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This review first appeared in the August 2008 issue of and can be read in its original German version here. It is herewith translated and presented to an English-only audience through a mutual syndication arrangement with As is customary for our own reviews, the writer's signature at review's end has a link below it to his e-mail should you have questions or feedback you wish to send. All images contained in this review are the property of or Abacus Electronics. - Ed.

Reviewer: Martin Mertens
Digital Source: Creek CD 43 Mk II
Amplification: integrated - Jadis Orchestra black/silver
Loudspeakers: Expolinear T 120
Cabling: low-level - Vampire CC; high-level inakustik
Review component retail: €530

Dwarf uprising
My original plan was to review the Abacus Rieder Ampino in the context of "small amps" together with the NAD 315 BEE and Onkyo 9355. But certain things intervened. For one, the Ampino arrived significantly delayed despite having been received in plenty of time at fairaudio. Colleague Dames simply had a hard time letting it go. Thus the Ampino arrived when I was essentially done with the NAD and Onkyo. What's more, the moment I fired the Ampino up, it was clear that it performed in an altogether different league than the two entry-level units. To be fair, the Ampino's €530 sticker quite exceeds the earlier review's 350 to 400 euro window. Now add that the Ampino is really an amp with passive pot. To accommodate various sources like standard integrateds do, you'd need the matching Prepino preamp. In most basic form, this demands another 530 euros. For an uncompromised fair comparison in the above context, the Ampino thus would have to be judged in the 1000 euro price class of integrated amplifiers.

Abacus Electronics
Hence the Abacus Rieder Ampino -- its full name proudly marked on the fascia -- gets its own write-up. That's fitting also considering the firm's history. Abacus Electronics arose from Audio Pro Deutschland which, since 1983, had developed industrial electronics, primarily measurement and controls equipment, energy and analog electronics, electromechanics and -acoustics. For nearly a quarter century then, the Abacus Rieder amplifiers have been a known quantity in "Made in Germany" hifi. That they still suffer exotica status is due to - ahem, individualistic cosmetics that have changed little over the years (more about this anon) and very limited distribution in which direct sales play a considerable role. If you've never crossed paths with an Abacus Rieder amp, it's not surprising even though the firm insists that since 1983, its model 60-120 has found in excess of 10.000 homes. Additionally, the outfit, to my eyes, is managed in a very laid-back and, sorry, home-baked fashion. Simply check out the informative but certainly not high-styled home page. Incidentally, besides amps, the Abacus line-up also includes active speakers.

Rieder amplifier
The basis for all Abacus products is the so-called Rieder amp. During the 80s, Freiburg electromechanical engineer Joachim Rieder developed a new amp circuit whose initial focus wasn't necessarily hifi but controls electronics. In contrast to conventional audio amplification circuits, the Rieder taps its output signal not from the emitter but collector of a transistor. This is claimed to secure maximal current flow regardless of load and to be conceptually related to valve amp technology.

Where have I heard this before - transistor circuits based on valve precedents? With the legendary DIY projects of American amp guru Nelson Pass ( or the solid-state monos M100 by Brit tube pope Tim de Paravicini (google at will). Both instances find transistors in single-ended class A mode, i.e. the earliest of amplification circuits revived to enjoy contemporary applications. Well, let's stay the course. After all, the Rieder has nothing in common with class A SEs of either triode or transistor bend.

Before we get to the innards and acoustic qualities of today's machine, a take on the outsides. There first impressions were split. The shipping carton is relatively small but housed a yet smaller plastic case in which hid the tiny Ampino with power cord and owner's manual. The amp itself recalls kit electronics. Chassis, knobs, the heat sink jutting out the back, the basic speaker terminals (which mandate further comments) all seem to have jumped off the pages of an electronic parts catalogue. I'm undecided whether the final results look more home-brew or like test gear. But let's recall that Abacus's product portfolio does include test and controls gear. Still, without the Abacus silk screen on the face plate, I'd be more apt to mistake the Ampino for a DIY project.

If I called the optics of the earlier NAD and Onkyo machines "understated", what I flash on with the Ampino is "courage". Courage to spend 500 euros on so demure an amp. Courage to incorporate this tiny toy into a serious hifi chain. Courage to finesse thick speaker cables into the minuscule clip terminals while overcoming worries that the heavy wires will turn the small box airborne - or alternately, forgetting about well-worn garden house leads in favor of zip cord (which the maker recommends). Or courage to issue an amp with a protruding heat sink so sharply edged that one can get wounded struggling with the cabling - and which during intensive amp use gets rather more than lukewarm.

About the details: The Ampino consists of a tiny aluminum housing of plates and profiles adding to 25 x 5 x 15.5cm (WxHxD). This approaches the cubic volume of my tube amp's power transformer. If you add the two protruding knobs up front and the heat sink around back, total depth is 21cm. The weight shy of two kilo doesn't impress much either.

The Ampino's front, dedicated as power amp with a single input, merely carries a power mains and volume control, making a source selector redundant. Those knobs look old-fashioned but not enough to qualify as vintage. Adjacent to the power button glows a stylish blue LED to signal work mode. In the middle, two further LEDs signify aberrant behavior. So far, so simple. It's on the business end that things get jammed. An IEC power inlet sits next to four speaker terminals of the most basic kind. Most the space is taken up by the aluminum heat sink which, considering the claimed 50-watt power rating, isn't exactly large. But the more sharp-cornered for it. Clearly this part was originally commissioned for internal use. Next to it is just enough room for a pair of RCA inputs. Here one can connect the matching Prepino preamp to feed various sources. One-source customers with just a CD player for example can go Ampino direct due to the provided passive potentiometer.

A glance under the bonnet surprises. How few parts are needed to make a power amp. All ingredients are cleanly sorted on a circuit board with toroid. No matter how kit the chassis may look, what's inside leaves no doubt as to its professional roots. The board layout is tidy, construction is solid, there's a blue Alps for volume. Here the Ampino looks like a bona fide hifi machine. Were it not for the fuses directly ahead of the output transistors. Aw shucks, with the Ampino you get used to following a different drummer who gives the finger to normal mainstream criteria. Aside from "valve circuit" output transistors (the latter fused) and simplistic loudspeaker sockets, another part of the Rieder amp concept is direct feedback - which might have High-Enders flinching seeing the bad rep NFB suffers in certain quarters. Yet here feedback is viewed as a kind of universal panacea which includes the speaker cables, crossover and voice coil inductance in its loop to eliminate their deleterious effects. So I finally made peace with this amplifier's insistence on following its own lights. Amen.

Though speaker cable quality was said to have no sonic impact, I wasn't prepared to abandon my wiring for zip cord. I thus had to jerry-rig suitable adaptors to run my customary banana-fitted Inakustik Black & White into the spring clip sockets. At least my CD player connected as usual via the RCA inputs. Then it was power-up to insure proper connections. Lucinda Williams' World Without Tears still sat in the spinner (a well-above-average recording by the way) and a few bars later, I'd duly forgotten various errands I'd committed to for the afternoon. An hour and CD passed in a flash. The weighty Country sounds, melancholy lyrics, insistent voice ... I got so completely absorbed in the music as to sorely need something happier next: E.S.T Live in Hamburg. Now usually, I'm no great fan of live recordings. I'd tried more than once before to sit through both CDs here beginning to end, albeit with no success. Yet this time the mere notion of interrupting things didn't even arise. Having to change CDs in midstream was a bother. The music was so compelling. It's rare to find such intensity on a disc. You imagine feeling the same tension that occurred during the session itself; being present during the creation of something phenomenal, between the musicians, between them and the audience. Wow. Urgently recommended if you like Jazz.

Now you expect an en détail rundown of the Ampino's sonics. To be honest, I'm not in the mood because this little amp gets something just so darn bloody right; doing what really good hifi kit does: It puts the music center stage to make it relevant. But if you insist, I start counting the peas. The bass goes low with control but could be blacker and bouncier yet. Could but doesn't have to be. Certain amps create more speed, more explosiveness within dynamic structures. I've even heard amps that were tauter and more controlled. But who needs that? Yet others resolve persnickety detail a few molecules deeper. As though I cared. Basically, I just wanna hear more music.

Overall, the Ampino is ultra neutral to handle whatever musical styles you throw at it. The focus always remains on the music. This includes being able to erect realistic ambience that's dominated by the recording, not the amp. The Ampino allowed me to listen through the most varied of recordings and mostly louder than usual which didn't imply the Ampino couldn't do quiet. But when listening is this much fun, levels automatically escalate. With the Ampino, nothing caved in. Be it Rock or classical, I always felt welcome to get involved. Yet nothing about the amp was artificially seductive. Even long-term, nothing became overbearing. The only thing that sucked were bad recordings yet even there the Ampino wasn't about spotlighting every last oversight. Rather, it made the best of what it was fed. A few hours into happy listening, remember to stay away from the heat sink. Its temps far exceed the comfort zone. What this predicts about the longevity of the output transistors is anyone's guess. To be honest, I'm not quite sure how the Ampino delivers its power in the first place, considering the small mains tranny inside. Many a CD player comes more endowed in that department.

Combine this sound with a more tricked-out enclosure and perhaps snazzier marketing campaign and this puny amp would be destined for major laurels. As is, you'll have to muster the gumption to part with 530 euros for the Abacus Rieder Ampino without incurring an image issue. Should someone find fault with your choice, simply fire it up. A few bars into it, all supremacy smirks will evaporate and the amp cease to be important, to be replaced by musical comments. Now colleague Werner wants to listen to this amp. I reckon he can wait a bit longer.

The Abacus Rieder Ampino is the right amp for you if...
  • You're prepared to say good-bye to conventional expectations about looks and de rigueur circuitry of good-sounding amps
  • You don't give a knat's ass what your friends think - or your friends are exclusively about sonic virtues
  • You plan on doing a lot of listening
  • You don't mind being asked whether you put the amp together yourself
  • You can do without anaconda speaker cables
  • You don't plan on starting a disco
  • You can keep away from the heat sink and park the amp away from kids


  • Abacus Rieder Ampino
  • Power amp with passive attenuator
  • Dimensions: 25×5×2 cm (WxHxD)
  • Trim: Aluminum
  • Weight 2,16kg
  • RMS power: 50W
  • Other: Rieder circuit, direct feedback (zero-ohm approach), no remote
  • Distribution: selected dealers and direct
  • Website
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