This review page is supported in part by the sponsors whose ad banners are displayed below
This review first appeared in the September 2009 issue of hifi & stereo magazine You can also read this review of the SAC Beta and Igel 60 in its original German version. We translated it through a syndication arrangement with our German colleagues. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of orSAC. - Ed.

Reviewer: Ralph Werner
Financial Interests: click here
Sources: Analog – deck - Acoustic Solid MPX; tone arm - Phonotools Vivid-Two, SME M2 12-inch; pickup - Denon DL-103, Ortofon MC Rondo Bronce, Shelter 201, Zu Audio DL-103, The Cartridge  Music Maker III; digital - CD-Player -  audiolab 8000CD, HiFiAkademie cdPlayer; Computer & Co: Logitech Squeezebox, Readynas Duo NAS-Serve, HP Notebook; D/A converter - Benchmark DAC1 USB
Amplification: Phono - Aqvox 2 CI MKII; preamp - Octave HP 300 MK2; power amp - Electrocompaniet AW 180, SAC il piccolo; integrated - LUA 4040 C, Myryad MXI 2080
Speakers: ASI Tango R, DeVore Fidelity Nines, Zu Essence
Cables: Various
Stands and supports: Creactiv, Taoc, Liedtke Metalldesign Stand, Shale Audio Base
Review Component Retail: €698 Beta, €1,499/pr Igel 60

It wasn’t a matter of if but when I’d get to SAC’s most popular pre/power combo of Beta preamp and Igel 60 monos. Ever since my enthusiastic review of their Il Piccolo monos (€4.800/pr), I’d been keen on learning how the rather cheaper el spikies would do. A pair of hedgehogs weighs in at onefive, just shy of twotwo with the matching preamp. This deposits us at a rather more cheerful address considering the times. Both Beta and Igels were recently made over. A few weeks ago, SAC’s designer Herr Fuchs began to load a "completely new PCB layout" into a chassis whose looks haven’t changed for a quarter century. That’s how long the hedgehog has ruled - clearly no one-day wonder.

Latter-day shenanigans of Mk1, 2 or 3 silk screening on the face plate weren’t on the menu either. It’d look a bit silly if one eventually got to 6, 7 or 8. Plus, altering cosmetics after such a long rein would approach sacrilege. Why bother? The cuteness factor here is due to compact dimensions of 170 x 82 x 205mm which bypass trophy hunters, poseurs and diva-esque statements. The Beta preamp is similarly sized. This nearly allows placement of all three components cheek to cheek on a single shelf (sadly not quite). But cuteness isn’t the only leitmotif. The trademark bristling crown on the monos, a U-shaped heat sink covering top and sides, didn’t merely godfather the hedgehog nickname which stuck. It also expresses the form-follows-function mandate to a ‘t’. Heat is supposed to vent outside. Why hide the heat sinks inside?

Opinion will diverge whether the Beta preamp’s source selector is the last word in modern chic. That bugger looks and turns like a black-painted Fischer Technik building block. It clicks into position so clunkily as only antique light turn switches in ancient houses still do. That nearly makes it cool again and had me quite deflated when in the same breath, Herr Fuchs divulged that this gnarly beast only triggers sealed relays of the most state-of-the-art modernity. Veering inside, the Igel 60 monos are class A/B push-pull jobs running bipolar transistors exclusively. That includes the output buffer which delivers current to the speaker terminals. One complementary pair each does the heavy lifting per channel. When asked at what rating the transition from class A to B occurs, Fuchs outright refused to "add further nonsense to complete and utter nonsense" and continued with explanations on complex speaker loads and their interactions with amplifiers. Curmudgeonly charm at its best. Ditto the not entirely serious advice to write about "current feedback" instead which, contrary to regular voltage feedback, has less effect on bandwidth versus circuit gain. Since SAC favors wide bandwidth—ca. 200kHz for both Igel and Beta which in conjunction with rise times arrives at the non-technical 'speed' of a circuit—the choice of feedback had to support that design goal.

Feedback is applied both locally and globally. The former serves smooth transitions between gain stages (three for the Igel, two for the Beta), the latter linearizes the gain under all conditions. Eschewing global feedback altogether as is currently popular in high-end audio risks a floating gain factor according to Fuchs. If this fluctuates with frequency, you’ve got a problem.

This subject continues to polarize the hifi scene and quite contrary to popular trends, SAC preaches the more-is-merrier gospel to the tune of 80 to 100dB of NFB depending on frequency. Negative feedback doesn’t merely stabilize circuits, it reduces overall distortion and lowers output impedance. The Igel specifies the latter as 1mOhm.

With a nominal 8-ohm speaker, this creates a damping factor of 8.000, a very high value in accordance with SAC’s belief in speaker control. They seem nearly antagonistic in fact over the output relay which gobbles up half a milliohm by itself. The bigger Il Piccolo mono does away with such a relay to increase its damping factor to 20.000 but also makes funny noises during power on and down. Not so the Igel. Its relay causes a mechanical click but nothing transmits through the loudspeakers. Herr Fuchs is happy about progress in parts quality. Not so long ago, the contact resistance of typical relays was 10 times higher than what he uses today.

Performance extends to the choice of capacitors and output transistors. To avoid misunderstandings, the Igel’s signal path is free of all caps and DC-coupled input to output. Output protection clamps down on shorts, thermal runaway and subsonic frequencies. The output transistors require further words, too. The makeover of the Igel did not raise its power output. That remains at 80/120/150 watts into 8/4/2 ohms. Alas, the new transistors do sport a greater surface area to conduct heat away more efficiently.

This creates less thermal fluctuations during temporary peaks for increased thermal linearity and sonic dividends. Fuchs suggested parallels to increased headroom with identical PS rating. (The close-up of a bipolar transistor is from Wikipedia). Though its output rating didn’t scale up, current delivery increased and the Igel now manages 15 amperes even at higher frequencies where the earlier version was limited. The biggest sonic advance however comes from a new precision op amp which controls the global feedback loop. Because "designers have to keep certain secrets secret", its type and operational details aren’t divulged. Let’s move to the back panel and nothing special in particular. An RCA acts as input, so-so terminals become the outputs. XLR is off the books and power cord jockeys are out of luck with the captive mains cable. Ditto for the Beta preamp whose cord doesn’t plug into the wall socket however but an external power supply, a move that’s intended to keep possible stray fields of the power transformer at arm’s length from critical low-level signal junctions. The umbilical allows for a meter distance to nip any interactions squarely in the bud. The PSU contains a 30VA tranny and a total of 6.600uF capacitance. Its moniker Standard points at a more upscale option, a bigger regulated affair which squeezes your wallet to the tune of €998.