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.
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 (LR) 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.
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 outputas 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 signalbut 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 particularless 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.
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 fancymy 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.
FAQs
Do preamps affect sound quality? ›
The sound contribution of preamps is not so much in its frequency response but in the texture it imparts on the sound. However, a preamp shapes the sound to a much lesser degree than one would think. Usually, its sound character only becomes obvious at high gain settings or when you drive it into distortion.
What does a preamp do audiophile? ›The purpose of a preamp is to amplify low level signals to line level, i.e. the “standard” operating level of your recording gear. Microphone signals are usually way below the nominal operating level, so a lot of gain is required, usually around 30-60 dB, sometimes even more.
How does preamp boost signal? ›See, the input of most audio gear expects a line level signal to deliver optimal audio quality. A preamp prepares the signal by converting a microphone level signal to a line level signal so other equipment can process it. This is known as proper gain staging.
What is the purpose of a pre amplifier? ›In a home theatre system, the pre-amplifier performs two main functions: it handles switching between different line level sources and boosts the signal before sending it to the amplifier. A weak electrical signal becomes strong enough for additional processing, preventing noise and offering cleaner output.
Which is better phono or line? ›A PHONO signal is the tiny signal that comes directly form the turntable cartridge whereas a LINE signal is an amplified version of the PHONO signal. A LINE signal has the same size/strength as a signal from other audio source like CD players whereas a PHONO signal is much weaker.
How do I choose a preamp? ›Choose your phono preamp according to the sound quality required. Depending on the type of music you play and naturally the sound quality you are looking for, you will have to consider different phono stages. Sound quality will differ depending on the components used by the manufacturers, and the technological bias.
Do I need a DAC if I have a preamp? ›You do need a DAC if you have a preamp to get quality audio. A DAC converts stored digital audio data to analog, while a preamp takes the converted data and increases its gain, and removes any signal distortion.
How do I know if I need a preamp? ›So Do I Need a Preamp For My Turntable? It depends… If your turntable does not have a built in preamp, and your amp or receiver does not have an input labeled “phono”, then you will need to purchase a preamp for your turntable (otherwise known as a phono preamp).
Does a DAC go before the preamp? ›It doesn't matter. A DAC takes a digital stream and turns it into a line-level stereo analog signal, just like the output from your CD player, tuner, phono stage, (or cassette deck!). So if you can connect a CD player or tuner to your preamp or integrated amp, you can connect a DAC to it.
How much gain should a preamp have? ›Technical Editor Hugh Robjohns replies: It is certainly the case that nearly all of the mic preamps built into budget and moderately priced desks and channels generally offer a maximum of around 60dB of gain, and this is usually more than enough for recording the vast majority of close-miked sound sources with typical ...
Does preamp increase volume? ›
Preamp volume is the process that makes the sounds being captured by a microphone become audible. It is measured in dB, and generally, a preamp adds up to 60dB of volume to the signal. The correct amount of volume to be added depends on the microphone, the instrument, and the preamp itself.
Does a preamp reduce noise? ›Preamp Noise
Well, in most cases less than you'd expect. Usual studio grade preamps add around 3–6 dB of noise. But there are some ultra low noise preamps that contribute less than 1 dB of additional noise.
As the name suggests, a headphone amp amplifies sound inside a headphone (or earphones). In contrast, a preamp amplifies audio signals going into an audio-output device like speakers or music system.
Do preamps make a difference? ›A Clean Front End
A high quality microphone preamp, however, will do much more than just make your mic level louder. It will deliver a cleaner, more accurate signal, with higher gain, lower noise, less distortion, and more headroom.
Three basic types of preamplifiers are available: current-sensitive preamplifier. parasitic-capacitance preamplifier. charge-sensitive preamplifier.
Do I set my turntable to line or phono? ›Tutorial Tuesday - Phono and Line Switch on Turntable - YouTube
Is RCA phono or line? ›Explaining phono & line inputs
Line outputs are typically unbalanced, meaning that they have one single cable carrying both left and proper audio channels. Phono: Often called 'RCA' plugs, these connect from the turntable's output to an input on a stereo receiver or integrated amplifier.
Record players are quiet by nature. They produce an extremely low electrical signal that needs to be amplified two times. What is this? It first gets amplified by a preamp (either internal or external) which brings it up to the same line level as a CD player.
Are tube preamps worth it? ›A tube preamp tends to have warmth and smoothness that a solid-state often lacks. Because of the way they work, driving the tubes creates a subtle but smooth distortion adding a pleasing character to the tone. This doesn't necessarily constitute distortion in the sense of 'overdrive' but rather more color or character.
Do all preamps have a phono stage? ›Most new models of amps and receivers don't come with a built-in phono preamp, but they may have a label that says phono anyway. Another way to determine whether or not your model has a phono stage is to plug in your record player and try turning up the volume.
What is a hybrid preamp? ›
An audio amplifier that uses both tubes and transistors. The tube circuits drive the MOSFET transistors at the output stage because transistors can generate more power with less heat and reliability issues.
How do I connect a DAC to a preamplifier? ›You can definitely connect a DAC to a preamp. You want to connect the DAC's output to the preamp's input using the appropriate audio cable. This will send the output audio from the DAC to the preamp for preamplification.
What is DAC in audiophile? ›A digital-to-analog converter (DAC) that is geared to fans of high-quality sound. Audiophile DACs support resolutions of 192 kHz and beyond with error correction. They often include multiple inputs such as TOSLINK, coaxial cable and USB and may include selectable upsampling (see upsample).
Is a DAC also a preamp? ›Now that many DACs provide the option of volume controlled outputs, in a digital system, the DAC can potentially be used as a preamp. Unfortunately, the sensitivity of many amps is too low to be fully driven by a DAC's RCA/XLR outputs.
Can I use my amp as a preamp? ›Yes, if the amp has a preamp output then that can go into a power amp. Without that, you need an expensive go between to convert a speaker output into preamp level or DI level output, often called a “power soak” feature.
Is a preamp a speaker? ›(PREAMPlifier) Meaning "before the amp," the preamp is the primary control unit in a stereo or home theater system. It switches low-level signals from audio and video sources to the audio amplifiers, which boost the preamp output sufficiently to drive the speakers. The preamp always includes the volume control.
How do you use a preamp with a receiver? ›Locate the Main In and Pre Out inputs with jumpers on the rear of the vintage receiver. Remove the jumpers from the inputs on the receiver and store them in a safe location. Plug RCA cables into the Pre Out input on the receiver with the red cable in the Right input and the white cable into the Left input.
Can I use multiple preamps? ›You can use two preamps as long as you balance the gain on the preamps to have enough headroom, so the audio signal doesn't clip or distort. You can either connect the preamps in series or parallel and mix the two tones together.
Does DAC affect volume? ›The Volume Issue
If you are going to get a DAC for your high-impedance headphones and don't get a power amp, you're not going to be able to play music at the volume you like. Higher impedance usually translates in high detail and lower volume at the same time.
You need both a DAC and an amp to get the best listening experience. A DAC converts stored audio signals from digital to analog form, making it possible to listen to sounds, while an amp powers your speakers, making the signals audible. Therefore, you can't enjoy quality music without either.
Does a preamp boost volume? ›
Preamp volume is the process that makes the sounds being captured by a microphone become audible. It is measured in dB, and generally, a preamp adds up to 60dB of volume to the signal. The correct amount of volume to be added depends on the microphone, the instrument, and the preamp itself.
Does external preamp improve sound? ›An internal preamp is more convenient and generally much cheaper. But it rarely gives you good sound quality. External preamps sound much better, but they cost more and require some setup.
Do all preamps sound the same? ›No, they're not all the same. There are generally differences in the transient response, as well as frequency response, and other more esoteric factors. Whether these differences are dramatic or whether you can hear them at all depends entirely on the source.
Do tube preamps sound better? ›As a tube creates distortion it produces harmonics which are known as 'even harmonics'. Essentially these are tones which are the same note but are produced higher in octaves. This is why typically a tube amplifier is said to sound better, because the harmonics it produces are much more pleasing to the user's ear.
How do I know if I need a preamp? ›So Do I Need a Preamp For My Turntable? It depends… If your turntable does not have a built in preamp, and your amp or receiver does not have an input labeled “phono”, then you will need to purchase a preamp for your turntable (otherwise known as a phono preamp).
Do preamps really make a difference? ›A Clean Front End
A high quality microphone preamp, however, will do much more than just make your mic level louder. It will deliver a cleaner, more accurate signal, with higher gain, lower noise, less distortion, and more headroom.
It's not usualy a good idea because preamp outputs are line level and preamp inputs are mic level. You would be feeding a (relativly) very high level signal into something that wantls a very low signal. You can do it, but you're probably reducing the benefit of one by having to turn it down so far.
Do I need a phono stage and a preamp? ›A phono preamp (also known as a phono stage) is a complete necessity when it comes to getting your vinyl setup off the ground: they provide standard equalisation – correcting sonic imbalances left over as a manufacturing necessity – and boost the weak signal from your deck's cartridge to a level that allows you to ...
How much gain does a preamp have? ›Usually, you're looking at anywhere between 30-60dB of gain increase; some microphone types, such as ribbon mics, require even more gain. See sidebar for some technical info about preamp gain.
Should I use a preamp for vocals? ›So “do you need a preamp to record vocals?” You do need a preamp to record vocals. If you are recording music with an interface into your computer, chances are you are already using one. Most big brands add a microphone preamp to all XLR inputs of an audio interface.
Do I need a preamp if I have an amp? ›
Yes, you need both.
A power amp expects a signal at line level; a preamp is needed for that. You could technically go from a preamp, straight to active speakers without an external dedicated power amp. But, only because active speakers have built-in power amps for each driver. It wouldn't work with passive speakers.
A preamplifier (preamp) is a device that converts a weak electrical signal into a noise-tolerant audible output signal, while an amplifier (power amp) is a device that can increase the power of the output level of any signal, albeit with some added noise.
Are expensive phono preamps worth it? ›Higher-end phono preamps, according to Randall, are “also capable of accurately amplifying a wider range of cartridges.” In particular, they can more adeptly handle rarer Moving Coil (MC) cartridges, which require much more gain and have different electrical requirements than their more common Moving Magnet brethren.
Are tube amps obsolete? ›Guitar amps are not becoming obsolete. There are few reasons for that. First, software programs are still not viable enough to provide a worthy replacement for guitar amps, especially for live playing. Second, good quality guitar amps still sound better than any computer software.
Why do tube amps sound better than solid-state? ›Tubes, like analog recordings, have a more full-bodied sound than transistor gear. There's a "roundness" to tube sound that solid-state gear never equals. Tubes are less forgiving about mismatches, so to get the best out of a tube amp it must be used with just the right speaker.
Are Ruby 12AX7 tubes good? ›The Ruby 12AX7AC5 High Grade Preamp Tube is an extremely popular 12AX7A tube and our best seller here at Eastgate Music. It's Ruby Tubes highest quality 12AX7's! All Ruby pre-amp tubes are properly tested for quality assurance.