Power appears only to only around 3.5W by a method of normal grid reaching the ground when I say where there is difficulty of a SV811-3 amplifier. The voltage of 160V peak to peak being necessary for the input and high pressure more than 500V are necessary.
It is for the voltage of around 700V to be necessary for high pressure by a normal circuit. Power supply environment similar to 211 and 845 will be necessary in this.
I have to throw over Grid to a domain of a plus to get electricity more than 3.5W. Therefore it is a transformer drive used to the public that came out. I think that the grid voltage of high pressure is easily provided by how to use. I was able to get 150V peak to peak here.
Because it is diversion from a 300B amplifier, high pressure is low with 450V, but I seem to be the minimum voltage, but it is a place wanting 500V here.
But if would like to get one like this one please use more than 500V DC much better.around 600~700V is best.
Is a good amplifier done?
The amplifier which I assembled with an experiment becomes another several of them. There was the plan to make an amplifier of an inter-stage drive someday, but department time suffered very much till I made it like an output transformer because I was expensive.
I used a cheap transformer of Tamura for an inter-stage this time. It is a European tubes of mini watts which it used ECL82 for in the first grade. I prepared latest Svellana 6BM8. A drive is two steps of direct coupling. Five pole departments 3 has it as pole combination. An inter-stage transformer is 5K: It is a transformer of 5K.
I make a second side of an inter-stage transformer reverse connection concerning an output transformer and prevent an oscillation.
Grid bias is -70V. Because 0.06V occur in this at both ends of ten 立, I want to do it to around 70mA in coordination with bias because 60mA are plate electric currents. I talk with capacity of a power supply transformer here, and please decide a moderate plate electric current. I think that around 80mA are good.
If do you have good big power transformer will you try more than 100mA plate currents into SV811-3 single ended
amplifier. probably you can get gggggooood sound from your speaker system.SV811-3 are still cheap and you can get
around USD 70 pair easly.why still cheap because I guess it's difficult to use.
Let's say the most important thing
Damping Factor is around 1.5 with a nude characteristic. I think that a low level and the sound that is easy to be tiring that cracking down on grieves at in a high level are provided.
I think that I am easy to come to listen because DF stops to around 4 when 6dB can lack in NFB from 3dB to put up DF here.
I recommend that I test various vacuum tubes to a driver tubes.
I think that it is the vacuum tube that I hear a good sound than 300B, but there is a good point to a non NFB amplifier of 300B and 2A3 as such. In addition,
I think that I can use 211 and 845 by this circuit. I think that even the +B voltage of 500V can get power more than 15W.
This valve is not Svetlana original valves.Svetlana orderd to other company in russia.this is real history of SV811-3 Audio Valves.
I'm still using this amp in 2023. The transformer is Toei OPT-20S, but this transformer is a highlight core.
It has a very good ringing sound. Although it is a band type transformer, its specs imitate the TANGO U-808. The characteristics are almost the same.
The driver is one 5687, and it is a three-stage amplifier. I feel that the sound is good, especially the low range.Further modification is necessary
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Shishido's Circuit Diagrams of Amplifiers