• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

EF80 push EL153, DIY with a picture tells a story.

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EF80 driving EL153, DIY with a picture tells a story.

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Telefunken's EL153 get our hands there is a feeling of love. 40W power consumption of the anode than his sibling "EL156" summoned up the courage, but has a lower resistance, capacitance between smaller. EF800 EF80 is the long-life models, more precision and longevity. With the EL153, can be described as heroic beauty, good match.

EL153 \ EF80 is a very good performance of vacuum tube, many people can not properly use, resulting in the illusion of high frequency of inappropriate audio use. This article is to teach you how to design, diy, out of a high quality tube amp. And those who disseminate high-frequency tube audio is not well people use the rumor nowhere to hide.

Detailed test results later in this article.
 
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Power supply design is the most important, reduce the AC ripple in the same time, but also to reduce the power resonance amplitude. Here we are using bile rectifier, only to reduce the amplitude of the resonant power to raise more quality sound.

Figure borrowed a transistor as rectifier participate simulation, the actual use of the use of 3DG4, in order to sufficiently rectified current. Double choke design will ripple reduced to -70db or more.
 
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C4 out of the upper end of the simulation ripple. Small hum ripple ripple is less than 0.3mvRMS, a large low-frequency resonant power supply ripple ripple is less than 1mvRMS. If not gall rectified, this 8hz will ripple around the resonant power up 200-400mv, overall sound quality deterioration will be the culprit.
 
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Use the anode screen consumption 37.5w, plus screen grid power, it should not be less than 40w. EL153 is not expected to be too cool, the surface temperature should be close to 200 degrees Celsius.

According to the simulation results, a high-quality, low ripple power supply circuit came out.
 
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el153 via the output transformer as a load, via the load curve can be seen EL153 anode output voltage p-p550v, via 16.7v transformer turns ratio, P-P33V about theoretical output voltage. That is 11.67vRMS. In this case the theoretical maximum output power RMS = 17w. 14.83v given value for the calculation software standard tolerance. Transformer design efficiency of about 87%, in theory, the circuit output 12-14wRMS without any problems. 90 F, the full power output of the test results, 8 ohms RMS ended output voltage up to 12v, the output 11vRMS still very high fidelity. Output Power Output RMS12v time is 18w.
With simulation, circuit came out. Circuit in the device values are estimated values, the specific use of the device value will be adjusted according to the test after completion.
 
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