Been into stereo/audio for 40+ years, all with solid state amps. About 20 years ago became fascinated with the minimalist/purist approach and tried to warm up to the SET scene. But being a “speaker guy” couldn’t find an affordable high efficiency speaker that didn’t lack bass and/or exhibited some form of colorations. 12 years ago settled on “the” speakers (Brine Acoustics M18-F200, Fostex F-200 full range driver, 90 dB/w/m, 8 ohms, 25 – 20,000 Hz with Bud Purvine’s EnABL driver treatments). The EnABL’d Fostex F-200 has been called one of the greatest extended range drivers in the world and when paired to the transmission line cabinets have a deep/warm sound unlike other single driver speakers.
Had a 7 wpc tripath at the time the M18-F200 came home (sounded amazingly decent for being so small). Up’d the ante to Channel Island Audio 40 wpc chip based mono-blocks with passive pre-amp, then stepped attenuators (still into the purist concept) that made very satisfying sound. Then stepped up functionally (sound quality slightly better) to a Jaton Operetta RC200S pre-amp ($1500 MSRP, neutral sound, high content value, well built) and Channel Island Audio D-100 mono-blocks ($1600/pair MSRP, modified Hypex digital).
But the time spent with the little tube amps continued to haunt me with their smooth, palpable, and organic sound. I had always held back from the “enlightened path” because of concerns over worries of the sound changing with tube aging, going nuts with tube rolling choices, and the tube associated inconveniences (can’t leave on, cost/hassle of replacement). On the other hand with the basement man-cave located in the great white north, tube heat was welcomed. So with relatively little research (for me) the trigger was pulled on this ($3,400 MSRP) amp.
• A thoroughly modern, flexible, and high quality tube amp (rated 2014 Stereophile Class “A”) equipped with (6) 12AU7 (4 acting as a cascade voltage amplifier & 2 as phase splitters) and (4) output tubes
• Soft start circuit, AC Offset Killer, Adaptive Auto-Bias, bad tube indicators, power transformer protection, output transformer protection, HT bypass, dedicated line level mono subwoofer output, and full function remote
• 4 & 8 ohm outputs, EL34/KT88 bias switch, ultralinear/triode option, many possible tube options, (5) pairs of inputs (phono pre-amp optional with reportedly a better one coming)
• Various output tube options include EL34, 6550, KT88, and KT120
• Hand assembled, point to point signal wiring, premium parts throughout, weighs a hefty 66 pounds and apparently well built
Note that the protection circuits are not in the signal path and that they can be most helpful to tube newbies. The Adaptive Auto-Bias actually helps extend tube life, minimizes tube voicing throughout their lifetime, and works so well you can reportedly use a simultaneous mix of output tube types.
Source is my current system weakness: a 2012 iMac, using iTunes connected via a cheap 35 feet optical cable to a Behringer DEQ2496 (that has a DAC section modded by Scott Endler). The rest of the signal cabling is custom ordered, also from Endler. Room is a Cardas “Golden Cuboid” (8 ft x 13 ft x 21 ft); set-up is also by Cardas (68 inch equilateral triangle, semi-near-field); concrete slab on grade, walls/ceiling envelope insulated wooden framing; insulated/sealed fiberglass exterior door; no metal ductwork; and dedicated audio circuits/grounding.
Music is mostly classical, swing/50’s/soft jazz genres, and a variety of old fart mellow stuff with occasional rock normally at “more mature” listening levels.
So (finally) how does it sound (after several weeks and hundreds of hours) in my system/room to these old ears?
• No hum or tube rush, dead quiet
• 4 ohm vs. 8 ohm & EL34/KT88 bias (provide little difference), very slightly prefer triode to ultralinear (Auto Bias may be limiting the differences)
• Highly resolving (detail and image specificity) of liquid satin, yet even older CD era and otherwise less refined recordings sound better (isn’t that ideal?)
• Compared to the Jaton/CIA – denser sound/images, improved detail, rich musical presentation, more dynamic, looser bass makes up for some of the baffle step loss, cymbals exhibit splash, highs are less steely
• Output tubes tried (all cryogenically treated, in order of preference): 6550, KT88, EL34, and finally way out in last place the KT120 (which was barely an improvement over the Jaton/CIA)
Conclusion: With the right tubes the PrimaLuna Dialogue Premium Integrated Amp is definitely a keeper, but I’ll also hold on to the Jaton/CIA combination that is good enough for casual/far-field listening, as a back-up, and worth more to keep than sell.