Today, an increasing number of audiophiles are discovering the numerous benefits of adding a passive preamplifier in their car audio systems. A passive preamplifier does the role of switching input and controlling volume without affecting the quality of the audio signal. That means that a passive preamp is less likely to pick noise or color along the way.
Essentially, a passive preamp works by controlling the volume of an audio signal without involving any power source. Most passive preamps control the volume of an audio signal with the help of a variable resistor. Others work with a transformer to convey and attenuate an audio signal electromagnetically.
There’re several advantages of a passive preamplifier. First, you don’t necessarily need gain with a preamp. Most amplifiers have enough power to amplify a preamp output. Thus, there’s no need to amplify an audio signal twice. With a passive preamp, there’s no gain or amplification. You only control the volume or switch inputs and leave an amplifier to do the amplification.
Second, you don’t need any coloring in an audio signal. If you prefer listening to a music recording in its original quality, then you don’t have to meddle with it. Active preamps usually add color to an audio file while passive amplifiers don’t. There’s less manipulation and circuits in a passive preamp such that there’s no significant coloration.
Third, passive preamps sound great. Most audio sources can deliver a premium quality signal through a passive preamplifier without the need to buffer or amplify the signal. Thus, top-quality passive preamps often produce higher quality sound than most active amps. Also, passive preamps are more affordable than most active preamps due to the fewer parts required, hence a lower cost of production.
In this article, we’ll review the best passive preamplifiers to ensure you’re feeding your amplifier with a top-quality audio signal. Consequently, you’ll enjoy premium sound output from your music system.
Quick Comparison Table
Top 5 Passive Preamplifier
Not all passive preamps are the same. Their performance ranges from poor to exceptional. Thus, it’ll help to do thorough research when shopping for passive preamps. We’ve reviewed the top 5 passive preamplifiers to make your shopping easier.
1. Best Overall- Nobsound JMQ399H-FS
Nobsound JMQ399H-FS is our best overall pick. Nobsound has specially designed the preamp to ensure that there’s little or no loss of quality in the audio signals passing through the preamp. Overall, it features a great build quality.
- Copper gold-plated RCA ports- One of the most outstanding features of this passive preamp is the gold-plated RCA ports. Gold and copper are some of the best electricity conductors. Thus, gold-plated RCA input and output ports allow for pure sound quality. They ensure that sound doesn’t cut in and out. Also, gold plating protects the RCA ports from oxidation.
- High precision adjustment- You definitely want the best volume control when using a passive preamp. Luckily for you, this passive preamp allows for high precision volume adjustment. The volume control adjusts volume responsively and with high precision. You’ll be able to hear a change in volume at every turn of the volume knob.
- Lossless transmission- As a serious audiophile, you want the best quality and original sound production from your music system. With this passive preamp, you’re assured of getting original sound quality due to its lossless transmission of audio signals. It doesn’t have an amplifier circuit such that it doesn’t alter the character of music.
- Aluminum chassis- Nobsound has designed this preamp with an aluminum chassis. Aluminum is a lightweight material, thereby keeping the weight of the preamp low. It’s strong despite being lightweight to keep the interior components protected from damage. Also, it resists corrosion for enhanced durability.
- No gain- Another reason why this passive preamp is a top choice is its lack of gain. It outputs the amount of voltage it’s fed as it doesn’t boost the voltage. For instance, if you feed it with an audio signal of 1V, it’ll output a maximum of 1V. That means it doesn’t interfere with the sound quality.
- High-end black finish that matches most car interiors
- Great for use with power amplifiers and active speakers
- High-fidelity sound output for the best listening experience
- It doesn’t introduce any noise or distortion in the sound signal
- Compact size for a more concealed installation
- No notable issues
Nobsound JMQ399H-FS passive preamplifier proves to be a great choice for getting undistorted sound output when hooked to an active speaker or amplifier.
2. Best Audio Switch: ONE Little Bear MC3
ONE Little Bear MC3 is designed as a 2-in and 2-out passive preamplifier switch and audio splitter. It works as a switch without any power supply. It looks well designed and feels very sturdy. It’s very easy to use despite featuring two different functionalities.
- Rotary selectors- It comes with two knobs that work as rotary selectors. You simply rotate the selectors depending on whether you want to use it as a signal convertor or a switch. The rotary selectors are marked, making it easy to use the gadget.
- Switch function- You can use it as a switch. In this case, it allows for switching between different amplifiers or sound sources. For instance, you can have two inputs and switch between them as needed. Also, you can have 2 outputs and switch between them as needed.
- Signal converter- Also, ONE Little Bear MC3 works as a signal converter. For instance, you can input balanced XLR and convert it to output unbalanced RCA. Also, you can input unbalanced RCA and convert it to output balanced XLR.
- Small-sized- Despite having multiple functionalities, this passive amplifier features a small-sized design. Consequently, you can use it for either home use or desktop use. It’s compatible with devices that feature RCA and XLR inputs and outputs.
- Silent and smooth operation- Additionally, you’ll enjoy operating it silently and smoothly. There’re no clicks or pops when switching between the outputs and outputs. Consequently, you’ll enjoy smooth transitions when switching from one input or output to the other.
- All the terminals are sturdily built in place
- It’s lightweight, making it possible to carry it from your home to the office and vice versa
- It’s easy to install and use the preamplifier for all the supported functions
- A user manual is provided to make it easier for a first-timer to use it
- Doesn’t degrade the sound quality when switching outputs or inputs and when converting signals
- The knobs don’t align perfectly with the markings
ONE Little Bear MC3 is a perfect choice when working with two different inputs or two different outputs and you want to switch between them without making new connections all the time.
3.Best Build Quality: SOLUPEAK C3r
SOLUPEAK C3r passive preamp features a light blue finish that looks quite attractive for audiophiles who love bright-looking audio equipment. Its functionality resembles our first pick, the Nobsound JMQ399H-FS. However, SOLUPEAK C3r is more affordable than our first pick.
- Solid casing- One of the most notable features is the impressive case enclosing the passive preamp components. The case is made of solid aluminum material. It’s sturdily built for maximum durability and longevity.
- Wide compatibility- Zhuogang P16 is designed to work with all kinds of audio sources that work with RCA connections. You can hook up any RCA source with an analog signal including devices like TVs, PCs, DVD players, and CD players among others. Also, you can connect the output to any active speaker or power amplifier that supports RCA connections.
- Hi-Fi sound output- SOLUPEAK C3r features a design that allows for the production of high-fidelity sound. For instance, it doesn’t have any gain boost. That means its sound output isn’t altered. As a result, there’s no loss of the original sound quality.
- 2 inputs and outputs- There’re 2 RCA inputs and 2 RCA outputs at the back of the passive preamp. The available inputs and outputs are for the left and right channels. Thus, it can process stereo sound.
- Volume knob- At the front of the passive preamplifier is a dedicated volume knob. The volume knob is also made of aluminum for enhanced durability while keeping its weight low. It adjusts the volume level precisely.
- Affordable price range for the quality and performance
- Easy to connect with RCA cables, thanks to the clearly labeled ports
- Gold-plated RCA inputs and outputs to prevent oxidation
- Silver brush surface finish for a more sleek look
- Only supports one audio source and one output at a time
Overall, SOLUPEAK C3r features a more sturdy construction at an affordable price range. Thus, it’s ideal for anyone who needs a durable but budget passive preamp.
4. Premium Pick: Bellari PP532
Bellari PP532 is our premium pick. While our first three picks feature an aluminum chassis, Bellari PP532 features a steel finish. It also differs from our other in that it comes with a 3.5mm AUX input and 4 RCA inputs while the first three only feature RCA inputs.
- AUX input- We include Bellari PP532 in our list of the best passive preamplifier due to its uniqueness. For instance, it comes with an AUX input, unlike all other passive preamps in our review. You can connect it to any audio source that has a 3.5mm aux output.
- Multiple RCA inputs- While other passive preamps in our review feature a single RCA input, this preamp comes with 4 RCA inputs. That means you can connect up to 4 different audio sources via RCA. This is especially important when you have multiple audio sources and you want to connect them all rather than connecting one audio source at a time.
- Input selector knob- You can easily select the RCA input with the help of the input selector knob. The selector knob has markings for inputs 1, 2, 3, and 4 for easier input selection. As a result, you’ll find it easier to switch between the inputs depending on the audio source you want.
- Steel casing- Also, Bellari PP532 features a steel casing. The casing is extremely sturdy to resist impact. Its strength and toughness keep the interior components protected from damage. The red color on the casing gives it a very bright finish, which is ideal for individuals who prefer brighter colors over darker colors for their audio equipment.
- Premium sound quality- Although this passive preamp offers several inputs, it works without the need for a power supply. It has a simple working mechanism that allows for distortion-free audio.
- Responsive volume control knob
- Sturdily built for enhanced longevity
- The AUX input and RCA allow for tight connections
- It doesn’t modify the original audio signal
- Its higher price range is not ideal for someone working with a very tight budget
Searching for a passive preamplifier that can offer premium performance? If so, Bellari PP532 is exactly what you need, especially if you’re willing to pay a little more for top-quality performance.
5. Budget Pick: DollaTek ALPS16
DollaTek ALPS16 features a simple design and straightforward operation. It’s similar to our first and third picks in terms of inputs and outputs, featuring a single L&R RCA input and a single L&R RCA output.
- Silver finish- One of the features we like most about this gadget is its brushed silver finish. This finish makes it look very glossy and classy. Also, the brushed finish is not susceptible to staining.
- Very compact and lightweight- If space is a problem for you, this preamp is your perfect choice. It’s very compact and doesn’t take any significant space. You can easily conceal it. Also, it’s lightweight for enhanced portability whenever you want to carry it along with you.
- Pure copper RCA with gold plated finish- All the RCA ports are made of pure copper for maximum audio transfer without loss in quality. Additionally, the RCA ports are plated with gold to prevent them from oxidation that results in rust.
- Aluminum knob and chassis- You can rest assured that you’re investing in a long-lasting passive preamplifier. Its components are enclosed inside an aluminum chassis. The aluminum chassis material keeps the interior components protected from impact that may cause damage. Also, the volume knob is made of aluminum.
- Affordable price range
- High precision and excellent volume adjustment
- Very well made with a very strong chassis
- There’s no noticeable loss in the quality of the audio signal
- The L&R RCA inputs and outputs feature the same color rather than the standard red and white coloring
DollaTek ALPS16 stands out as the most affordable passive preamplifier in our review. It’s most suitable for someone working with a very tight budget.
Factors to Consider When Choosing a Passive Preamplifier
While there’re numerous passive preamplifiers to choose from, they’re not made equal. Their performance varies widely. You can only stand better chances of picking the right option by considering certain important factors including:
1. Types of Inputs and Outputs
The kinds of inputs that come with a passive preamp vary from one model to the other. Here, consider the kind of audio source you want to connect. For instance, if your audio source only features an RCA output, choose a passive preamp that has an RCA input. Similarly, if your audio source only features an AUX output, choose a preamp with an AUX input for compatibility. Also, ensure the output on the passive preamp matches with the input supported by the active speaker or amplifier you want to connect to.
2. Number of Inputs and Outputs
Another important factor to consider when choosing the best passive preamplifier is the number of inputs and outputs on the preamp. If you need to connect several audio sources or several outputs, ensure the passive preamp has several inputs and outputs as needed.
It’ll help to invest in a passive preamp that offers the most important controls and functionalities. For instance, it should have a volume control mechanism to turn the volume up or down as needed. If the passive preamp has several inputs or outputs, ensure it has an input or output selector knob for easier switching between different inputs or outputs as needed.
4. Ease of Use
Also, go for a passive preamplifier that’s designed for enhanced usability. For instance, any control knobs should be labeled appropriately. If there’s an input or output selector switch, it should be properly labeled with perfectly aligning markings. Additionally, the inputs and outputs should be labeled.
5. Build Quality
When buying a passive preamplifier, it’ll help to spend your hard-earned money on a durable product. Ensure the option you’re choosing is sturdily built. The chassis should be made of strong material. The inputs and outputs should be plated to prevent oxidation and rust. Also, the inputs and outputs should allow for tight cable connections.
Passive preamplifiers offer a perfect way of controlling the volume of an audio signal or switching inputs and/or outputs without altering or amplifying the audio signal. However, it takes some effort to find a passive preamplifier that offers excellent performance. Luckily for you to have visited this page, you can find the best passive preamplifier for your needs from our reviews. Also, keep in mind the aforementioned considerations to make when shopping for a passive preamp.
Michael Evanchuk is a San Francisco-based sound engineer with 20 years’ experience installing, troubleshooting, and repairing commercial, automotive, and household sound equipment. Evanchuk owns an auto stereo center, where he offers highly competitive car audio installation and repair services. He has written dozens of articles on different sound engineering topics, all of which have been published in leading journals, blogs, and websites.