The HIGHGRADE Selection is the tip-of-the-top quality at the lowest noise (microphony, hum, hiss) level. Tipically only 0,5-2% out of the whole production of this tube meet the HIGHGRADE requirements.
NOTE: due to extreme demanding TAD-Selection criteria, the availability of this tube is limited. Please check the information about availability.
The TAD 7025 Highgrade can replace any ECC83, E83CC, ECC803S, 12AX7, 12AX7A, 12AX7M, 12AX7WA/WB/WC/LPS/EH, 5751, 7025, CV492 and CV4004
equivalent (same built) for MESA® SPAX7-A
DISTINCTION from RT093-HG 7025WB and RT030 7025 / E83CC HIGHGRADE:
Compared to the RT030 and RT093-HG, the RT010 has a smoother overall responce and better linearity qualifiying for natural clean tones and relaxed HiFi audio listening. The RT093-HG shows a little more edge in the high-mid range. As a result, it asserts itself tonally very well, which makes perfect sense in a band structure.
RT030 is emphasising the midrange a bit more and thus brings more warmth and a little less brilliance and depth definition than the RT010 and RT093-HG.
Due to their tonal structure the RT093-HG and the RT030 are even less prone to microphonics than the RT010 which qualifies these for use with extremely microphonic-critical amps.
The RT010 has the lowest floor noise of these 3 which might be espicially important for use in tube microphones and audio system input stages.
TAD PREMIUM Selected
Q: When does a preamp tube become a Premium Selected tube?
A: All preamp tubes labeled Premium Selected have passed the following tests:
- Low Noise Test
- Microphonic Test
- Gain Test
- Sonic Tests
- Shock Tests
- Listening Tests
- Balanced Output Test
But only those tubes which pass these tests best are labeled Highgrades.Typically this is approx. 3-10% from a production batch that qualifies for the HIGHGRADE rating from TAD.
Due to the very high selection requirements, this article is temporarily only available to a limited extent! Please note our shop-information on availability.
Matching and Selecting Options for Preamp Tubes
Matching in Pairs for preamp tubes means that two tubes show identical gain, hence, four characteristically identical systems.
This matching method includes our Balance-Selection. We highly recommend this matching method for hi-fi systems and all stereo applications.
TAD Premium Selected/Highgrade tubes are guaranteed for a period of 6 months (according to terms of warranties)
for the quality criteria mentioned above.