Tag Archives: Solid-state power amplifiers

Very sometimes, buying a part is the hardest a part of writing the evaluate. Usually, that’s not the case. Most occasions, one telephone name to the proper individual at a producer or distributor will begin a evaluate in movement, with the part arriving at an agreed-upon time. But with Topping issues haven’t been really easy. Unlike most producers who’re primarily based in nations apart from the United States, Topping has no U.S. distributor. Instead, all Topping merchandise are shipped instantly from China by way of DHL; the corporate has no bodily presence within the U.S. Instead, it depends on Internet retailers corresponding to Amazon and Apos Audio to deal with U.S. gross sales. So, as an alternative of sending out evaluate samples, Topping assigns that activity to its retailers. And whereas my contact at Apos Audio assured me a number of occasions that I used to be “on the checklist” to obtain a Topping LA90, after many emails forwards and backwards over greater than a month, I used to be nonetheless no nearer to getting a unit in my fingers for evaluate. That’s what occurs when there are too few evaluate samples on the market on this planet.

I can depend on one hand the variety of occasions I’ve bought a part earlier than I accomplished writing and delivering a evaluate. The Topping DA90 SE was the primary in a lot of years. I additionally broke down and bought the primary of the 2 Topping LA90s I’ve in my possession. (Why two? Read on.)

It was an impulse buy. I used to be perusing The Music Room’s choices (it’s a web-based retailer which makes a speciality of used and refurbished high-performance audio), and I got here throughout a “like-new” Topping LA90 for $794. Out of curiosity I went to the Apos web site to see what the present new value was. At this level, I used to be stunned when Apos Audio’s price-match AI introduced me with a value of $804 as an alternative of the same old new value of $899. So…I purchased it. Five days later it arrived.

After a few days listening to it in my nearfield system, I contacted Apos Audio to see if Topping provided an business lodging for a second LA90 and its PRE90. They did. But not like corporations that use brick-and-mortar retailers, Topping’s pricing doesn’t enable for the same old 40% or 50% low cost off checklist value. They provided a 15% low cost. I took it. A second LA90 and a PRE90 arrived per week later.

The Question of Reviewer Bias

All my readers are human (I hope), and as people all of us have our private biases. As a reviewer I’m properly conscious of my very own predilections. In the introductory video I did not too long ago for The Absolute Sound’s YouTube channel, I enumerated a number of of them. Another bias I have to acknowledge is that I’ve a special degree of attachment to and affection for parts I personal versus ones which have been loaned for evaluate. It’s the primordial mine versus not-mine, I suppose…and since I do know myself properly sufficient to acknowledge my inclination, I counter it by being much more crucial of parts I personal than of ones which can be loaned for evaluate. Does that degree the enjoying area? Maybe, however be forewarned that I’ll take some additional house to notice all the LA90’s potential shortcomings.

Tech Tour

The Topping LA90 amplifier ranks as distinctive for a number of causes. The first cause it’s particular is that not like most new energy amplifier designs from China and elsewhere, the LA90 is an Old School Class AB linear amp as an alternative of a Class D or different digital variation thereof. Given its extraordinary specs, I inquired in regards to the nature of the design by way of suggestions. The response from Topping’s design workforce (routed via Apos Audio) was that “the suggestions construction is just like [that of] our headphone amplifiers. The S/N determine is obtained via cautious designs of energy provide, resistor decisions, and different fundamentals of design goodness.” Well, okay, then…

The LA90 has extra changes than your run-of-the-mill energy amplifier. You can change the achieve from 9.5dB to 19.5dB by way of a change on the again of the amplifier. This change places a resistor in entrance of the principle amplifier stage. Why would you wish to decrease the achieve? Depending in your preamplifier’s achieve, it’s possible you’ll discover that the decrease achieve places the preamplifier’s output right into a extra linear area.

Even 19.5dB of achieve is on the low facet for an influence amplifier. Most are likely to hover round 26dB, and a few just like the Clones Audio 25P ship 30dB of achieve. When you couple the achieve with the facility output, which relying on whose numbers you employ sits between 50 and 60 watts per channel in stereo into 8 ohms, you will have what most would take into account a lower-power amplifier, particularly when in comparison with the facility amplifier choices from Krell or Boulder.

One solution to get the LA90 as much as a extra respectable energy output is to transform it from a stereo amplifier right into a mono amplifier; each channels could be bridged collectively to make an amplifier able to 180 watts into 8 ohms, in response to producer’s specs. Now you will have two mono energy amplifiers able to driving most medium-sensitivity loudspeakers efficiently.

Inexpensive parts (something below $1000) often come within the equal of a plain brown wrapper—an oblong black or silver-metal undertaking field. The LA90 avoids that pitfall. Its chassis is made of 5 separate CNC-machined aluminum sections (they don’t name it billet aluminum although, like billet, it’s machined slightly than solid), designed to permit for max thermal circulate, in order that as an alternative of a fan or strong high-mass heatsinks, the LA90 makes use of slotted warmth fins that enable for air circulate in a approach that strong heatsinks can’t.

Topping may be very a lot a “numbers store,” by which I imply it prides itself on the excellent specs its merchandise ship. Even its least costly DAC has numbers any high-end producer would envy. The LA90 boasts a complete harmonic distortion and noise (THD+N) of 0.00008% at 20 watts into 4 ohms. Count these zeros…that’s greater than fairly good. Between its THD+N and printed sign to noise (S/N) of 143dB in mono mode, you will have an amplifier that ranks up with the easiest energy amplifier specs, such because the Benchmark ABH-2.

Setup and Ergonomics

As I famous within the technical tour, the LA90 can be utilized a number of other ways. I’ve tried all of them. First, I put in the LA90 in my nearfield laptop desktop system as an built-in amplifier, with the amount management each out and in of the circuit. Used as a stereo amplifier the LA90 had no hassle efficiently driving Audience 1+1 and Falcon LS 3/5A loudspeakers in my reference nearfield system. With extra power-hungry transducers, such because the ATC SC-7 II, the LA90’s 50 watts have been barely lower than what was wanted. But when two LA90 amplifiers have been used on the ATCs in a nearfield setup, there was sufficient present to energy the SC-7 IIs properly.

When used inside arm’s attain as a desktop built-in amplifier, the LA90’s lack of a distant management received’t be an excessive amount of of an inconvenience. But if you wish to use the LA90 as an built-in amplifier in a room-based system, the absence of a distant may provide you with some extra train. (When used as a primary energy amplifier with the amount disabled, the distant was, clearly, not a difficulty.)

When it comes time to modify the LA90 from stereo to monoblock, along with shifting a change you will need to connect a jumper cable between one pair of the amplifier’s speaker outputs. The equipped cable matches tightly, which is nice, however its inflexible strain-relief collars must be fastidiously angled in order that the cable doesn’t both stick up in a approach that partially blocks different cables or all the way down to contact the shelf floor below the amplifier.

Another ergonomic quirk: The LA90 amplifiers in mono mode can get sizzling and are higher off positioned with as a lot house as attainable round them. That’s as a result of they depend on thermal cooling techniques to direct air laterally via their chassis. If you will need to put them facet by facet, I counsel leaving open house round them and elevating them on footers to permit airflow below the amplifiers to cut back inside temperatures.

The exterior energy provide for the LA90 is sort of as heavy because the LA90 itself. It’s a beefy 64 volts and 4 amps. It additionally will get heat throughout operation. Its AC energy cable employs a easy two-prong/figure-8 connection. And whereas you may get some beefy AC cables with that termination, they don’t seem to be as widespread as the same old IEC variety. I used the inventory AC cords, which have been lengthy sufficient to maintain the facility provide away from every other cables and in a well-ventilated spot. I do know that for some people the concept of an exterior PS slightly than an inside one is “cheaping out,” however given the LA90’s thermal design I can’t assist however really feel that placing the facility provide in a bigger chassis with the remainder of the amplifier would have merely elevated the value and decreased the amplifier’s efficiency.

I exploit balanced cables every time attainable, so I had no points with the LA90’s all-balanced enter configuration. But you probably have already invested in some high-quality single-ended RCA cables, you might have to get some RCA-to-XLR or RCA-to-TRS adapters to interface with the LA90.

Even when the amp is in bridged mono mode, you may, if you want, have the amount management within the circuit. While it’s comparatively unusual to see a quantity management on most energy amplifiers bought within the U.S., my expertise with Ali Express-sourced energy amplifiers is that together with a quantity management (often an Alps Blue Velvet) on a primary energy amplifier is widespread in China. If you propose to run an over/below amplifier setup with one LA90 amp set in mono on every tweeter and a much bigger stereo or mono energy amplifier on the midrange/woofers (in a two-way system with separate speaker connections for the tweeter and midrange/woofer), having the ability to alter the LA90’s output would make it straightforward to steadiness the degrees between radically totally different gain-level amplifiers, if wanted.

Sound

My present energy amplifier choices embrace a number of Class A Hood-based designs, a Pass 150.8 class A/B, Texas Instrument chip amps from LSA and Clones Audio, in addition to a number of different Class D amps utilizing Sanyo chips or ICE modules, however nothing in my assortment sounds fairly just like the Topping LA90. It is just essentially the most sonically invisible energy amplifier I’ve heard and comes closest to the perfect of a straight wire with achieve.

Even with my most delicate loudspeakers, a pair of 93dB Omega single-driver prototypes, the Topping’s base noise degree is so imperceptible that even with my ears almost imbedded within the driver I hear no sound in anyway, with no distinction between the sound of the amplifier when turned on or off. Nothing. You’re in all probability pondering: “Big woo! I can get the identical outcome with my XXXX amp and my XXX audio system.” But, belief me, it’s not the identical. The LA90 disappears extra fully than any amplifier I’ve ever heard earlier than. By disappearing, I imply that apparently there may be much less of a way of “amplifier” affecting the sound. Instead, the music is introduced in a approach that looks like a extra direct connection between the supply and my ears.

I’ve a quiet listening room. It measures solely 35dB on my sound-pressure meter in A-weighted mode. In the previous I’ve rejected some very effective gear as a result of it was merely not quiet sufficient for my room. The LA90, even in high-gain mode (which was the way it was used, besides when put in in a nearfield setup), added completely no extra noise, and when coupled to the Schiit Freya S in passive mode, I may flip up the amount controls to most and nonetheless hear completely nothing via the Spatial X-2 loudspeakers (86dB sensitivity) even with my ear an inch away from the tweeter. If it wasn’t for the LA90’s front-panel LED, I wouldn’t have recognized it was turned on!

Ranking essentially the most spectacular features to the LA90’s sound, the primary must be the extra ease in listening. The lack of low-level noise imbues your complete soundstage with a quieter background than I’m accustomed to listening to, even with quiet amplifiers just like the Pass 150.8, which solely produce the slightest hiss (you have to put your ear extraordinarily near the tweeter to listen to it). There have been a number of heretofore-undecipherable throwaway traces within the background of some Billie Eilish’s singles that I take heed to frequently. Through the LA90 I may make out phrases that even via headphones had beforehand been a blur. Was I stunned? You wager.

The second most spectacular sonic attribute was the LA90’s readability all through its frequency vary. Even within the decrease midrange and higher bass, which often have essentially the most points with homogenization, sluggishness, and murkiness, via the LA90 these frequencies had a degree of element and lack of constriction that made music refreshingly straightforward to listen to and decipher.

In his latest evaluate of the Pear Blue Audio Odar turntable, Robert Greene writes: “As it occurs, that is true about audio normally. Low-distortion electronics additionally sound non-aggressive inside a given bandwidth.” I agree. While nonetheless lightning quick, the LA90’s higher frequencies don’t get onerous or brittle even throughout dynamic peaks. I seen this clearly by myself dwell recordings. The violins and brass throughout fff passages of my recording of Mahler’s Third Symphony from Mahlerfest 2013 (co-recorded with Jerry Bruck of Posthorn Recordings) remained musical even throughout massed dynamic peaks. Flutes and piccolos have been candy slightly than piercing.

This Mahler recording additionally demonstrated the extraordinarily correct picture placement inside the soundstage. Not solely was lateral placement exact, however the layering of devices, with the brass barely greater (they have been on risers) and farther again on the stage, was straightforward to listen to. The LA90 does the 3D factor (on recordings that include the spatial info) in addition to any solid-state Class AB amplifier I’ve heard.

Vocals via the LA90 have a exceptional readability coupled with pure heat. The Punch Brothers’ newest launch Hell on Church Street has a tune referred to as “Orphan Annie.” After an acoustic bass introduction that captures the essence of acoustic bass tonality, Chris Thile’s vocals start. Through the LA90/Spatial X-2/JL Audio Fathom f112 system, the sound of his voice had an arrestingly reasonable character. I’ve been round Chris at workshops and jams, so I do know what his voice appears like; this recording, via this method, had a degree of veracity that would, in J. Gordon Holt’s phrases, “produce goosebumps.” Also, in case you pay attention in a quiet room, you may even hear the rustling of clothes because the musicians transfer across the microphone.

Although I exploit a pair of JL Audio f112 subwoofers with the Spatial X-2 loudspeakers, I’ve the system arrange in order that the Spatial X-2s obtain a full-range sign with none crossover truncating their low frequencies. Turning off the JL subs let me hear how the LA90 was supporting the bass. Again, I used to be struck by the readability, particularly within the midbass area, the place the low ranges of synthesizers mixed with guitars and keyboards compete and battle on many pop releases. On Finneas’ “Partners in Crime” from Blood Harmony, the fluttery synth half had a degree of texture and internal element that was straightforward to luxuriate in.

I like Finneas. On his Optimist album, “the 90s” shouldn’t be solely an important tune, but in addition a torture take a look at of how properly a system can reproduce the sound of distortion. At 2:10, what sounds nearly like a sawtooth waveform on the synthesizer begins. Distortion as percussion. As the distortion builds, on some techniques the sound will get more and more foggy and imprecise. Through the LA90 the distortion sounds clear. What? Even as Finneas provides extra layers of distortion, every layer retains its personal identification as an alternative of merging right into a miasmic complete. At 2:53, the distortion halts abruptly, and Finneas solo voice begins, bringing a soothing feeling of calm to the combination.

Competition

Yes, I notice that selecting an influence amplifier isn’t the identical as a horse race. Or is it? At a sure level it does come all the way down to: “What can I get for the way a lot?” For the value of 1 LA90 you may get one Schiit Audio Vidar ($799), which can be a Class AB solid-state amplifier that may be bridged for mono. It has double the facility of the LA90 at 100 watts into 8 ohms, however not fairly nearly as good SNR determine at 115dB down. If you wish to devour extra vitality, have much less energy, worse specs, however get that Class A sonic character, Schiit additionally affords the Aegir ($899), which is a Class A model of the Vidar.

If we take a look at what’s within the value vary of two LA90s ($1798), the competitors will increase. The LSA Warp One amplifier I reviewed in Issue 331 lists for $1495. It has fully totally different topology, being a Texas Instrument switching energy amplifier, however it shares the LA90’s variable-gain characteristic, providing 4 totally different achieve choices by way of DIP switches. The Warp One additionally affords each single-ended RCA and balanced XLR inputs. In phrases of sonic variations, each are exceedingly clear and detailed, however as compared the LA90 delivers a barely hotter higher bass and decrease midrange with some loudspeakers, such because the Falcon LS35/A. Both amps had glorious low-level element and total readability, to the purpose the place the winner in a sonic shoot-out would rely extra on how a selected loudspeaker interacted with every amplifier slightly than variations in intrinsic sonic character.

Although in a totally totally different value class from the LA90, the Pass 150.8 ($7500), has been my main reference amplifier driving the Spatial X-2 loudspeakers. When I first attached two LA90s, I puzzled whether or not the mixture could be in the identical league in total sonic high quality with the Pass Labs amplifier. While the 2 amplifiers had related ranges of element and soundstage capabilities, the Pass had extra grunt and a larger sense of energy in reserve.

Although I not have it to match on to the LA90, the Benchmark ABH-2 ($2999) shared some sonic similarities with the LA90. The ABH-2 was equally quiet and equally good at putting devices precisely within the soundstage’s lateral aircraft, however I don’t suppose the ABH-2 had the identical degree of depth recreation or fairly the identical degree of low-level decision. Through the LA90 I felt listening into the combination was simply simpler and my engagement degree deeper.

Summary

More occasions than even I can keep in mind, I’ve learn audio part critiques which conclude with “I purchased it!” This is often the ultimate coup in most critiques, displaying that the product was so good even the reviewer couldn’t resist it (at a 40% to 50% low cost). That’s not going to occur right here. This type of “massive reveal” has already had its balloon popped within the third paragraph.

For most of my energy amplifier wants, one or two LA90s have been nearly superb. Obviously, I do plan to maintain the pair of LA90 energy amplifiers I already personal, and maybe, as time passes and so they turn out to be extra accessible on the secondary market, I would even decide up one other one or two, simply because….

If you will have mid- to high-efficiency loudspeakers that you just love, it’s possible you’ll discover the LA90 to be a great energy or built-in amplifier to your system, too. I can simply see a single LA90 because the “summer season amp” in high-efficiency horn techniques. I’d not advocate that house owners of 2-ohm Apogee Scintillas or Theil CS3.5s, or you probably have a big room with solely reasonably environment friendly audio system, run out and purchase a pair. Some loudspeakers merely want extra energy than even two LA90s can provide.

But until you will have a good friend who has already bought an LA90, your probabilities of listening to one or attempting one out before you purchase are just about nil. If you might be intrigued by the LA90’s potential, you’re going to must take a leap of religion (with a 45-day return window from Apos or 30-day from Amazon) and purchase earlier than you attempt, similar to I did. So, whereas I’d often end a evaluate by recommending you hear a product for your self, that’s going to be troublesome with the LA90. However, in case you’re feeling fortunate (just like the signature dialog from the movie The Mask), I encourage you to take a leap of religion and provides the LA90 a attempt. I critically doubt you’ll be disenchanted by its capabilities or efficiency.

Specs & Pricing

Type: Solid-state Class AB amplifier
Output energy: 50Wpc into 8 ohms stereo, 180W into 8 ohms mono
Inputs: Three XLR/TRA inputs
Output impedance: <3 ohms
Dimensions: 20.5 x 22 x 9cm
Weight: 2.7 kg
Price: $899

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