Harma Valves / 5881 HARMA-MESA BOOGIE 400 PLUS SET

5881 HARMA-MESA BOOGIE 400 PLUS SET Click on image(s) above to view larger

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A test report is available click here to view

Harma valves consist of a selected range of valves that are chosen after meeting stringent standards for sound quality and reliability. These valves are sourced from current production as well as some of the finest Nos valves available. Unlike our competitors no Harma valves, past or present has been made in China. Harma valves represent the finest available items of their type available.

Harma valves are tested using a range of custom designed and built test rigs which are unique to Watford valves.These unique tests are not offered by any other valve supplier in the world.

All Harma pre amp valves undergo the drive rating system; the valve undergoes a series of through tests under full operational conditions. This involves a controlled burn in process to ensure perfect stability and correct ageing. A shock and vibration test, microphoney, hum, and a balance and symmetry test.

All Harma output valves undergo our own unique real world burst testing. No other supplier tests valves this way. 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 especially when overdriven. All out put valves are then dual matched by us on anode current and gain. This will ensure that you get the best selected valves available anywhere in the world.
Special Offer 10% Discount

This is a specially selected matched set of 12 5881 valve for owners of the Mesa Boogie 400 plus bass head.This is exactly the same valve as boogie used in production of this amp which Boogie branded the STR 425.
These are all tested and selected by us in a converted Mesa 400 plus amplifier specially designed to test these valves.

The Harma 5881 is the button based Russian military valve is the same valve which powered the Marshall and Mesa Boogie amps (STR 425) in the late eighties. This valve has bullet proof reliability and proven track record over decades of use in Russian military applications.

This valve was designed to withstand 3G as it was used in the servo motors of Russian fighter Jets. The valves are made with high quality military grade plate material for extended life in the most serve working conditions. Therefore have a reputation which is second to none in terms of clarity and reliability. These valves are of a much higher specification than current manufactured 5881 and each of these valves also has the Russian government stamp of approval for military applications.

So when used in Guitar amplifier applications this valve is vibration and rattle free and will give many years of excellent service.

Indeed I have seen many 400 plus which date from 1994-1996 which still have the original valves. This is simply astounding as many modern 6L6GC valves will get no where near this life span.
This is why Mesa and Marshall used this valve to power their designs thought the 1980's and 1990's.

So as I own several Mesa 400 plus bass heads I fully understand the pain involved in revalving this classic bass amp and maintaining your sound without the need for a second mortgage.

We have therefore matched special sets of 12 of these 5881 with identical current draw and output gain. They have also been tested for hum and microphonics all within the parameters of our own Boogie 400 plus. With these original Military 5881 we can maintain your sound for gig after gig.

The set consists of 12 identically matched Harma 5881.

Here is Guitarist Paul Bacon email on fitting the Harma 5881

"I just want to say how pleased I am with the Harma 5881 valves.
I have had problems with the Mesa branded valves ever since I bought my Mesa Express 5:50 Amp. All the Mesa branded STR440 valves developed a rattle and added an annoying harmonic hum to the amplified guitar sound after a short time.
I replaced the Mesa valves each time but the problem would repeat.

I spoke to Watford valves who were very helpful, and suggested some Harma 5881 valves as a replacement.
I have used the new Harma 5881 valves in my amp for many months now and the amp remains free of any tube rattle and harmonic interference. ****Problem solved.****"

Thank you

Paul Bacon



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