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Power amplifier



Price (at the time of the test): 74 900 PLN

Contact: 2-14-10 Shin-ishikawa
Aoba-ku Yokohama | 225-8508 | Japan
tel.: +81-45-901-2771


Product delivered for test by: NAUTILUS


ome devices are able to fit into particular audio system seamlessly, like they have always been a part of it, as if they've always belonged. They fulfill sonic character of this system, allowing its user to elevate his level of music perception by adding some elements he hasn't even known existed. That sound serious, right, especially because it suggests that I mean top high end systems. The beauty of this job, of my job, is that I'm having such moments of “enlightenment” again and again, because there are always new devices that sound better than others. And each time one discovers such a better performing device, one discovers even more new elements in system's presentation, in “more music in music”. These device that “fit” into particular system best compliment it, make it perform in a better, more interesting way. And it does not matter how much such a device costs.

In my case many times it so happened that when I discovered such devices I treated them as a natural part of my system, I used them while reviewing other product, often forgetting to review these very special ones, as they'd become just another “natural” element of my reference system. I'd like to change that. Already for some time now I've been trying to share such discoveries immediately with Readers all magazine I write reviews for, which mean of „High Fidelity”, „”, „Positive Feedback Online” and „”. I try to inform them/you how good these devices are, how much they mean for me.

Sometimes though, some products slip through – like Soulution 710 amplifier (an element of my reference system) few years ago, and like Accuphase A-70 now, another power amplifier, that we have been using for quite some time already in Tomek's system during our Cracow Sonic Society meeting. My own amplifier already has a successor, Soulution 711, and I hope to check it out really soon, but the Accuphase hasn't been on the market that long.

In 2012, celebrating its 40th anniversary, Accuphase presented A-200 monoblocks, operating in Class A. At the time I reviewed them for „Audio” magazine and I found out that it was the first class A Accuphase amplifier I could live with. It offered amazingly deep, tuneful, well differentiated sound and it wasn't overly selective. Japanese manufacturer decided to use many solutions that were developed for A-200 also for the new A-70. Despite the similar looks with previous stereo flagship, A-70 is a completely new device, not just an “upgraded” version of the predecessor. Manufacturer declares that: „In short: A-70 is a stereophonic version of A-200 monoblocks delivering less output power.”

Manufacturer managed to improve all measurable parameters, including these, that are usually not even considered, that are an effect a a better mechanical design. A-70 sports a discreet ultra-low-noise „instrumentation amplifier” in the input stage, that results in -127 dB (gain = -12 dB) S/N ratio. Output stage uses MOSFET transistors – each channels sports 10 of such transistors working in push-pull configuration in a pure A class. In the output circuitry, ultra-heavy-gauge edgewise coils with a surface area more than three times larger than conventional units, combined with MOS-FET switches are used in place of relays, to eliminate mechanical contacts and improve long-term reliability. Top-grade materials, sophisticated circuit pattern technology, and various other measures result in low impedance and enable the realization of a damping factor of 800, which represents a two-fold improvement over the A-65.

ACCUPHASE in “High Fidelity”
  • KRAKOW SONIC SOCIETY, meeting #95: Accuphase DG-58 | Jim S. Saito, Mark M. Suzuki, Tatsuki Tozuka, Kohei Nishigawa in Cracow, read HERE
  • INTERVIEW: Jim S. Saito, Yasumasa Ishizuka, Tatsuki Tozuka, read HERE
  • HYDE PARK: Accuphase – wczoraj, dziś i na zawsze (Accuphase – yesterday, today and forever), read HERE
    Integrated amplifiers:
  • TEST: Accuphase E-600 – integrated amplifier, read HERE
  • TEST: Accuphase E-250 (vs E-260) – integrated amplifier, read HERE
  • TEST: Accuphase E-250 - integrated amplifier, read HERE
  • TEST: Accuphase E-360 - integrated amplifier, read HERE
  • TEST: Accuphase AC-5 – turntable cartridge, read HERE
  • TEST: Accuphase C-27 – phono stage, read HERE
  • TEST: Accuphase C-3800 + M-6000 - preamplifier + power amplifier, read HERE
  • TEST: Accuphase C-2810 + A-65 - preamplifier + power amplifier, read HERE
  • TEST: Accuphase C-2110 + P-4100 – line preamplifier + power amplifier, read HERE
  • TEST: Accuphase C-2410 - line preamplifier, read HERE

    Power amplifiers
  • TEST: Accuphase A-60 – power amplifier, read HERE
  • TEST: Accuphase P-7100 - power amplifier, read HERE

    CD | SACD players
  • TEST: Accuphase DP-720 - Super Audio CD player, read HERE
  • TEST: Accuphase CD DP-400 | Accuphase CD DP-510 | SACD Accuphase DP-700 – CD | SACD players, read HERE
  • TEST: Accuphase DP-700 – SACD player, read HERE

  • Recordings used during test (a selection)

    CD | SACD
    • Doris Drew, Rarities, Sinatra Society of Japan XQAM-1054, CD (2012).
    • Miles Davis Quintet, Cookin’, Prestige/Analogue Productions CPRJ 7094 SA, SACD/CD (1956/2014).
    • Charlie Parker, Charlie Parker , Clef/UMG Recordings UCCV-9478, „David Stone Martin 10 inch Collector’s Selection”, CD (1952 | 1953/2013).
    • Cyrus Chestnut, Midnight Melodies, Smoke Sessions Records SSR-1408, CD (2014);
    • NEU!, NEU!75, Brain Records/P-Vine Records PCD-93529, “NEU! Story 3”, CD (1975/2001).
    • Vangelis, Spiral, RCA/BMG Japan 176 63561, K2 SHM-CD (1977/2008).
    • Duke Ellington, Masterpieces by Ellington, Columbia/Analogue Productions ML 4418, 200 g LP (1951/2014).
    • Budka Suflera, Giganci tańczą, Polskie Nagrania MUZA SX 2293, LP (1986).
    • Helmut Nadolski, Meditation, VeriTon SXV-786, LP (1976).
    • Skaldowie, Rezerwat miłości, Polskie Nagrania MUZA SX 1796, LP (1979).
    • Elvis Presley, Recorded Live On Stage In Memphis. 40th Anniversary edition, RCA Records/Music On Vinyl MOVLP1052, 4 x 180 g LP (2014).
    • Charlie Haden, The Private Collection, Naim Label LP110, 3 x 180 g LP (2007/2008).
    • Nat ‘King’ Cole and the Trio, After Midnight, Columbia/Analogue Productions 28180, 3 x 180 g 45 rpm LP (1957/2010).
    Japanese CD editions are available from

    Do we even need CD and vinyl in XXI century? Today, they might seem obsolete – many people buy files, instead of physical medium, lots of them buy single pieces of music, not whole albums anymore, and finally there are more and more streaming services that allow not to download music to HDD at all. One might say that history made a full circle, as it all started with listening to the music on the radio. The only difference is that today one might “listen to the radio” one created a playlist to be played for.

    And yet I'm pretty sure that physical for of music album will survive, just as novels survived despite the fact that already 10 years ago some claimed that these would vanish completely. I guess a lot of credit for that fact has to go to the vinyl renaissance and its beautiful, large covers. Vinyl record forces user to listen to, at least, full side of each record, without choosing particular pieces of music, going forward and backward. It's a good tradition, we should not give it up.

    Going back to the initial question – do we even need CDs and vinyl records today? Or why do we need them? I thing one of the best answers is very simple: for emotions. Music as such is able to involve listening emotionally in such a way no other form of art can. It “induces” emotions in connection with particular events, people, places, experiences, but also totally new, fresh ones. We all have our favorite tunes, melodies, songs, albums that remind us some particular events or experiences from our past. Music allows us to relive them preventing a loss of these memories.

    Accuphase A-70 seems to help listener to achieve just that. It delivers music in such a way that it makes one WANT to listen to the music, that one NEEDS to listen. All I needed to know, that Tomek made a great choice buying this amp, was just one pieces of music. A-70 has no problems driving quite difficult Dynaudio Confidence C4 Signature speakers in a large room also with large distance between speakers and listener. A-70 delivered amazingly effortless, seamless performance.

    Y listening room isn't exactly what you might call: “by the book” - it is quite large but its shape is irregular, my speakers are relatively easy to drive and I sit quite close to them. That is why even when I wanted to crank up volume when listening to bass-rich music, like Vangelis' Spiral for example, I never used more that 10W of output power of my amp, and the average power used during my listening sessions was around 5-6W. 3W were more than enough when it came to listening to live, hardly compressed, jazz music of Cyrus Chestnut from his album Midnight Melodies recorded in Smoke club. Let me use this opportunity to share the news of new Smoke Sessions release called Night And Day by Vincent Herring that shall be released on May 12th (more HERE). I've already order a copy and I encourage you to do the same.

    Output power is a relative term, no matter what engineers tell you. Relative means that... it depends on each and every particular case. I had a chance to test in my setup some 5 to 15 W tube amplifiers, some of them were remarkable. To name just the most important ones: Reimyo PAT-777, Ancient Audio Silver Grand Mono, Triode TRX-M300 Reference Edition. Each of them offered something special, something that none other amp with high output power, tube or solid-state, was able to re-create. But all of them showed some downsides of a low output power too.

    Only such powerful beasts like Soulution 710, Accuphase A-200, and now A-70 proved that when wanted to use such a large speakers like mine, and wanted to achieve a realistic “picture” of a grand orchestra, or play rock and electronic music in a convincing way (meaning in a similar way to what one remembered from concerts) these speakers had to be driver by amplifiers with high output power. In fact it was not even about actual output power used (in case of Accuphase displayed on the front) but about how much headroom such an amp offered. One would get very different results when combining an amplifier using 90% of its power to drive particular speakers, and another that would use only 9% of its potential while delivering the same amount of power. The same output power would be used but the result, the performance would be very different. That's what this Japanese amplifier will provide its user with, I can't even imagine that any user could “lack” more power from this device. Sure – A-200 will deliver large phantom images, they will do it with even greater ease. Their performance will be more sophisticated, more subtleties will be conveyed, greater spacing, more air between instruments. But A-70 doesn't fall far behind in any of this sound features, one couldn't just call it a “cheaper” solution.

    So the output power is not that important per se. In this particular case it serves the purpose of creating large, palpable phantom images. It helps to easily reproduce a wonderful tonality. Someone who has no experience with this type of sound might, for a long time during first session, think, that Accuphase is focused solely on midrange presentation. Sound is very rich, dense with a very palpable rendition of the foreground of the stage. It is how a sound of many 300B SETs is perceived. Not because it is actually so, but because usually it is the midrange that is the richest part of the range, and both extremes are perceived as slightly rolled-off because they not that rich as the midrange is. Or, in other words, we one perceives midrange presentation as better than the one of range extremes.

    We, humans, are “shaped” this way by evolution, we are more sensitive to this part of the range, that covers human voice, that allows us to differentiate subtleties in somebody's voice tone. That is why it is easier to tell, whether there is some coloration to vocal, than it is to cymbals (for example). So once one hears such a refined presentation of midrange, as A-70 offers, one one get fixated on this element, it “sets” the whole perception.

    But the fact is that Accuphase does not emphasize midrange – it offers very coherent sound throughout the whole range, from the very bottom to the upper treble. It delivers rich, open, dynamic performance with a lot of drive. It is slightly warm, but accurate. There is no emphasis on an attack phase, there is no exaggeration is sounds definition. Maybe that is why for the most time listener might be under impression that he listens to a low-power tube amplifier. When I heard Niemen sing, either from the first pressing LP, or the latest, digital one remastered by Ms Atalay, he sounded very natural, he never “screamed”. I had similar impressions when listening to Doris Drew Rarities, and even to the last Cohen's album, Popular Problems.

    Such recordings, made many years ago when recording technique was that perfect, when performers and sound engineers had a different kind of “artistic” vision, might sound bit bright, or harsh, they often lack richness. To enjoy them to the full extent one needs an amplifier, that offers such a richness, density of the midrange, as the reviewed Accuphase does. Midrange has to be very natural, rich, but without coloration. Obviously there always are some limitations to what any audio device can do with such recordings, but some, within these limitations, are able to deliver all the information about music and recording in a way that allows listener to enjoy listening to it. I found it fascinating, that with this Accuphase I could choose any recording knowing, that it would sound good.


    I didn't want this review of A-70 to be a list of pros and cons and features. Surely you will find all of them in this text. Sound is rather warm, and a definition of both range extremes delivered by twice as expensive A-200 was better. My idea was to convey to you how remarkable, how beautifully, organic sounding amplifier this Accuphase was. It allowed me to enjoy any music, listening was a pure pleasure.

    It sports enough power to fill a large room with sound, and in smaller rooms one will enjoy large power headroom. Such a headroom is a truly wanted feature in audio world. Fit and finish are, as always in case of Accuphase, perfect. User will surely appreciate an advanced protection circuitry, and features that allow to “adjust” this amplifier to a particular system and to particular sonic preferences. This is a true high-end, with a human face. Truly wonderful sound! RED Fingerprint.

    A-70 was compared head-to-head with twice as expensive, reference power amplifier, Soulution 710. I placed it not on Finite Elemente Pagode Edition, but on Acoustic Revive RST-38H platform. The Harmonix TU-666M Million anti-vibration feet allowed me to achieve a more precise sound. Amplifier worked in almost identical system as the one I used some time ago when reviewing A-200 monoblocks for “Audio” magazine. I had a chance to listen to A-70 also in Tomek's system, where it works with reel-to-reel Nagra tape recorder (and master-tapes) and a prototype of Ayon Audio's S5 player, that allowed us to listen to “Master” quality DSD files.

    For this test I used as a source not only my reference Ancient Audio Lektor AIR V-edition CD Player, but also the TechDAS Air Force Two turntable with ZYX Ω Premium Diamond cartridge and ZYX Premium Artisan phonostage. Ayon Audio Spheris III preamplifier was connected with Accuphase using Acoustic Revive XLR-1.8PA II interconnect. To power the device I used Acrolink Mexcel 7N-PC9500 cable. I used A-70 also for a test of Harmonix X-DC SM Million power cable, that was compared to Crystal Cable Absolute Dream. Changes that all these cables introduced were very clear to me and I could easily determine a sonic character of each of them. I listened to all version of Niemen album using this setup and it allowed me to assess differences between them.

    An Owner of A-70

    I bought Accuphase A-70 without even checking it out first. As an owner of A-46 model I always dreamed about having it's “older brother”, A-65, that I saw each time on a shelf when I visited showroom. Some day, beginning of 2014, I saw on Twitter a picture of to be released new model, A-70. I knew already then that it was a perfect moment for an upgrade of my system. Obviously I realized that buying and amplifier without checking it first out in my own system wasn't optimal, but I also knew that the general direction Accuphase showed by its other recent products like: A-200 or E-600, minimized the risk to almost 0. Without much hesitation I visited distributor, paid some advance and later, middle April I became one of the first owners of A-70 in the world.

    All I needed was just a few first seconds to realize how wrong I was believing that A-46 was enough to drive my large Dynaudio Confidence C4 Signature speakers in a quite large room. Even though my new A-70 was brand new I immediately heard lowest notes that I hadn't heard before. Impressive damping factor of guaranteed value of 800 (in reality it is most likely even higher) allows a full control over speakers, it ensures enough headroom for any music piece, even the most demanding ones.

    This feature plus some other like: coherency, wonderful timbral expression, large, deep, multi-plane soundstage, naturalness of midrange make A-70 almost a perfect amplifier. Its appearance is another attitude – it is not a monster, like many other high-end amplifiers available on the market but it is big, it is solid, heavy, offers great finish, handles fixed to the front, and wonderful displays. It is an amplifier I've always dreamed about. In my humble opinion, and let me assure you that my motivation is not a justification of a significant expense, A-70 represents the same level of performance and appearance as products of such renown brands as: Soulution, Vitus, DarTZeel or Dan D'Agostino (and yes, I had a chance to listen to all of them).

    I think that this review of Accuphase A-70 is a great opportunity to share quite an unusual story with you. A friend of my from Stargard Gdański came to visit me one Friday in December 2014. He came to Cracow planning to purchase A-70, that he'd never had a chance to listen to before. Up to this day the only common element of our systems were Dynaudio Confidence C4 speakers. He used with them an integrated amplifier and CD Player, both by Accuphase. He thought (and it as a great idea) that it would be more convincing, more reliable to listen to this amplifier with exactly the same speakers he used and to do it rather at friend home than in distributor's showroom.

    We listened to the music for several hours, despite the fact that my friend knew he wanted to buy this amp already after first hour, so it was very late when I finally went to bad. Roughly after 3 hours of sleep I was woken up by music coming from my listening room. I wasn't particularly happy about it, I went down to the room and found my friend totally immersed in music. After few more albums he finally concluded: “I take it all, whole system”. We ate breakfast and then went to Nautilus showroom where he bought A-70, Ayon CD-T CD transport and Ayon Stratos preamplifier/DAC.

    That is a story of another “twin” system that is still used in Northern Poland. Let's be honest – I don't think many would buy this exact setup. I built it and I am very proud of it as well as the fact that other audiophile voted for it with his own money. Despite the fact, that it happened half a year ago, Łukasz keeps calling me twice a week to praise his remarkable system and to tell me how many audiophiles from his region already visited him to listen to this setup. Obviously a lot of credit for a success of this system has to go to Accuphase A-70.

    Downsides? For the first few days the „Eco Mode” really got on my nerves. This function turns amplifier off after two hours on inactivity. It took one phone call to distributor to learn how to turn it off, but on the other hand I'm not particularly happy that I had to pay for a function that I do not want to use. I do realize that Accuphase did what they had to do due to regulations created in Brussels to make our lives more difficult (the first of such a “great” regulations I remember they introduced in the late 90ties was a ban for speaker posts that accepted banana plugs). This function that switches Class A amplifier off is, in my opinion, as absurd as bi-turbo, 1,2 L engines for class D and E limousines.

    A solid body of A-70 will stand out in every room. The appearance is a “classic” Accuphase with golden anodized aluminum front, with LED indicators of an input signal level (in dB), and a LED display placed above, that shows information about power output (in W) and finally with huge radiators on both side walls.

    The front panel holds also an on/off switch and a few LED indicators, that indicate a selected input (XLR/RCA), and a mode amplifier works in (when it works as a monoblock an indicator „Bridge” is on. It seems that this all there is, at least until one won't lover a flap and finds a lot of buttons and switches underneath. Accuphase has been using this solution for some time for their integrated amplifiers. This way front panel looks very neat but the device still offers an abundant functionality.

    Using one of the switches user might choose which indicators should work, or even turn them off. After some time I decided to turn them off as these blinking LEDs distracted me when I listened to music. There are three other switches that allow user to choose a “sensitivity” of indicators. One can select active input and input sensitivity. When using the latter, manufacturer recommends to put it is such position that to listen at “normal” volume level one would put a volume knob midway of the scale. This way the noise of the whole system should be at optimal level.

    An internal design looks, as always when it comes to Accuphase products, fantastic. A precise, solid make, it looks like it is supposed to last not 10 but 100 years. In the middle there is a huge, shielded power transformer. The shielding “cup”, reinforced additionally with aluminum fins acts also as a radiator. There are two large, 82 000 μF filtering capacitors in power supply. These are connected with two thick, gold plated jumpers (rather than cables). Also ground bars and most of contact elements are gold plated. Capacitors were made for Accuphase by Nichicon.

    The input section sits on a separate board. There is a buffer based on transistors, as well as as a balancing circuit (for RCA inputs) – A-70 is a balanced design. Also current section consists of transistors. It sports 10 pairs of transistors working in push-pull configuration in Class A, per channel (complementary pairs of Toshiba J618 + K3497, so called „Junction FET”). Accuphase’s original MCS (Multiple Circuit Summing) principle uses a number of identical circuits connected in parallel. Accuphase calls this solution: MCS+ (Multiple Circuit Summing) and it has used it, not only for amplifiers, for many years now. It allows to minimize noise and harmonic distortion. The A-70 uses the output signal current rather than voltage for feedback.

    The newly adopted ultra low-noise instrumentation amplifier principle is realized with discrete components, allowing optimization of the redesigned signal input stage and power amplification stage, and resulting in a 6 dB improvement in signal-to-noise over the A-65. Manufacturer changed a configuration of gain stages compared to previous model, Before the input stage's gain was x 4 and the next stage was x 6,3, which in result offered (max) 25 dB gain. This time the input stage offers x12,6 (22 dB), and the second stage only x 2 (6 dB).

    The chassis is made of metal profiles and radiators bolted together. Feet are made of steel with a significant percentage of iron. Accuphase claims that this set of materials improves resonance damping.

    Pure perfection.

    Specifications (according to manufacturer)

    Output power (continuous):
    60 W/8 Ω | 120 W/4 Ω | 240 W/2 Ω | 480 W/1 Ω
    Output power (peak):
    131 W/8 Ω | 232 W/4 Ω | 370 W/2 Ω | 547 W/1 Ω
    -121 dB (guaranteed)
    -124 dB (typical)
    Damping factor:
    800 (guaranteed)
    1000 (typical)
    Dimensions: 465 x 238 x 514 mm
    Weight: 44,3 kg



    - Turntable: AVID HIFI Acutus SP [Custom Version]
    - Cartridges: Miyajima Laboratory KANSUI, review HERE | Miyajima Laboratory SHILABE, review HERE | Miyajima Laboratory ZERO (mono) | Denon DL-103SA, review HERE
    - Phono stage: RCM Audio Sensor Prelude IC, review HERE

    - Compact Disc Player: Ancient Audio AIR V-edition, review HERE
    - Multiformat Player: Cambridge Audio Azur 752BD
    - Line Preamplifier: Polaris III [Custom Version] + AC Regenerator, regular version review (in Polish) HERE
    - Power amplifier: Soulution 710
    - Integrated Amplifier: Leben CS300XS Custom Version, review HERE

    - Stand mount Loudspeakers: Harbeth M40.1 Domestic, review HERE
    - Stands for Harbeths: Acoustic Revive Custom Series Loudspeaker Stands
    - Real-Sound Processor: SPEC RSP-101/GL
    - Integrated Amplifier/Headphone amplifier: Leben CS300XS Custom Version, review HERE
    - Headphones: HIFIMAN HE-6, review HERE | HIFIMAN HE-500, review HERE | HIFIMAN HE-300, review HERE | Sennheiser HD800 | AKG K701, review (in Polish) HERE | Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, version 600 - reviews (in Polish): HERE, HERE, HERE
    - Headphone Stands: Klutz Design CanCans (x 3), review (in Polish) HERE
    - Headphone Cables: Entreq Konstantin 2010/Sennheiser HD800/HIFIMAN HE-500, review HERE

    - Portable Player: HIFIMAN HM-801
    - USB Cables: Acoustic Revive USB-1.0SP (1 m) | Acoustic Revive USB-5.0PL (5 m), review HERE
    - LAN Cables: Acoustic Revive LAN-1.0 PA (kable ) | RLI-1 (filtry), review HERE
    - Router: Liksys WAG320N
    - NAS: Synology DS410j/8 TB
    System I
    - Interconnects: Acrolink Mexcel 7N-DA6300, review HERE | preamplifier-power amplifier: Acrolink 8N-A2080III Evo, review HERE
    - Loudspeaker Cables: Tara Labs Omega Onyx, review (in Polish) HERE
    System II
    - Interconnects: Acoustic Revive RCA-1.0PA | XLR-1.0PA II
    - Loudspeaker Cables: Acoustic Revive SPC-PA

    System I
    - Power Cables: Acrolink Mexcel 7N-PC9300, all system, review HERE
    - Power Distributor: Acoustic Revive RTP-4eu Ultimate, review HERE
    - Power Line: fuse – power cable Oyaide Tunami Nigo (6m) – wall sockets 3 x Furutech FT-SWS (R)
    System II
    - Power Cables: Harmonix X-DC350M2R Improved-Version, review (in Polish) HERE | Oyaide GPX-R (x 4 ), review HERE
    - Power Distributor: Oyaide MTS-4e, review HERE
    - Stolik: SolidBase IV Custom, read HERE/all system
    - Anti-vibration Platforms: Acoustic Revive RAF-48H, review HERE/digital sources | Pro Audio Bono [Custom Version]/headphone amplifier/integrated amplifier, review HERE | Acoustic Revive RST-38H/loudspeakers under review/stands for loudspeakers under review
    - Anti-vibration Feets: Franc Audio Accessories Ceramic Disc/ CD Player/Ayon Polaris II Power Supply /products under review, review HERE | Finite Elemente CeraPuc/ products under review, review HERE | Audio Replas OPT-30HG-SC/PL HR Quartz, review HERE
    - Anti-vibration accsories: Audio Replas CNS-7000SZ/power cable, review HERE
    - Quartz Isolators: Acoustic Revive RIQ-5010/CP-4

    - FM Radio: Tivoli Audio Model One