Blog - 12AX7

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Tungsol Electro Harmonix and Sovtek 12AX7 Valve Heater Glow

Everyone that loves the look of Glowing shiny valves sitting on a high end Hi Fi amp or visible behind a Guitar Valve amp Head will have mixed reactions regarding the new Generation Preamp tubes being produced from the Russian Factories. To the Dismay of the "we love the valve glow" fans they have modified most of the latest generation designs to improve Emissions efficiency which results in an all round better performing tube. The down side is a much tighter plate cage making it almost impossible to see that familiar red hot heater glowing from top, bottom and sometimes through the now vacant side holes.

We found on the Sovtek 12AX7LPS valve that you could not see any sign at all of any heater glow.  Some of the Electro harmonix valves are barely visible in darkened environment but again with the Tungsol valves we found it difficult to see the warm red heater glowing.

Manufacturers affected by not having a big bright heater glow are, Tungsol, Sovtek and Electro Harmonix preamp tubes.

So next time you invest in a brand new shiny pre amp tube for your beloved gear please note that a lack of glow is not indicative of a tube that is not working correctly but actually is likely to be a new generation valve.

Amp Valve Balanced

What is a Phase inverter Amp ValveThe pre amp valve that drives the power tubes in a valve amp is often referred to as the Phase Inverter (PI) or the Phase Splitter.  Its primary role is to drive the power tubes.  A common set up is to use a double Triode pre amp tube like [...]

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Amp Valves Tubes How often do I Replace Them

How often Do I need to replace my Valves ?This is a question that is commonly asked about both preamp valves like the common 12AX7 ECC83 and also power valves like the EL34, 6l6GC, EL84.  The answer is not definitive but hopefully the following comments and things to listen out and look for may be [...]

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The Voc Rock 12AX7 B High Grade Valve

The NEW Voc Rock 12AX7 BWe finally achieved it.  Our very own 12AX7 Pre amp valve released and ready to go.  These valves are sourced from one of the worlds biggest and most reputable tube manufacturers as High Grade Low Noise valves.  We then run them through our meticulous burn in and test procedures to [...]

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Tung-sol 12AX7 Review

Tung-sol 12AX7 Review The Tungsol 12AX7 is a high grade Russian valve. The valve is very well engineered and ruggedized using thick glass and firm internal supports. On test we very rarely see failures after burn in indicating good long term reliability. The gain factor of the valve is slightly [...]

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