Can’t find the best 5751 tube for your amp? Let us help you make an informed decision.
Regardless of whether you’re a seasoned or a proletarian bassist, sooner or later, you’ll need to replace your depleted preamp tubes with new ones. Or it could be that you’re looking to fine-tune the quality of audio. You’ll have to opt for a brand new preamp tube for boosting or reducing the gain in both cases.
It is primarily harmonicists, mouth organists, French, blues, mouth, and jaw harpists who find preamp tubes convenient for modifying the gain factor.
However, many harpists cannot make up their minds whether to go for a 5751 or a 12AX7 preamp tube. This review takes a close look at the four top-notch 5751 amp tubes, followed by a bare-bone comparison between the two tube types.
Best 5751 Tubes – 5751 Tube Comparison
| Image | Model | Price |
|---|---|---|
| JJ 5751 Preamp Vacuum Tube (Top Pick) | Check Price |
 | Sovtek 5751 Vacuum Tube (Close Runner-Up) | Check Price |
 | Tung-Sol 5751 Dual Triode Preamp Tube | Check Price |
 | Tung-Sol 5751 Gold Pins Tube | Check Price |
1. JJ 5751 Preamp Vacuum Tube (Editor’s Choice for the Best 5751 Tube)
The JJ 5751 is the best 5751 tube on our list.
Are you a harpist or a harmonicist looking for a lower-gain preamp tube for polishing up the fizzy sounds delivered by your amp? Then you do not need to look further than the 5751 Preamp Vacuum Tube from JJ Electronics. With a gain factor of 70%, this 5751 preamp tube will make the harmonica’s notes belted out by your amplifier sound more sonorous.
At the same time, the JJ 5751 preamp tube helps adjust, tone down and modulate the volume-range of the guitar amp. Blues and mouth harpists looking to replace the OEM 12AX7 tube will find the JJ 5751vacuum tube a perfect replacement. The JJ Electronics’ 5751 preamp vacuum tube offers harpists a clear audio quality gain over 12AX7s at the same wattage.
The JJ 5751 comes in perfectly handy for accomplishing an excellent tube tone by turning up the gain factor. On the other hand, this noticeable improvement in gain happens without any volume loss. You can rest assured that this preamp tube will render the volume range more utilizable and overdriven electric guitar sounds less thumping.
The JJ 5751 Preamp Vacuum Tube is your best bet when you want your audience to hear warmer, more crispy tunes
Features
- Hi-MU or high voltage gain
- Dual triode
- 100% solid tone
- The high heat-resistant glass tube
Pros
- Furnishes a perceptible gain in audio superiority compared to a 12AX7
- It offers a reasonable balance of highs, mids, and lows
- It helps the amp to reproduce crispier and crunchier notes
Cons
- If you’re a heavy metal specialist, reducing the gain for a superior overdrive may not be conducive.
2. Sovtek 5751 Vacuum Tube (Close Runner-Up)
The Sovtek 5751 preamp vacuum tube rivals the JJ Electronics 5751 tube in quality and standalone features. On the other hand, the 5751 amp tube from Sovtek costs much less than the 12AY7 used extensively in traditional Fender tweed amps.
Similarly, the Sovtek 5751 vacuum tube serves as an impeccable replacement for the 12AT7 reverb driver tube.
One practical benefit that harpists and guitarists stand to reap is the more significant gain (up to 70%) than 12AT7 and 12AX7. When you plug in this tube in your guitar amp, you’re guaranteed warmer tones and more brittle notes. The 5751 amp tube by Sovtek goes a long way in balancing out audio quality, making it a practical phase inverter.
With the Sovtek 5751plugged inside the amp, you can intensify the amp’s front end to a considerable extent. Talking about this Sovtek preamp tube’s durability, it is made of toughened glass and so has an extended functional life. To say last but not least, if you want your amp to deliver crunchier audio with crystal clear distortion, then Sovtek 5751 vacuum tube is the way to go.
Features
- An affordable option for using in classic tweed guitar amps in place of 12AY7, 12AT7 or 12AX7
- Robust build quality
- It can help reproduce the sound and tone you intend to extract from your amp.
Pros
- The overdrive audio has a crunchy quality with crystal-clear distortion
- Perfect tube for phase inverter and even for mechanical and digital reverb tube positions in amps, multi-effect pedals, stompboxes, and rack mount units
- Offers reasonable leeway for cleaner headroom
Cons
- The low-gain in amp quality is hardly evident to make a difference.
3. Tung-Sol 5751 Dual Triode Preamp Tube
This Tung-Sol 5751 tube is undoubtedly one of the most performance-oriented 5751 tubes produced in Russia with an affordable price tag. Initially, Electro Harmonix used to own this 5751 preamp tube brand before the Russian manufacturer took it over. However, the change in ownership has not affected or impacted the quality of this 5751 preamp tube.
The Tung-Sol tube comes to your aid when you are looking to replace your amp’s stock 12AX7 with a tube for ensuring lower gain. You can take it for granted that the Tung-Sol 5751 amp tube will deliver the results you’re looking for, provided you’re applying the appropriate circuitry.
Since this Tung-Sol preamp tube is a dual-triode tube, each tube comes with two distinct gain stages. Featuring nearly the exact specifications as that of a 12AX7, the 5751 Tung-Sol tube serves as a perfect replacement for the former.
Features
- Dual triode preamp tube
- Russian made
- Having a high-mu of 70, this 5751 is a specialized 12AX7
Pros
- Offering 30% reduced gain, this 5751 is ideal for toning an amp and fine-tuning undesirable distortion.
- Top-quality 5751 preamp tube available at a very moderate price point
- If you use the proper circuitry, the tube will work you want it to
Cons
- It could cause abnormally high distortion in many cases
- Extremely susceptible to malfunctioning
4. Tung-Sol 5751 Gold Pins Tube
The brand new gain-tested Tung-Sol Reissue 5751 Gold Pins Vacuum Tube comes across as the state-of-the-art edition of the original Tung-Sol 5751 tube. The Tung-Sol 5751 gold pin tube produced in Russia works well for harmonicists looking for a 5751 priced affordably. Guitarists and bassists know too well that, more often than not, only a 5751 can substitute a 12AX7.
As a tube with a lower gain, the 5751 preamps can give you your desired output, provided you’re using the proper circuitry. This 5751 Gold-grade preamp has a triode balance varying between 15% and 20% (could be higher based on your amp) with microphonics and low noise. This 5751 tube review wraps up our list.
Features
- The reissued version of the classic 5751 tubes from Tung-Sol with gold pins
- Compatible for use in guitar preamp or phono stage
- Boost tonal range of each amp in the V1 zone
Pros
- Amp will not become deafening even when you turn on the volume
- Works excellently with the use of appropriate circuit
- Solid construction
- Very pocket-friendly
Cons
- Often the lower gain could lead to high distortion and sometimes even malfunction.
What’s The Difference Between 5751 and 12AX7 Tubes?
12AX7 vs. 5751? We know a thing or two about that 🙂
As an accomplished guitarist or harmonicist, you’ll often have to swap out your old amplifier tube with a new one. For most harpists and guitarists, this (replacement) usually boils down to choosing either a 5751- or a 12AX7 preamp tube. We will offer you a detailed lowdown of both the 5751 and 12AX7 tubes used in guitar amps in the following paragraphs.
At the same time, we’ll focus on both the tube types’ advantages and drawbacks based on the ‘gain factor.’
5751 vs. 12AX7 Tube: Gain Factor and Audio Quality
Guitarists need to plug in or replace a preamp tube to adjust and polish the sound for fine-tuning the audio quality. Replacing the stock preamp tube with an amp tube having a somewhat different mu or amplification factor usually alters the sound quality. The amplification factor of a preamp tube implies the tube’s potential by which it can amplify or intensify the input signal.
The capacity or the rate by which a preamp tube can boost the input signal is called its gain factor. Putting things into perspective, a 5751 tube features 70%, while the 12AX7 has a 100% gain factor. So if you plug in a 5751 tube into the amp’s socket that’s compatible with a 12AX7, there’s a 30% shortfall in gain.
For the harpist, this reduction in gain means that the amp will not only operate with less noise, but the audio quality will also change. Most harmonicists replace a stock 12AX7 tube with a 5751 to reduce the gain for experiencing a range of sounds. On the other hand, trimming down the gain helps bring down the amp’s power for getting rid of feedback. But if you want sharper and more thumping notes, increasing the gain factor is par for the course.
12AX7 Preamp Tube
12AX7 preamp tubes serve as standardized amp tubes providing a 100% gain. So if you’re looking for the optimal mix of highs, mids, and lows, settle for a 12AX7. With 12AX7s, there’s absolutely no loss in tonal quality, which is what you’ll look forward to, especially if you’re into heavy metal and rock.
You can plug in a 12AX7 tube into any amp irrespective of the circuitry, with some notable exceptions. With a 12AX7 (no matter whichever brand you opt for), you can make the best audio quality.
Advantages
- 100% gain without any signal loss
- A harmonious blend of highs, mids, and lows
- The highest highs and lowest lows effectively amplified
- Works with almost all amp circuitries
Drawbacks
- Overly crisp audio more often brings microphony to the fore
- Audio warping and feedback might become noticeable
5751 Preamp Tube
5751 tubes offering a 70% gain, by and large, furnish a relatively equitable mix of highs, mids, and lows. Hence the musician and his audience enjoy all the nuances and shades minus the flatness experienced at lower tones. The fact that 5751s enjoy a high level of popularity with musicians is because they help amps deliver clean and crisp audio.
However, on some occasions, the audio quality may fall short when it comes to creating impressions. Unlike most vacuum tubes, 5751s do not exhibit microphone-undesirable electrical signals that adversely affect audio quality. Nevertheless, before choosing a particular 5751 tube brand, make sure it is companionable with your amp circuitry.
So, are 5751 and 12AX7 interchangeable? Yes, any 12AX7 is a good 5751 tube equivalent and vice versa.
What about 12AX7 vs 5751 vs 12AY7 vs 12AT7? 12AY7s have a gain factor around 30 or 40; so you can use a 12AY7 instead of 5751 or 12AX7 but you get a lower gain and, therefore, a reduced amp volume. 12AT7 have a gain factor similar to the 5751’s but their plate current is ten times of a normal 5751 tube, and it makes a huge difference in a tone driver position.
Overall, if you want to remember just one thing – use new 5751 tubes instead of 5751 tubes because any other tube will change your amp’s sound and you never know exactly how.
Benefits
- Can replace different amp tube types
- Lower gain audio yet clearly detailed and textured
- Lower gain hence less noise
Limitations
- The tonal quality might often sound dreary
- May not pair with your amp circuitry
Conclusion: The Best 5751 Tube Is…
All four 5751 preamp tubes-two of Tung-Sol and one each from JJ Electronics and Sovtek-meet the criteria for reducing the gain factor.
While the JJ Electronics amp tube is a tad pricey (see our JJ 5751 review above), the rest tend to be supremely affordable and quite versatile.
Overall, the JJ 5751 tube is the best 5751 tube available on the market at the moment.