Exploring the air waves on triodes

I am in one of those rare Hifi hobby states of being that's completely satisfied with the performance of my rig. The combination -- of Avantgarde Duo loudspeakers, Fi 2A3 amplifiers, Tom Evans Design preamplifier, Audio Logic 2400 DAC, Meridian 508.20 CD player as a transport, all tied together with Nirvana cables -- captures the combination of sonic and emotive traits I crave. In this state of magdalen contentment, I've been on a quest of exploring new music for its own sake, enjoying the pure adventure on this -- usually under heavy construction -- audiophile avenue of bliss.

My voyage into musical rather than hardware discoveries got me thinking about tuners. They seem to be an ideal way of exploring new music. After thus concluding that it would be a generally cool and phat thing to explore the world of tuners, I contacted the nice folks at Magnum Dynalab for one of their new Triode Series FM tuners, only to receive an immediate heads-up from prez Larry Zurowski on the entry-level $1,595 MD-90t which was inspired by Magnum Dynalab's $5,850 MD-108 tube-hybrid flagship.

There are a number of appearance and performance options whereby to trick the MD-90t out - and no, the guitar's not one of 'em. The standard faceplate is black but a spare $100 turns it silver or gold anodized with contrasting lettering. Internal Kimber silver wiring is said to improve detail and high frequency extension for $175 while infrared remote adds $395, balanced audio outputs $100. Magnum Dynalab also had sent along their indoor/outdoor omni-directional AM/FM antenna to displace my usual secretary for reception duties. This $99 vertical half-wave design made of stainless steel is a little longer than a dreadnaught guitar and accompanied the standard, zero-options MD-90tduring the review process.

To the uninitiated like me, the MD-90t can look at first somewhat intimidating. There are three different metered displays, four different toggle switches, a rotary tuning knob, and a frequency LED display. So after unpacking the unit, I set it aside to study up on the manual before firing up my luxo radio loaner.

The manual was written in such a way as to suggest that the Magnum Dynalab folks actually care that one got off - to a good start with their baby, that is. The toggle switch to the far right turned on the AC power to cause all meters, frequency display and the stereo indicator to light up for a rather beautiful effect during black-out listening.

This tasty amber glow wasn't unlike a vacuum tube or candlelight, with the stereo indicator emitting a twinkly blue.

On the fascia's left side, three vertically aligned toggles switch between stereo/mono to clean up noisy stereo transmissions; intermediate frequency; and mute to suppress weak signals during station scanning. The stereo/mono option worked really well. Tuning into a very noisy station, going to mono created perfect background blackness. A blue indicator below the signal meter lights up for stereo mode and extinguishes in mono. The IF intermediate frequency selector toggles between bandwidth 1 and 2 settings (BW1/BW2), the latter reducing bandwidth to 'narrow' to eliminate adjacent-channel interference. The function proved useful by eliminating weak stations during a frequency up/down scanning of the available airwave menu.

The left of the meter trio shows multi-path interference, allowing fine-tuning of antenna orientation and position to ideally read 'zero'. I just plugged the antenna in, leaned it up against the wall and enjoyed perfect reception without even trying. A reception-challenged area would truly demonstrate this feature's usefulness, but as it stood, I could remain oblivious to multi-path needle deflections. The middle center-tune meter allows precise calibration of a station's strongest center frequency while the right window displays signal strength. Not so complicated after all. In fact, it turned out that the MD-90t was far easier to use than appearance would have suggested. After I dialed in the station I wanted, there really wasn't anything else to do but enjoy the tunes.

My impression of the MD-90t's build quality was altogether positive, the solid and attractive appearance suggesting a lot of value for its $1.6K list price. However, casual window shopping wouldn't suggest any tubes inside the chassis safe for the tube emblem 'round back. A tinted see-through top cover like the Tom Evans Design Vibe (no tubes) or a vented top like the Audio Logic DAC (tubes) would be swell so you could peek inside to spot those glowing tubes - tube crazies like that sort of teasing. The three-stage radio frequency tuner front-end is a Magnum Dynalab exclusive and designed/ manufactured in-house, with the manual stating that they're the only company in the world to build their own as "no other manufacturer can produce one that meets our exacting specifications". Other technical details are the Philips 6922 tube in a zero feedback amplification stage designed by Zdenko Zivkovic; Solen polypropylene capacitors in the signal path; and a toroidal power transformer.

So how does the MD-90t sound? Very good. In fact, I was rather astonished at how good the MD-90t performed in my Duo-Fi-Vibe-Nirvana system. Case in point: John April -- of local bluegrass guitar, mandolin, and banjo fame -- stopped by on a Saturday afternoon for a quick visit. I had NWPR's Inland Folk program running, playing a nice number with Tony Rice and Doc Watson on guitars. John grabbed my flat-pickin' Gibson Advanced Jumbo guitar off its stand and began to jam along with Tony and Doc. After the tune ended, John wanted to know which CD that had been. "It's not a CD, it's an FM tuner from Magnum Dynalab I am reviewing for 6moons", I retorted glibly. "Wow!" countered John. And "Wow!" was right. The sound quality of Tony and Doc through the MD-90t wasn't that far off John's live sound playing the Gibson AJ. Granted, the FM broadcast was a little softer, less percussive, less present than the real thing, but not leagues apart. More importantly, it was musically engaging to the extent that it made John want to grab my guitar off the stand and play along. Now that, my friends, is high praise!

It was also very easy to hear the difference between digital and analog broadcast sources. You could easily tell if a station was playing vinyl or CD if you listened for it. I guess I was surprised by this. I didn't really expect this level of resolution from FM signal sources. Could it be that with FM -- as with RedBook digital -- there's a lot more musical data embedded in the raw medium than anyone would have reckoned? It appears that the music is just waiting there, hidden, to be revealed by a high quality source component such as the MD-90t.

The overall character of the MD-90t was neutral in the most complimentary sense of that term - neither dark nor bright. The nature of a given broadcast recording or other associated equipment in the signal chain had considerably more effect than any fingerprint of character from the tuner itself. In my Duo-Fi-Vibe-Nirvana system, you can hear everything that makes high-sensitivity and single-ended triodes so popular: Dynamics, communicative directness, scads of detail and natural tonal colors. In a second system around the Harbeth Monitor 30 loudspeakers and Naim NAC 112/ NAP 150 entry-level separates, the MD-90t let all of their traits emerge: Outstanding communication of musical intent; melodic & rhythm prowess; and the incredible articulation of timing accents that give music life on a note-by-note basis.

The perspective of the MD-90t was no easier to pin down than its character. It again seemed largely dependant on the recording and other associated equipment, rather than any intrinsic trait of the MD-90t itself. If the recording was close mic'd to position the listener in intimate proximity, that's how the MD-90t would depict it. If a recording was encoded with a mid- or rear-hall perspective, that's what the MD-90t would parlay.

With the MD-90t in the Duo-Fi-Vibe-Nirvana system, the sound emanated largely from behind the plane of the Duos, yet with certain information present in front of the plane as well, particularly when moving outside the speakers' location towards the sidewalls. On some familiar recordings, I have even heard distinct images coming from positions as much as four feet to the sides of the Duos, giving at times an almost holographic wrap-around effect, with sound breaking down the sidewalls like ocean waves. This sonic phenomenon must be revealing out-of-phase artifacts present on certain recordings, perhaps due to the microphone and mixing style during the mastering and production process, but it's quite astonishing and entertaining when heard. In today's context, it must be considered quite an accomplishment that the MD-90t could reproduce that effect from FM when called upon by the transmitted programme material.

The amount of soundstaging information contained within FM signal -- and as captured by this triode tuner -- was considerable. There was even a good sense of soundstage depth extending back towards the rear wall of the recording venue. This became particularly evident on the classical music broadcast from the Washington State University by Northwest Public Radio (89.1), a station I've been listening to and enjoying a lot of late. Stage height too was good, with instrument and vocalist sizing proportional to the recording perspective. This clearly avoided that "mini-ships on mini-seas" effect which some equipment is guilty of. If the rest of your system can reproduce correct sizing information, the MD-90t will deliver the goods.