EL84/E84L-HARMA CRYO BURST TESTED Click on image(s) above to view larger

All prices contained on this page are exclusive of VAT. This is currently charged at 20% and is payable by the UK only.

Harma Deep Cryogenic treated valves offers improvements to the sonic character of the valves and results in sound characteristics only normally found in very expensive NOS valves such as Mullards. The process involves taking the vacuum tubes and freezing them down to -312 Fahrenheit and soaking these for a minimum of 12 hours. Then the temperature is held at this low level for 24 hours. The vacuum tubes are then slowly brought up to normal levels over the next 12 hours.

Metals respond very well to deep cryogenic process. The reasons are as follows, during the cooling or solidification phase of the manufacturing process, molecules are trapped in a haphazard pattern. This is down to stress caused in the bending and welding of the anode plate material. This random placement causes obstacles for electrons and when encountered this interference can cause noise, slow down electron flow and sound deterioration affecting the quality of the sound of the vacuum tube. .

At very cold temperatures (below -312 Fahrenheit), the molecules will align in a more uniform, compact structure through the removal of kinetic energy. When the material is returned to ambient temperature, this new uniform, compact pattern is maintained, Thus changing the structure of the nickel permanently. This process makes a permanent change and the benefits do not deteriorate over time or upon return to operating temperature, it changes the whole way the vacuum tube performs.

The biggest benefits I have found have been a dramatic improvement in the sound quality. The bass response has been clearer with reduction in microphonics and clear more transparent highs. Cryogenic treatment has now become a way for a modern valve to produce a sound quality that approaches the iconic originals.
The Harma E84L Burst Tested on the tester designed for Brian May

This valve is the specially treated cryogenic version of our E84L. The Cryo version offers more clarity and treble detail than the standard item. The bass response is also clearer and has greater depth and punch. The Real Benefit of this valve is that it remains warm and smooth even under the heaviest saturation providing the maximum clean headroom out of any current EL84

This valve is our recommendation for high end audio amplifiers due its musical transparency.

The Harma E84L Bust Tested Cryo is a high quality special application military valve which has a number of unique features. The valve is electrically rated at having a plate dissipation of 14 watts, which is higher than any other EL84, all others being rated at 12 watts.

The valve has a mechanical rugged construction and thick glass as they were originally designed to be immune to shock and vibration as they were designed for military applications

These features reduce microphonics and rattle in all guitar combos. The valves also use high grade filament isolation so even after long periods of use the filament will not degrade and a triple supported getter and thick grade mica. The valve has a coated anode which makes it stable and able to stand high voltages.

No previous or current EL84 was made to this specification
This will explain why over the years this valve has given exceptional performance in the most demanding circumstances.

The valve produces the maximum clean headroom out of any current EL84 providing the best clean sound by far in guitar applications. The bass is really deep and solid with excellent balance and no hardness. In guitar applications it offers late breakup and displays a rich warm overdrive sound when distorted which is not matched by any current made EL84.

In Audio applications this valve is very difficult to beat without spending vast sums of money on new old Stock items. The valve has a clarity and musical performance which is enjoyable and engaging and will upgrade the modern and Vintage High end audio amplifiers such as Beard, Audio Note and Leak.

This is the specially burst tested and Cryo treated version of the Harma E84L which is tested on the rig built for Brian May for the ultimate reliability. They undergo our own unique real world burst testing. The burst testing process involves a series of varying timed electrical signal bursts. This runs the valves under the same stress conditions that they will meet in your amplifier. This gives you the most through tested valve available anywhere in the world.

This valve is a specially treated cryogenic version offers more clarity and treble detail than the standard item. The bass response is also clearer and has greater depth. This valve is our recommendation for high end audio amplifiers due its musical transparency.



Facebook Twitter Follow us on Instagram