Which 12ax7 sounds best

The best part is that the manufacturer tested every tube, and upon getting the tubes, you can see the test readings written on the box. If your amp has a natural drive and sounds extremely quiet, then you can say goodbye to those. Upon installing this tube to an amp, the amp will now have a very clear and clean output with minimal drive and distortion even at high volumes.

When using this tube on a Hi-Fi amp, it is immediately noticeable that this tube will give off a very clear and detailed sound. But a drawback for some people is the noise this tube brings. Overall, an audiophile liking this tube will rely on their preference. If your preference is a very natural sounding tube, then with all means you can get worth out of this tube.

This tube will also last up to 10 years with proper use and care. The JJ 12AX7 brings a well-balanced tone that will give your signal a high presence boost. The JJ 12AX7 works exceptionally well with guitar amplification as this tube will give your guitar tone more color and more detail.

And this tube will also give out an excellent overdriven tone with very distinct bass and mids. With guitar, this tube will work well with Jazz, Rock, Metal, and Blues. Moving on with our main topic, how will this work with Hi-Fi? This tube produces slightly more bite than a typical 12AX7 does.

This results in added tonal warmth and linearity, making for clear transitions between the many frequencies of an electric guitar. Electro-Harmonix is responsible for some of the best-known effects pedals ever made. Their attention to detail when it comes to tone and sound is industry-leading. This pair of 12AX7 tubes sound as good as you would expect them to, coming from such a well-known manufacturer. The pre-amp tubes are matched for gain and power, and the built in spiraled filament reduces the unwanted noise associated with pre-amp tubes.

This valve has a rigid internal construction and thick glass casing. It breaks up easily and is well suited to both modern and vintage high-gain guitar amps. There is a detail which these tubes provide, probably down the low microphonic output.

This feature really allows you to hear the tonal qualities of the amp without the annoyance of unwanted hum or buzz. Most tube based guitar and bass amplifiers utilize the 12AX7 pre-amp tubes in their design.

Many amps use multiple 12AX7s. They are without a doubt the first choice for tube amplifiers due to their low noise characteristics and the high gain output they provide. These tubes were originally developed as a replacement for the 6SL7 which produced problematic microphonic noise and were bulkier in design.

Even with all of the modern developments in audio technology, the 12AX7s are still used in most amps as they provide the sound which we as guitarists have become so familiar with. The fact that over two million 12AX7s are produced annually proves that they are still a hugely important component of guitar and bass amplification.

When you are looking for the best 12AX7 tubes, a term which may keep appearing is microphonics. This refers to issues which arise with an amplifier. A separate filament transformer was used on the switching box to simultaneously heat all six comparison tube filaments without overheating the amplifier's power transformer. A shielded cable was constructed to plug into the amplifier's V1 socket and transfer its pin 1, 2, 3, 6, 7 and 8 connections to one tube socket at a time in the switching box.

Listening tests were then conducted while playing guitar and switching between the tubes at various amplifier control settings to come up with tonal descriptions for each tube. Kurt began playing guitar at the age of nine in Kalamazoo, Michigan. He is a guitar DIY'er and tube amplifier designer who enjoys helping other musicians along in the endless pursuit of tone. Skip to main content. Gain rated at 7. Gain rated at 5. Gain rated at 4. Gain rated at 3. Gain rated at 2. Schematic of the preamp circuit used for 12AX7 comparison tests.

Note that the information presented in this article is for reference purposes only. Amplified Parts makes no claims, promises, or guarantees about the accuracy, completeness, or adequacy of the contents of this article, and expressly disclaims liability for errors or omissions on the part of the author.

As if the sound could not unleash and dispense the haze. This tube will be good to tame some excessively bright equipment but it is not synonymous with transparency. In mono applications this will be no issue, however.

An excellent choice for high fidelity applications. During this review we usually played the music at fairly high volumes which highlighted one of the vacuum tube issues: the microphony. The SPL Vitalizer uses quite a clever solution to keep the tubes stay put — each tube is capped with a rubber ring that is a part of metal piece anchored by a bolt in the printed circuit board. The problem is that with every change of the tube one has to dismantle the Vitalizer as the bolt can only be accessed from the bottom of the device.

Because during the review we kept the tubes in the Vitalizer without this clamping to enable easy swapping of the tubes, the microphony developed in full. We tried to use trusted silicone rings available from many sources in different positions on the tubes and we used single pieces or doubled and tripled them.

The result was similar to what you can expect with any soft and heavy dampening device — the transients became smeared and the sound lost articulation. This is because the rubber or silicone mass takes the mechanical energy from the tube or environment just to return it back a fraction of second later.

The microphony is removed, the temporal precicion is impaired. Robert Herbelin, who runs the HAL, does a different thing. Each pad holds a specially formulated polymer O-ring against the tube glass. The whole system does not store any energy and the vibrations of the tube are dissipated through the titanium ring. And the UltraSonic Rxs really worked wonders. For example, the rolling big drum was just a thundering massive wall of sound with the silicone rings in place.

With the USRxDI the resolution stepped up several levels, each stroke of the mallet became delineated and the bass stopped masking other instruments of the symphony orchestra, thus making the music sound clearer and more transparent, yet digging deep, possibly deeper than before. We could also play dB louder without any congestion or constraints. Similarly the acoustic double-bass became highly contoured and more clearly locked within the soundstage, but rather than sounding too hi-fi it sounded wonderfully natural.

The tubes reacted quite sensitively to where the UltraSonic Rx Damping Instruments were positioned on the glass. Some experimentation will be needed to find the sweet spot in your application.

There will be none. Still, this test can give a bit of guidance of what to expect from the tubes of today and that it is not necessary to spend a fortune for legendary vacuum tubes on ebay when some fine sounding equivalents can be had from contemporary sources. Special edition reviews. The best 12AX7 tubes for almost no money.

PW The best 12AX7 tubes for almost no money For a newcomer it is not easy to navigate among NOS tubes that are available through Ebay or similar sites. Methodology Finding the optimum working conditions for each tube was a challenge — it was not clear what these optimum points were as each tube was pretty unique.

The sound is as if gold-dusted but it is not really warm. This combination makes a wonderful appearance for violins that are silky and smooth, yet detailed and real. During the pizzicato the tension of the string is a very palpable experience. The sound of the orchestra is slightly homogenized and its dynamics is a bit restrained — more openness and explosiveness would be appropriate. The body of the double-bass is more felt than heard.

Transient is OK, followed by a soft thump which makes the sound slower and less defined despite the bass weight is quite good.