In turn, the value of C3 will be equal to uF for a 1 Hz cut-off frequency. A single EL84 was used in low-cost equipment, and a push—pull pair for lower distortion and higher power. Placing the value of 15KOhm to the formula for low cut off filter capacitor calculation gives us value of C4 equal to 10uF. Page 1 of 1. Other equivalent tubes are the and A , [4] [5] an extended-ratings version of the tube for industrial applications, E84L long life, professional version with more than hours expected lifetime and the directly equivalent 6P14P Cyrillic: When we come to calculate the gain, we find that the anode characteristic begins to curve as we reach its intersection with the load line. The EL84 is smaller and more sensitive than the octal 6V6 that was widely used around the world until the s.

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I have a problem using a semi-power tube in this manner because it isn’t warranted. Articles needing additional references from June All articles needing additional references All articles with unsourced statements Articles with unsourced statements from August Articles with unsourced statements from March Articles containing potentially dated statements from All articles containing potentially dated statements.

The time now is There are ways to work around it such as negative feedback, but good amp design is much better than such a band-aid.

I’m getting a bit ahead of myself. Retrieved 23 May R5 is chosen either by a detailed perusal of the datasheet, or by observing that, in general, the anode current is a fixed ratio of G2 current. Of course, one wattage level is in pentode mode and another is in triode. EL84 pentode as driver Posted: If petode needed to go to class A2 then for sure it will be inadequate.


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Also plate impedance 38k ohms approx for the pentode mode 2k ohms in the triode mode the result the amplifier is more dampened in the triode mode closer to a solid state amplifier sound then in the pentode mode So triode mode not only drops power it reduce overshoot due to inductance, capactance and other effects relative to the speaker used over all psntode won’t sound as bright as the pentode mode.

The grid resistor of the power stage needs to be at least K penhode cope with this.

Sat Jan 28, 5: Mon Jan 30, 3: Somehow, the sounds of these breadboarded amps are excellent! But in A1 it works fine. It could also make a good LTP splitter because its increased power makes possible the driving of K ohm grid resistors in the power stage.

Triode mode also has better low frequency response Something I just started to look into is the effect of the transformer on frequency response. I’ve wondered about using “power” tubes as preamp tubes for a while. I do however feel that the thoughts relating to using something like a 12AX7 as a driver for a power tube are not entirely correct.

Now let’s calculate value of C4 in order to hold second grid at AC ground potential. The increased power might be helpful in this region.


I used the s, because I originally designed most of the amps with 6SL7s and 12SL7s in mind and they have nearly the same characteristics as the The only reason to do this is to run the power stage pebtode class A2.

The Sovtek EL84 is often sold under their own brand name by other well-known electric guitar and guitar amplifier manufacturers – such as Fender or Mesa Boogie.

It is used in the power output stages of audio amplifiers, most commonly now in guitar amplifiersbut originally in radios. While not necessarily a true “military version” of the tube in fact it is more comparable to the6P14P-EVs are known for their low noise and durability.

Fri Feb 03, pentodee If the 2A3 has a positive grid throughout the whole cycle, you’ve successfully built a space heater. Mon Jan 30, 8: And these cap’s will soak some current.

Bugera EL Premium Power Pentode Amplifier Tube EL B&H

The restrictions the output transformer places on a tube amp theoretically make it counterproductive to hi-fi. Generally, I agree with most of the previous posts and the concepts.

It is perfectly valid to treat the anode curve as a straight line, and to project this line onto our load line in order to find the gain.