Tube Amp Doctor - 7025WA Highgrade - Preamplifier Tube
Delivers full gain with smooth top end - low noise
The TAD 7025 WA delivers full gain with smooth top end. No microphony issues even with the most sensitive preamps. The 7025 WA supports a fat midrange and creates a bold tone with lots of harmonics. Played clean, the TAD 7025 WA delivers a warm liquid tone which is very responsive to dynamic playing. Overdriven, the 7025 WA provides lots of sustain with well defined mid-range punch.
- recommended choice for most demanding guitar amp input/V1 stages
- extremly low microphony selected for most sensitive applications
- smooth top end
- full gain
- fat mid range
- tight low end
- outstanding low microphony
- low noise
- balanced systems
- triple mica construction
- replaces: 12AX7, 12AX7A/WA/WB/WC, ECC83, 7025, SPAX7-A
We recommend the RT080 TAD 7025WA as Inputtube for guitaramplifiers like Diezel ("Pit Spezial"), Blackstar, Brunetti, ENGL, Fender, Marshall, Mese Boogie, Orange etc.
The TAD HIGHGRADE Selection is especially recommended for use with demanding input stages (V1) and for all applications demanding the best selection for extremely low microphony 7025 / ECC83 / 12AX7A type tubes.
For regular applications the RT008 TAD ECC83 WA Selected can be used with the same sound and gain structure.
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
HIGHGRADE SELECTION - But only those tubes which pass these tests best are labeled Highgrades.
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.
TAD Premium Selected/Highgrade tubes are guaranteed for a period of 6 months (according to terms of warranties) for the quality criteria mentioned above.
- Voltage (AC or DC) - 12.6V +/- 1.0 (Series), 6.3 +/- 0.5 (Parallel)
- Current - 0.15(Series), 0.3 (Parallel)
Heating - Indirect
Cathode-to-heater potential, max - 150V
Direct interelectrode capacitances, max***
- Grid to plate - 1.8pF
- Grid to cathode - 2.0pF
- Grid to heater - 2.0pF
- Plate to cathode - 2.1pF
- Operating position - Any
- Base - E9-1, small buton 9-pin
- Dimensions - 58mm(height), 51mm(seated height), 22.5mm(diameter)
- Cooling - Conventional
- Approximate net weight - 13g
AF Power Amplifier
- DC plate voltage - 330V
- Positive DC grid voltage - 0V
- Negative DC grid voltage - -55V
- DC cathode current - 8mA
- Plate dissipation - 1.2W
- Bulb temperature (surface hottest point) - 160 degrees celcius