC digital cable from the same brand. The differences are clear and obvious. With the new PLUS cable the listener is benefitted with an even more likable, precise, smooth and deep soundstage. As much as I absolutely love the old HDC version (only maybe 6 months old) of the Mad Scientists Audio´s digital cable, I dearly adore the new one even more, much more. The low end is coming out of the speakers with much more authority. You just get the grip of more bass, and bass with much more definition and substance. Also the smallest details are heard. The depth of the soundstage is bigger, better and more precise with the HDC+ then ever heard before. Instruments just float in the soundspace - it´s very addictive to say the least.

Try to listen to the bass lines on Peter Gabriel’s “Sledgehammer” (for a closer look at how Tony Levin´s actually plays the bass lines, join in at: link.

I´d say: this is the new stuff, I go dancing in. HDC+ goes deep and wide, nice and dry. Soft, smooth and precise.

Another good thing is, before you worry about your hard earned money, that the Mad Scientist gives you the chance of using their 30 days money back guarantee - but you won´t use it, trust me!

Note by AK: Although I did not do intensive listening, my initial findings on HDC+ support Kurt Lassen’s. If I were into digital like Kurt, I would definitely keep it.


During the review period, I never felt as if something was missing or disturbing with the music, so I kept the HAC+ connected to the system all the time, either to listen to CDs or LPs. There were times when I listened to the same tracks for the second time with HAC+ connected just for my own pleasure. And there were times I tortured it testing against Ansuz Ceramics with complex orchestral music where in comparison my ears preferred just a bit more body, more air and more depth provided by my reference cables. I know such comparison is not fair, but fairness is a normative concept and has nothing to do with reality. I also know such preference is subjective and very much related to the system. Then there were also times I preferred HAC+’s comparatively more forward and energetic presentation with some laid back recordings. But, in whichever condition I listened to it or tested it against my references, HAC+ stood still with dignity, never letting the music down.

In a market where everything comes as a fetish object either in terms of price or cosmetics, HAC+ is a real heretic. Its modest look and price will not appeal most high-enders. They will continue searching satisfaction in the high market idols of the sacred audio religion. They will justify the insane amount of dollars they pay for a meter with nicely polished marketing bullshit based on pseudo-science. They will be talking about theories that they do not deeply understand. And beware! They can even be claiming that they hear such tiny nuances which in fact only true connoisseurs would hear and value. 

Of course there are cable manufacturers –although very few– who invest a lot for trying to reach the ultimate sound reproduction and their sincere efforts can only be admired by the true enthusiasts or connoisseurs of audio, not by everyone who can afford. The truth is; for many, it is not easy to differentiate a good sounding cable from an expensive one (Ok, I know, cables do not sound). The difference is very much like a good Prosecco vs. Champagne. Something a true enthusiast will point out. And a true enthusiast will also admire the former as much as the latter. 

In my opinion, Mad Scientist Audio HAC+ will give you more musical pleasure than many champagne level high-end cables. So, here is another good reason for me to applaud heresy. I applaud Bob Prangell not only for his contribution to better sound but for his courage to destroy the beliefs of the sacred audio religion. If heretics did not exist, the world would be a disaster for the sceptics like me.

Very sincerely and heartedly recommended for true enthusiasts. 

© Ahmet Kip Text and photos 2016
© Kurt Lassen Text and photos 2016