Harma Valves / ECC83/7025-HARMA DR250

ECC83/7025-HARMA DR250 ECC83/7025-HARMA DR250 Click on image(s) above to view larger
Select Test Options
  • Factory Tested
  • Balanced (Triodes)

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

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.
The Harma 7025 STR DR250 is a close sounding recreation of the famous USA made 7025 valve.

The valve supplies a tight and deep bottom end sound with excellent midrange clarity. The top end has a sparkling clean sound and provides the right amount of top end focus to make any vintage amp sing.

These are great in old silver faced Fender amplifiers as the valve has a number of design features that make it ideal in combo applications.

The valve has a very rigid internal construction with supported short anode plates; this combined with this 22 mm thick glass envelope make this valve very low in microphonics. The valve also provides very low noise which makes it an excellent choice
In modern made and vintage amplifiers. It has a nice early harmonic crunch when pushed and retains that classic Fender style sparkle.

These selected valves all measure up to the 7025 specification and can be fitted in the most demanding positions of all amplifiers. Each part of the triode will have a rating of above 250 on our rating system and are the first choice for those of you who want clarity and gain.

We offer two options:
1) Selected & Drive Tested
2) Balanced -matched triode sections for Phase splitter, Audio & Tube microphones

All Harma preamp valves are Dynamically Drive tested under real working condition have passed the following tests:

Gain (db) Drive Tested)
Transconductance (gm) Drive Tested
Output Drive Tested
Noise 1 (signal to noise)
Noise 2 (Aural)
Microphonics Test 1(Ambient)
Microphonic Test 2 (Shock)
Cathode Test
Grid Leakage Test



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