EML 300BM+
Price range: $968.00 through $1,960.00
The 300BM+ is the mesh-plate version of EML’s classic 300B (new for 2026). The 300BM+ is designed to adhere to the original Western Electric specifications, with a similar bottle size and similar plate structure area. Like the original W.E., the EML 300BM+ has a 36W max dissipation rating (40W peak).
As with all the mesh-plate variants we expect an improvement in detail, air, and space. The 300BM+ is no exception. While it still retains a trace of the classic 300B euphony, it’s more neutral and open sounding in it’s presentation. The EML mesh-plate series in general have quickly become a house favorite at ET.
All Emission Labs tubes are inspected and tested in-house before shipment. All EML tubes are shipped in factory packaging, with factory test results, as well as our in-house test results.
EML 300BM+ Short Data:
Maximum Ratings
- Plate Voltage = 450VDC
- Plate Current = 100mA (Auto Bias)
- Plate Dissipation = 36W (continuous)
- Series Grid Resistance = 150K Fixed, 250K Auto
Typical Characteristics
- Filament, 5V – 1.3A
- Plate, 300V – 60mA
- Tc – 5.5mA/V
- Rp – 700Ω
- mu – 3.9
- Grid Voltage, -61V (AC.Fil), -58.5 (DC.Fil)
Please read below for more info regarding all of the 300B offerings from Emission Labs.
EML 300B comparison:
The EML 300B (standard) is designed to adhere to the original Western Electric specifications, with a similar bottle size and similar plate structure area. Like the original W.E., the EML 300B has a 36W max dissipation rating (40W peak). Sonically the EML 300B is very detailed, fast, and refined sounding. The highest frequencies are slightly burnished, and the classic “300B mid-bass” emphasis is present. In comparison the USA made W.E. has a more exaggerated mid-bass region and an even softer treble response, which provides a more euphonic overall character. While both tubes are cut from the same cloth and provide the “vivid” mid-range you want from a 300B, the EML is a bit more accurate sounding with a less colored presentation.
The 300B-XLM mesh-plate is a longer anode, bigger bottle, uprated version of the classic EML 300B. This is the mesh-plate equivalent to the 300B-XLS, and an improved version of EML’s classic 300BM, which has been in production since 2001. We’ve found that the XLM is simply the most detailed sounding of the lineup. Completely linear in its presentation, with no mid-bass emphasis, and fully extended “airy” highs. For those that find the typical 300B experience round and lackluster, these are a revelation. They’re also ideal in demanding amplifiers where a traditional 300B would be running right up against it’s max ratings. These tubes look and sound identical to EML’s original mesh plate 300BM, but with improved voltage and current handling, allowing them to be used interchangeably with the 300B XLS, up to 42W on the plate.
The 300B-XLS is a high power solid-plate 300B substitute, with a 55W plate dissipation rating. These tubes provide more headroom and a very articulate and muscular overall presentation. Many 300B SET users benefit greatly from the added headroom. Listeners with medium efficiency speakers, panels, and or full rangers love the ease at which these tubes play. They can free up dynamics and bass energy beyond that of a traditional 300B. They’re also ideal in amplifiers that push standard 300B’s right to their technical limit. Offering better reliability and longer life at extreme operating points.
It’s also worth mentioning that the JJ 300B has a lot of the same attributes as the EML 300B XLS. The JJ is slightly less detailed but again playing with lots of authority, bass energy, and good reliability at high power levels. This makes the JJ 300B an excellent choice at a lower price point.
In general it’s our observation that 300B choice very much tracks speaker efficiency. Many of the 300B users we encounter are playing their SET amps with modern “low to medium efficiency” speakers, and while they love the mid-range character of the 300B they’re missing dynamics, swing, liveliness, etc. These users tend to be really blown away by the 300B-XLS and the JJ 300B. In comparison we find that horn users start gravitating toward the traditional and mesh plate types. With that said, ultimately listening preference is the deciding factor. Soft/romantic vs dynamic/lively. Mesh plates combined with high efficiency speakers offering the best of both worlds. Please email or call us if you need help deciding on a 300B type.
Eurotubes is an official Emission Labs dealer. All EML tubes purchased through Eurotubes come with an automatic 1-Year (2,000hrs) warranty, and are eligible for the factory registered 5-year warranty.