VAC Sigma 170i Integrated Amplifier Page 2

With feeds from various open-reel tape decks, I wallowed in the assorted tracks from a compilation aimed at philistines such as myself. Tchaikovsky's Greatest Hits [Mercury MEF9126] is a testament to that label because even at 3¾ips, the sound was gorgeous. Though there are no artists' credits (and nor was it from the legendary Living Presence series), via the 170i the delivery was lush and cosseting even when compared to other amps in triode mode. When my wife happened to pass by, she made a remark about how she wished her flute playing sounded as fine.

Strings were extended, detailed and fast as lightning, and also utterly free of any 'screech' or unwanted edginess. But probably the most telling element was the sense of space and air, which remained from speaker to speaker, including the juxtaposition of changing from the big Wilsons to wee Tannoy Autograph Minis.

921vac.remMoving to a more highly-pedigreed tape, in that it was twice the speed and not anonymous, the grandeur of Handel's Messiah, with Stokowski conducting the London Symphony Orchestra and Chorus [London LCL75014], rattled even this non-believer. The vocal elements were as perfectly defined as I have heard, while the recreation of a concert hall defied the constraints of my listening room.

Blessed Relief
A switch to vinyl raised a thorny question, which is a subset of the integrated-vs-separates debate, and I would be remiss not to address it. The sum of £1500 will pay for any one of a number of astounding standalone valve phono stages, most with a far greater choice of settings, eg, models from Pro-Ject, Icon Audio, EAR-Yoshino, EAT, and far too many others to list. And who can even count the exceptional solid-state phono stages, from Rega, Thorens, MoFi, ad infinitum?

And yet… the entire matter of justifying an integrated phono section, encompassing convenience/space-saving/one less set of cables, as well as 100% compatibility cannot be ignored. It is precisely the same rationale for buying an integrated amp per se. Luckily, VAC's optional phono stage is exceptional.

I didn't expect anything less from the 47kohm MM stage, which was perfectly accommodating of my Ortofon 2M Red [HFN Oct '08] cartridge. But what proved a blessed relief was how the three MC settings handled the TechDAS TDC01 Ti [HFN Sep '14], Kiseki Blue [HFN Jul '18], Denon DL103GW and EAT Jo No5 [HFN Dec '18] pick-ups.

Real Deal
My go-to bass tester, Tony Joe White's Homemade Ice Cream [Analogue Productions APP-2708-45], proved revelatory in the truest sense of the word, in that it exposed something previously unseen (or heard). I knew the Sasha DAWs provided prodigious bass, but the Sigma 170i mated so well with it that from the opening cut, 'Saturday Night, In Grove, Louisiana', the experience took on a new dimension.


Inside the point-to-point wired Sigma 170i showing L/R audio boards [top right] with low-ESR bypass capacitors, optional phono PCB [top left] with Lundahl transformers used for MC input and balanced line input [bottom left]

Those of you who read liner notes will appreciate what it means when a band includes the cream of Nashville: the late Reggie Young on guitar, David Briggs providing piano and organ, Norbert Putnam on bass and Kenny Malone on drums. They're among the reasons why Chad Kassem chose this LP for Acoustic Sounds' deluxe 45rpm treatment. Any of you who harbour the notion that no tube amp can provide lowest octave solidity like a transistor amp need to hear this via VAC's 170i.

Whether it was the bass guitar lines or the percussion work, the foundation this amplifier created was one of weight, presence and almost-scary realism. Better still was the handling of White's distinctive, rich, swampy vocals.

This prowess, however, wasn't dependent on the superior pressing at higher speed. With the 2014 reissue of Etta James' sublime Tell Mama on Bear Family [BAF108026], certainly not known as a label of the audiophile tendency, the otherwise average recording did not hold back one iota of James' peerless, powerful vocals on this milestone LP.

You want emotion? Here Etta James rips out your heart, and the Sigma 170i ensured that every dynamic moment was treated with respect. Damn, this is a fine amp.

Hi-Fi News Verdict
Not wishing to revive the separates-vs-integrated debate, I'm loath to declare VAC's Sigma 170i an alternative to its far beefier pre/power kin. Yet it laughed at everything I could throw at it, delivering via Sasha DAWs the kind of levels and soundstage which did justice to the scale of both 'big band' and classical orchestras. It's a love letter to the much-revered KT88, and it left me stunned.

Valve Amplification Company, Inc.
Florida, USA
Supplied by: Signature Audio Systems, UK
07738 007776