• 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.

My new Circlotron OTL tube power Amp.

Really impressive performance, Dimitris!

Now I think it's time for you to share your schematics :)!

Best regards!
Thank you very much Kay Pirinha , this circuit is the best that I ever build and design , so I would like to keep it away from the "limelight " , but I will share the circuit of my old line preamplifier , it's a simple circuit and performs well .
 

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sounds nice and love the reuse of the old nec reciever for the Jackal preamp. You seem to use brute strength capacitance for the Jackal power supply, do you prefer this approach to CLC mkp style psu we see in many tube preamps?


Sorry for the late answer , didn't see it before , yes I prefer the CRCRC filters than the CLC , I don't like very much the sound of coils in the power supply , of course they have greater ripple reduction ( -40dB / decade filters ) , but using many CRC filters you get a really clean and nice sound ! .As for the MKP caps they are bulky and usualy expensive ! .
 
BTW this preamp almost not "exist" now , I redesigned - reconstructed it from the beginning , and the result is more clean and detailed sound and very good high frequency response !! .



One PCC85 ( LTP input stage ) , one PC92 ( common cathode stage ) and one EF184 ( buffer ) in each channel



Output impedance < 50 Ohm

820KHZ ( -3dB ) high frequency response !! .
 

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I know lampizator use a mix of crc electrolytic and clc mkp. Some say that crc has better bass. I use electrolytic on my tube pres but will try CLC mkp as well.
This pre must have a lot of gain. What is the LTP for, why not a common cathode and buffer? Is EF184 in triode mode?
 
Hello sir Dimitris, also hello to the people here as well.
I just got my hands on two EF183 , and I would like to build a single ended, class A, preamplifier with them. can you help me out ?. Its my first time with " tubes" and I would really like to learn about them , and find out how they sound. I did many BJT, Mosfet amplifiers in the past, but never Tubes.
I only own 2 of them( but still it would be a nice project to use them somehow)
I tought I can use them like a class A single ended ( like the schematics with just one transistor ) pre-amplifier. I dont know , to use them as pentode or wire them as triode.
Also Voltage? ( I tought about 100-150v would be enogh ?) Some schematics, advice, would be really appreciated. Greetings!.
 
Hello xBruno , EF183 ia a variable transconductance tube, so it's not intended for Hi Fi amplification , I use it only as a buffer ( cathode follower ) this was back in 2011, now I don't use this tube at all , if you want to build a preamp find two EF184 and triode connect them in a common cathode circuit , also 100 - 150 V is low for a tube preamp , you will need 280 - 300 V , but with such circuit you will have high output impedance, so its better to use a buffer stage after the EF184 .