Topping Pre90 line preamplifier

There has not been a conventional preamplifier in my main audio system for quite a while, because no multichannel preamp is available that's of high enough quality. Instead, I use the high-precision digital volume controls in my players and DACs and choose sources with a relay-based multichannel analog switch. Plus, I tell myself that no preamp can be more accurate and transparent than no preamp.

However, I recently installed Dirac Live 3, which effectively reduces the available system gain by almost 20dB! In my salad days, I would have designed and built a balanced driver with gain for each channel; today, I require an off-the-shelf solution. After weeks of research, I found one: the Topping Pre90 ($599)

I didn't really want a preamp in the system; I just needed more muscle. My DACs, which have a specified maximum output of 3V, were being pushed to the limit. The Pre90 was enticing me with 16dB of maximum gain and potential output of up to 50V peak-to-peak.

"I see [a preamp] as a high-quality volume control plus input selector," said Topping's John Yang. "The main goal is to achieve [the] lowest noise and distortion possible. Digital volume controls in DACs are in the digital domain, before the D-to-A conversion, so the noise of the DAC remains the same after attenuation. So, you always lose S/N ratio this way, regardless of the precision of the digital volume control. An analog volume control conserves SNR, because it attenuates the noise as well as the signal from upstream." However, a careful design is required, he noted, to avoid adding more noise. "The noise needs to be low at all volume settings. Low-impedance internal circuitry allows this low-noise performance."

A high-quality preamp can serve other functions, too, and it's precisely what I'm seeking: Adding an active, buffered gain stage can add gain and drive capability and reduce distortion.

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Internally, the Pre90 is the very model of a modern analog preamp. It is fully balanced. It increments gain in 0.5dB steps via relays that switch among resistor arrays. Its active stages are based on nested feedback/composite amplifiers (NFCAs), an increasingly popular construct that can deliver extremely low noise and distortion without resorting to complex, bulky circuits or esoteric semiconductors. On paper, it seemed perfect, with two channels of balanced or unbalanced input and output, adjustable gain, and eye-popping specifications. Despite its low cost and small package, the Pre90 shares many characteristics with larger, more complex, more expensive products, including the recently reviewed Benchmark Media LA4/ HPA4 and the Pass Laboratories XP-32.

One limitation to the naked Pre90 is that it provides just one RCA and one XLR input. Topping, though, has a solution in the form of a matching accessory: The Ext90 costs just $249, connects to the Pre90 with an included umbilical, and adds one more RCA and three more XLR input pairs. The Pre90 doesn't provide any adjustment for interchannel (L–R) balance, so if you need that capability, you'll need to find a place for it elsewhere in your signal path.

Setup
The Pre90 arrives in a nice cardboard box. Its chassis is compact, sleek, well-finished and substantial. The front-panel display is easy to read, with an on/off/function button on the left and the knob to control volume and other settings on the right. The rear panel bears a power switch, an IEC power connector, the RCA stereo output pair, the XLR stereo output pair, the two input pairs (RCA and XLR), and, finally, a multipin connector for attaching the Ext90.

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The Ext90 comes in a matching box with the same chassis as the Pre90. It has no front panel controls or indicators; its rear panel bears, from right to left, a single RCA stereo input pair, three XLR stereo input pairs, and a complementary multipin connector for attaching to the Pre90. When attached by the provided cable, it is automatically recognized and integrated into the Pre90's operations.

With just the base Pre90, you can toggle between the two inputs with either the front-panel button or the included remote control. When the Ext90 is installed, the front-panel button steps through the inputs in one direction. Remote-control buttons permit stepping through the inputs in either direction, but neither permits direct input selection. You can also set level settings independently for each input and output, set the volume at turn-on or for input-switching, and set the brightness of the display. All these settings can be saved.

One peculiarity: You can set the Pre90's output to "XLR only," "RCA only," or both "RCA and XLR." As is typical in devices that offer both, balanced output is 6dB higher than unbalanced output. When you choose XLR output only, the display reflects the XLR output—as you would expect. Similarly, when you select RCA output only, the display shows the RCA output. But when you choose "RCA and XLR" output, the XLR output will be higher than the RCA output by 6dB, but the display will indicate the gain at the RCA output. So, the Pre90 will display 0dB when the RCA is outputting the same level as the input signal—but the XLR output will be 6dB louder than the display indicates. These phenomena are not affected by the choice of input.

I inserted the Topping into my setup between the output from my Coleman 7.1SW source switch and my power amps using the balanced connections. I chose the XLR outputs, inserted the AC cord, flipped the power switch, and configured the Pre90 with the remote control.

The remote control is frustrating. One must aim it carefully at the IR sensor, which is situated at the right side of the display panel but hard to see. The RC is sensitive to poor lateral aim in particular—less accommodating than most other RC's I've used.

I found the knob on the Pre90 chassis somewhat small for comfortable use. It is lightly stepped and smooth, but it lacks the inertia of larger controls on more expensive devices. Assuming you aim well, the remote control works better: Just click the volume buttons for 0.5dB steps or hold them down for continuous linear stepping. As with other volume controls of this type, volume changes are accompanied by quiet relay clicks.

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Listening
Since my original use for the Pre90 was as a low-noise gain stage, I needed to see if it was as quiet and transparent as required for such a self-effacing role. For a quick check, I set it on top of one of the power amps at the speaker end of my 25' balanced interconnects, where it would be easy to swap it in and out of circuit. At unity gain, no change in the sound was immediately discernible. Moreover, at any level setting from –99dB to +16dB, there was no audible noise, even when I pressed my ear to each of the eight drivers in my speakers. So far, so good.

I relocated the Pre90 to the main equipment rack and inserted it into the signal chain. The gain controls in Roon and JRiver were set to "Fixed," and those in the sources (Okto and exaSound DACs and my Oppo player; see the Associated Equipment sidebar) were set to 0dB. I quickly confirmed the essential transparency of the Topping Pre90 across a wide range of attenuation and gain settings. I began listening carefully but not in an organized fashion. I played whatever struck my fancy—my usual procedure as I gradually latch on to the salient characteristics of the sound.

Sooner or later, I stumble on a selection that allows me to define more exactly what a new component is contributing. This time, it was Sol & Pat (Alpha Classics Alpha 757, 16/44.1 PCM download), which pairs violinist Patricia Kopatchinskaja and cellist Sol Gabetta playing works from the 17th century through the present. The first track is startling: Tambourin in C Major by Jean-Marie Leclair opens with a tambourine. Sol and Pat's strings dance along while someone stamps out the beat on the floor. The perspective via the Pre90 (with the other components in the system) is fairly close, tightly presented within a modest ambient frame so that, at a realistic level, the duo is right there in the space between my left and right front speakers. I was hooked and so listened to the rest of this delightfully varied program, ranging from the simple and familiar to the challenging and fascinating.

COMPANY INFO
Guangzhou TOPPING Electronics & Technology Co., Ltd.
Authorized US retailer Apos Inc.
1400 Coleman Ave., #E23
Santa Clara, CA 95050
(510) 858-6585
ARTICLE CONTENTS

COMMENTS
Bob Loblaw's picture

Topping has been building excellent equipment for a few years now. The technical performance absolutely embarrasses many more expensive manufacturers. If accuracy is the goal then it begs the question why anyone would need to spend more than $599 on their pre-amp.

MatthewT's picture

The cost-complainers a bit, at least for this review. OTH, "Made in China" is ringing the Pavlov bell. Great review as well, thanks.

tonykaz's picture

Amazing, Mr.KR, it's like comparing a Kia Soul to a Mercedes S Class.

I trust your assessments in these matters.

The headphone people have also been praising Topping lately, they have superb transducers, support gear and high standards.

Still, it's a bit surprising to see the famous multi-channel authority reaching out to dabble in modest gear like this.

If you're impressed with this piece you must also own outstanding everything .

Tony in Florida

Kal Rubinson's picture
Quote:

Amazing, Mr.KR, it's like comparing a Kia Soul to a Mercedes S Class.

Why would I turn it down? It does represent a full frontal attack on one's perceived biases.

Quote:

Still, it's a bit surprising to see the famous multi-channel authority reaching out to dabble in modest gear like this.

Yes, so I had to buy 3 of them.

Quote:

If you're impressed with this piece you must also own outstanding everything.

It is hard to know if this is tongue-in-cheek but, fwiw, the associated equipment is always listed.

tonykaz's picture

and I read every word you write ! You are one of the greats ( like Mr.JA ) and one of pillars that make Stereophile the impressive institution that it is.

Tony in Florida

CG's picture

TI and ADI have both made incredible progress in their opamps suitable for audio. Great example right here.

georgehifi's picture

Incredible measurements, backed by Audio Science Review (ASR)also
https://www.audiosciencereview.com/forum/index.php?threads/topping-pre90...

Looks to be as good as going direct from dac (with volume) to poweramp/s.
Yet this has adjustable gain settings and anything you could want.

I doffs me hat to this one. And say goodby to highend preamp prices

Cheers George

Glotz's picture

HAHAHHHAHAHHHAHAHhAH

James Romeyn's picture

I enjoyed this review. Kal writes where the rubber meets the road.

I interpret this bold review, comparing ca. $1k to ca. $18k preamps to mean that Stereophile has the guts to risk stepping on the toes of the most highly respected OEMs, even those who pay Stereophile's bills. If I'm correct, then let me make this bold claim in an area where I, a vendor, have absolutely no financial interest.

My friend Luis is a degreed full-time Linux/network system engineer. Luis built my large custom server/streamer computer running the most advanced and refined versions of HQ Player. The main computer parts cost with the best discounts came to ca. $1500; HQ Player costs ca. $165. I don't know Linux from Linus of Peanuts fame; Luis sets up everything remotely. But Luis claims someone versed in Linux could replicate his work.

Two NUCs, both tiny compared to the server/streamer, perform discrete functions: a larger NUC (ca. $250) solely performs Roon library functions (IOW no or as little as possible Roon DSP); the smaller NUC (ca. $150) solely renders with USB output > DAC. Lifetime Roon cost is $500 last I checked.

HQ Player performs extreme filter, up-sampling and demodulator functions in either DSD or PCM. Setup options go on almost to infinity and the author Jussi in Norway constantly upgrades for FREE! The DAC is a Holo Audio Spring 3 KTE, set permanently for true NOS/non-oversampling ("true" means some DACs with "NOS" perform some OS functions.)

Multiple online reports of HQ Player users employing it as described above, including myself, my wife with much better ears than my own, and several friends, prefer this setup over anything else they have heard even cost-no-object. I suspect my server/streamer rig competes with cost no object including dCS rigs in the range of $50k and up.

I suspect, because Herb Reichert is apparently unfamiliar with HQ Player as described (HQ Player on a lesser computer provides commensurately less audio performance) that it would give him a completely new and fresh perspective on the true potential of his Holo Audio May KTE DAC (in NOS mode.)

Compared to the best streaming applications, I suspect spinning silver discs and streaming on consumer laptops/desktops are grossly lacking as professional reviewer tools.

Anton's picture

If I needed a preamp, I would simply jump into this and save loads of cash.

I've read good things about their amplifier, as well.

Nice to see this sort of product get such a focused review, many thanks.

Glotz's picture

Loved this review and your ongoing integrity and honesty in reviewing!

I will NOT China-bash, but please keep in mind this preamp would be much more expensive if made in the U.S.

tonykaz's picture

Schiit builds comparable at comparable prices.

Tony in Florida

georgehifi's picture

Something says to me, they wouldn't measure up like this thing does.

Cheers George

Kal Rubinson's picture

Hold that thought. :-)

tonykaz's picture

What is that something ???

Not just Schiit but all of these Audio Designers have the tools and incentives to build outstanding.

Especially considering that they can sell direct and have direct feedback from their Customer Base.

In the old days of the 1980s, William Z Johnson built to satisfy his Dealer Network .

Now-a-days I can write a note to Paul at PS Audio, Jason at Schiit, Devore, and even Call Manufacturers Direct and get answered by a real person ( maybe even the designer himself )

2020 heading into 2030 seems like a whole new world for us DIY folks, we have much better tools and we don't have to be worshipful to the guys promoting $250,000 record players.

Tony in Florida

Robin Landseadel's picture

If you have been following Amir's reviews at ASR you would be aware that Topping gear always measures great and Schitt gear sometimes measures great and sometimes doesn't.

tonykaz's picture

Measurements vary, I think.

I invest based on listening over a period of time and based on the performance compared to my established standards.

I value Mr.JA's lab bench evaluations and insights.
I also evaluate gear on the Bench and generally agree with Mr.JA's reveals. I'm measuring to confirm proper operation not Sound Quality performance ( which generally bears no relevance to measurements.)

Schiit gear are the best Value for Money products in Home Audio's long History. ( as far as I can tell )

Tony in Florida

Robin Landseadel's picture

Schitt's measurements do vary, depending often on the basic circuit design. And they do offer some of the more unique [and technically dubious] products at unusually low prices, credit where credit is due. Some products, as far as I can tell, are outstanding. Some are underperforming. I have yet to see any measurements of Topping gear at ASR that are not outstanding.

Glotz's picture

The measurements on ASR. The Schiit Modius DAC is a good example. For $200, they compete quite nicely with Topping DACs.

I own it. It is a great placeholder DAC until I can afford something more auspicious.

bhkat's picture

Topping isn't an American or European company that has off-shored manufacturing to China while trying to obscure this fact. It is a Chinese company and therefore is standing on their own. They make great components.

Long-time listener's picture

After listening to the NAD M51 DAC for a number of years, I saw the measurements of the Topping D90SE -- their top of the line -- and decided to buy it. At less than half the price, it was a definite upgrade, with an audible difference. I'm extremely happy with it.

The only thing I don't like about the company -- something that actually makes no difference whatsoever -- is that their name sounds kind of goofy to me. I wonder where they got it. Anyway, I'm not complaining. I'll continue to buy their stuff when it suits my needs.

thatguy's picture

With all these references in the comments to China bashing, do people realize that it is entirely possible to think the Chinese people are great and capable of making quality products and still be shocked by the actions of their government to the point of not wanting to help support them and what that government does.

Jack L's picture

...... and still be shocked by the actions of their government." qtd thatguy.

Hi

I fully appreciate to you have spoken out the background behind the sentiment of China bashing. Not the great Chinese civilization dated back thousands years, but it is "that government" today !!!!!!!!

But let's stop here now as politics should not be discusssed here.

Jack L

michelesurdi's picture

a brave review.time to wakeup to realities.if i had the money i'd buy the pass and keep it for a lifetime,but then i'm a hi fi collector.as it is i'm buying the topping on the strength of J.A.'s work.

synapse-md's picture

I've been a Stereophile reader since 1992, but this is my first time commenting here. I appreciate the rigor and openness with which this relatively inexpensive preamp has been assessed, in similar vein to the recent reviews of Okto Research's products. Top-flight audio quality certainly has become more accessible.

Given the very limited input complement of the Pre90 (Just one set of balanced inputs!), can KR/JA comment on whether there are any subjective or measurable differences when running inputs through the Ext90 vs the Pre90 itself?

The signal paths, to the degree that some audio signals will run through the umbilical alongside power and control, must be at least a little different.

GRBH's picture

Audio Science Review tested this pre amplifier and extension box in December of 2020. One XLR input from the extension box was tested and the results indicated near identical performance to that of an XLR input to the preamplifier itself.

https://www.audiosciencereview.com/forum/index.php?threads/topping-pre90-review-preamplifier.18283/

synapse-md's picture

I missed that! I do wish he had tested channel separation, but agree that from what these data show, there’s unlikely to be an audible difference.

Thanks for the link.

GRBH's picture

You may have missed seeing this, but Amir did an alternative measurement to separation, that of crosstalk. Not clear as to whether the measurement was that of the preamp or extension box. The following was his comment to that measurement.

"Crosstalk was more than good enough for what we need but shy of the best that can be done"

Kal Rubinson's picture
Quote:

Given the very limited input complement of the Pre90 (Just one set of balanced inputs!), can KR/JA comment on whether there are any subjective or measurable differences when running inputs through the Ext90 vs the Pre90 itself?

As far as I can recall, I did not send the Ext90 on to John for testing and I tried the inputs on it only to confirm that they functioned properly.

However, since you asked, I will do a quick test later today and append the results to this message. I do not expect any difference.

synapse-md's picture

Thanks. Appreciate you taking the time to do that.

Kal Rubinson's picture

This was only a brief test. I connected an XLR Y-splitter to the DAC output and its outputs to the main Pre90 XLR input and the #1 XLR input on the Ext90. With a 4-5 musical selections, I did a non-blind A/B comparison between the two inputs, toggling between them, and could not hear any difference in level, tonality or noise. All that was added was the click of the relay at the transition. FWIW.

MatthewT's picture

Very much!

synapse-md's picture

Great to hear. Thanks again for taking the time to do this comparison.

nidaje's picture

Quote: It fits my needs, and it fits my ears, so for me it's a great bargain.
Great review KR.
Although I consider myself to be both experienced and insightful in assessing hi-fi audio equipment, I too have found it hard to believe that equipment in this price range can represent a real and interesting option in the "high end" segment. Thank you for challenging my prejudice on the "right stuff".

georgehifi's picture

"I too have found it hard to believe that equipment in this price range can represent a real and interesting option in the "high end" segment."

The it's just usually the case work that probably tickles your fancy, what's under the skirt "can" be almost the same in monitory/technology/and sound value.

Cheers George

nidaje's picture

I know George and "almost" agree. I am impressed. Given years of trade sanctions the Chinese have no problems producing high performance devices in that pricerange filled with the best components often from the best American/European/Japanese manufacturers. And it seems they are so capable that they can beat the best western electronic designers. No wonder they placed a Rover on Mars too. I am in the market for a new preamp and two of these will probably serve my needs for inputs too.

Robin Landseadel's picture

Great that Stereophile is reviewing Topping gear. I'm a cheapskate, seeking maximum bang for the buck. Have the Topping E30 DAC and the L30 headphone amp that also has limited preamp functions. Very nice, and at less than $300 for the pair, very cheap. Hope you get around to the Topping D90SE DAC. If ASR is right, it's SOTA for $900.

JRT's picture

Again... Thank you for another interesting review of an interesting component.

Seems strange that they would conciously choose to not include some facility to control separate levels of attenuation on each channel, some means of adjusting channel balance.

Kal Rubinson's picture

I agree with you even though I have not had a need to use a balance control for some years now. There are other points in my signal chain where it can be implemented, so I like that the Pre90 is so simple in its functions: Source selection and gain control, that's all.

remlab's picture

..with excellent loudspeaker QC and proper loudspeaker/listener placement, there really isn't much of a need for balance control anymore

remlab's picture

..Stereophile reviews John Yang's latest Topping amplifier design too. Other than total power, it almost reaches EIGENTAKT levels of performance.

tonykaz's picture

It feels like you broke thru the ice as a High Level Enabler for we budget hopefuls.

I suspect that you will now have an enthusiastic range of admiring readership searching for meaningful insights into all things Audio.

I've always seen you as an exploring navigator of hard to reach Worlds.

Congratulations,

Tony in Florida

georgehifi's picture

@John Atkinson

Seeing you had the top off this Pre90 did you see what opamps are used? or is the active stage discrete circuitry.

Thanks George

John Atkinson's picture
georgehifi wrote:
Seeing you had the top off this Pre90 did you see what opamps are used? or is the active stage discrete circuitry.

I'm afraid I didn't look inside the Pre90. The internal photo was supplied by Topping.

John Atkinson
Technical Editor, Stereophile

David Harper's picture

Not at all like comparing a Kia to a Mercedes. In that case there are real objective differences in build quality and performance. In the case of preamps, not so much

stanzani's picture

Hello Kal
I would have liked to read your opinion when comparing the pass and the topping in situation w/i and w/o preamplifier further taht topping vs pass. And yes, I would have like a bind comparison (but I am asking too much ;) )
It could be embarassing to state that no divverence between the big and the small boy :)

John Atkinson's picture
stanzani wrote:
I would have like a blind comparison (but I am asking too much ;) It could be embarrassing to state that no [divergence] between the big and the small boy :)

When I studied statistics at university 50 years ago, I learned that tests cannot prove a negative. If a test produces statistically insignificant results, that does not mean that the items being compared were identical. Instead, the results mean that if a difference exists, it was not detected under the specific conditions of the test.

John Atkinson
Technical Editor, Stereophile

reynolds853's picture

To be clear, your only comment about the impact about adding the Topping was single sentence:

Without it, I noted marginally less weight and a bit less dynamic impact.

"Marginal" and "a bit" suggest that pre-amps do not impact sound much for DACs, I suppose. I can see the case to be made for low gain components, though.

TJ's picture

Kudos to their engineering team for such an impressive product. Customer satisfaction may suffer unfortunately from the frustrating remote (cost-cutting?), Topping's QA and customer support problems, and hidden expenses for warranty service (return shipping to China plus high customs entry fees). Do we know what the failure rates are for Topping products? The user anecdotes on Amazon and the forums are disconcerting. If the failure rates are high as some say, buying one may be a game of chance.

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