LSA VT-70 integrated amplifier Page 2

Like most tube amps, the LSA looks best without its protective cage, especially at night. There's something cool and comforting about seeing those fiery filaments out in the open. Besides, tube life may be extended when air can move freely around the hot glass. It's possible.

Cage or no cage, LSA warns that pets and tube amplifiers are as dicey a combination as gasoline and a match: "The glass envelope of the tube is warm enough to burn your inquiring pet's nose, and possibly cause a tube to explode," says the manual. That's a different kind of Exploding Kittens. But wait, there's more: "The warmth from the amplifier can encourage your pet to urinate, causing damage that is not covered under warranty, and [it] could electrocute your pet." If you've told Boots once, you've told her a thousand times: no peeing on the audio gear!


Lend me your ears
After letting the amp cook for about 150 hours by playing white noise through it at night, I started my serious listening with Taj Mahal's sixth studio album, 1973's Oooh So Good 'n Blues (16/44.1 MQA, Columbia/Tidal; footnote 3). It's a sonic treat, almost as good as Muddy Waters's vaunted Folk Singer, my (and plenty of other people's) reference for audiophile-grade blues recordings.

I confess that an admiring F-bomb escaped my lips when the music started: The VT-70 produced possibly the best-reproduced male voice I've ever heard in my listening room. The vocals and handclaps on "Railroad Bill" sounded borderline holographic. In short, the LSA hit it out of the park.

Next, I called up Taj Mahal's eponymous 1968 debut album (24/96 FLAC, Columbia/Qobuz). It sounded sharp and aggressive. To be sure, that's the recording, not the amp. I'm not usually a fan of those kinds of sonics, but my favorite living bluesman tackles songs like "Leaving Trunk" with so much gusto and energy that it would be pointless—no, wrong—to wish for a liquid, smooth presentation instead. The VT-70 reproduced what it was given, adding only a slight caramelish quality. Tubes will do that. I found the LSA less euphonic and more controlled in that regard than most sub-$3000 tube amps I've heard.


I also liked the finesse and delicateness that the VT-70 brought, for example, to Lana Del Rey's "Dark but Just a Game," from the album Chemtrails Over the Country Club (24/48 Polydor/Qobuz); the nontonal sounds she makes—effs and esses and tees—came through without edginess or excess sibilance. In the crooned line, "No rose left on the vines," every t and v and s was there in high definition, smooth but not smoothed over. "Unexaggerated," I wrote in my notes. The same quality came to the fore in the minimalist xylophone on Oren Lavie's "Her Morning Elegance," from The Opposite Side of the Sea (16/44.1, Tuition/Qobuz), its bell-like ringing exceptionally rich and textured.

Next, to check the VT-70's low-end performance, I played "Redline" (24/96, Because/Qobuz), from Live Vol.1 by Parcels, a dance track that sounds as if Kraftwerk and Daft Punk made a baby. The chunky synthesizer bass was satisfying and persuasive. With the VT-70, the lower registers tended toward the Rubenesque—not the angular—but it still delivered not just weight, but speed.

In my seriously positive review of the $5600 PrimaLuna EVO 400 integrated tube amplifier in June 2022, I observed that "with reggae and dub, I sometimes heard less control in the bass than I do with my solid state gear. Some overhang was present, with the deepest bass notes not as apt to stop on a dime."

Whatever Huang Jia Nuo did with his design, it's working. I think I might prefer the VT-70's bass over that of the EVO 400. It not only has real heft; it sounds nimble at the same time—over and over, as I confirmed with Yello's "La Habanera" from Yello 40 Years (16/44.1, Polydor/Tidal) and Boz Scaggs's "Thanks to You," from Dig (16/44.1, Virgin/Qobuz).


The LSA amp, while always pleasant to listen to, fell short of perfection. (What product is perfect?) After listening for a while, I became aware, first, of a reediness in the midband. Bruce Cockburn's vocal on "Incandescent Blue" from Dancing in the Dragon's Jaws (16/44.1, Millennium/Qobuz) didn't sound quite as fleshy as it had on the EVO 400; I got less of a sense of body organs doing their thing. What's more, the LSA amp gave nasal-sounding performers no room to hide, exaggerating that quality just a touch: Fans of Tom Petty and Bob Dylan might find a different amp more to their liking. This characteristic may depend on the impedance curves of the loudspeaker you're using—often the case with traditional high-output-impedance tube-amp designs—so it could be unpredictable. I'll be interested to see what JA's measurements show.

Another, perhaps related, limitation showed up primarily in some jazz recordings. Through the VT-70, trumpeters Miles Davis, Eric Truffaz, and Avishai Cohen sounded fantastically full-toned and beguiling, but the spell sometimes lapsed when other horns entered to play a massed part. I heard some shrillness to horns blowing simultaneously and, more rarely, to passages when several instruments were playing on complex, multitracked rock recordings (Zappa, Thaikkudam Bridge, XTC) played at higher volumes.

On the plus side, the width of the soundstage was stellar pretty much across the board.


By the time I played Debashish Bhattacharya's Slide-Guitar Ragas from Dusk Till Dawn (16/44.1, Riverboat/Tidal), I'd connected a pair of Monitor Audio Bronze 100 standmounts ($725/pair) and was rewarded with music that excelled in energy and accuracy of scale. Compared to my reference speakers—Tekton Moabs and MartinLogan Odysseys—nothing was diminished in size, and the stepdown in sonics was surprisingly slight. The stick hitting the rim of the snare on Marc Cohn's "Walking in Memphis" on his eponymous first album (16/44.1, Atlantic/Qobuz) had a bit too much snap or edge. But after I used Roon to EQ the Bronze 100s three or four decibels down in the 2.5–4kHz band, where they're a little hot, I got them to sound to my considerable liking.


The EQ'd marriage of the LSA amp and the Monitor Audio speakers was happy enough that I listened with great satisfaction over the next several days. Excitement was always part of the duo's performance, from Dexter Gordon's smokey, sonorous "Three O'Clock in the Morning" from Go (16/44.1, Blue Note/Tidal) to Childish Gambino's "This Is America" (single, 16/44.1, Sony/Qobuz), a track whose backing singers seemed to spread the full 14' across my front wall. An on-the-nose rendering of The Birthday Party's roaring, raucous "Zoo-Music-Girl," from Prayers on Fire (16/44.1, 4AD/Tidal), demonstrated that the VT-70 paired with well-matched speakers can rock with the best of 'em.

Only once did the amp give me trouble, and it was a tube issue. About 10 weeks into my almost-nightly evaluations, the sound suddenly went to pot. On both headphones and speakers, there was now a graininess to the midrange, a speckled quality: Picture a popcorn ceiling. When I asked the LSA team for advice, they contacted the facility in China, whose chief engineer theorized that the 12AX7 tube must have gone bad. Two days later, I received and installed a replacement, and all was well again. Such service is not limited to audio reviewers: Included in the modest price is a six-month warranty on tubes.


After decades of negligible inflation, we're now in an era of eye-popping price hikes. However, if we ac-cent-tchu-ate the positive, we see that the world of home hi-fi remains rife with serious bargains. Examples: Topping offers a truly sterling balanced preamplifier, the Pre90, for a buck less than $600. If you're shopping for bookshelf speakers, these Monitor Audio Bronze 100s, the JBL L52s, and the LSA Signature 50s, all of which I own or have tried in my home, provide yuge amounts of high-performance fun for under a thousand bucks. Class honors go to the WiiM Mini, a hockey-puck–sized streamer with gapless, bit-perfect playback whose price recently dipped from $99 to $84. At this rate, you'll find one free in your next box of Cap'n Crunch.

The VT-70 falls into the same category. You may not find one in a box of cereal, but it provides superlative quality for cheapskates, penny-pinchers, and the merely unwasteful. For $1299 ($100 more once the intro price expires), you've got yourself a su-weet-sounding tube amplifier that has no glaring faults. As long as you couple it with reasonably efficient speakers, it can hold its own against upmarket competitors costing several times as much.

Affordable, delectable, and just about unflappable, the LSA VT-70 is a tonic in inflation-blighted times

Footnote 3: Unless you count the Sounder soundtrack, in which case it's his seventh—unless you don't count Recycling the Blues & Other Related Stuff, which includes both live and studio tracks, in which case Oooh So Good 'n Blues is, once again, his sixth.—Jim Austin
LSA/Underwood HiFi
(770) 667-5633

Jack L's picture


Don't hold yr breath on Chinese-made tubes. Lower cost shorter life-span. No miracles !

Such 6-month short short warranty should have already hinted the consumers what would happen sooner or later.

FYI, the 50-plus-year-young Telefunken ECC83s & then-brand-new made-in-Geat-Brtain Mullard ECC82s used in my phono-preamp for some 7 years, operating quite many hours week-in week-out. They still make me good classical music - nooo problem.

Brandnames speak !

Listening is believing

Jack L

Bill Leebens's picture

Ir's worth noting that a great many audio products are only warranted for 90 days until the warranty is extended when the product is registered with the manufacturer.Those warranty terms don't apply to tubes included with a product---
that six month warranty on tubes is the de facto standard---Chinese, Czech, Russian, whatever. The longest warranty I know of for tubes included in a product is one year, and that was only for the small signal tubes. I've seen power output tubes with as little as 90 day warranty coverage.

Jack L's picture


Really? So please name a few brandname audio products in the marketplace today only provide "90 days" warranty.

I am all ears

Jack L

Jack L's picture


Guys, No politics in this open venue please.

As posted in Stereophile forums since day one a few years back, I am on 'quality" only.

While we are still on this tube amp, suppose you were the owner of this amp, just arrived & put on test run - it broke down in no time!
What woud you feel ? You would still love its design/quality control ?????

It could be built in the Silicon Valley, CA, or the Brazilian rain forests or whatever. It "happened" to be made-in-China ! This unfortunately reflects on the "ethnics" issue as seen by some politically knowledgeable readers here.

In fact, I fixed a few "high-end" tube power amps made-in-China, using bigboy tubes, e.g. 300B & 2A3 just within a few years & surely I know how good were those made-in-China were. Even after upgrading it with expensive audiophile-grade caps, interwiring etc etc as requested by their ownes, the upgraded sound quality did not impress me at all vs tube amps built in Japan/USA which I auditioned before.

I quote basing facts being an electrical engineering guy.

Listening is believing

Jack L

johnnythunder1's picture

Hungarian music (Bartok string quartets) on my French, Canadian, German, Italian and British system.

Jack L's picture


I love Chinese ethnic cuisines bigtime, not those cheapie 'alien' chinese food in foodcourt takeawys or in foodcups !! Like tubes, money talks !!!

Yes, I pretty like Brahms' music, particularly his Violin Concerto in D Major. Soooo romantic !!

His Hungarian Dance No. 5 is also my favourite, not the other Dances though.

Listenig is believing

Jack L

JaredBeebe's picture

I noticed the Crazy Eddie reference or Easter Egg, does this reference "The Mote in God's Eye" by Larry Niven and Jerry Pournelle?