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Feline Futterman OTL Amp

Hi all ! , It’s not a new amp , it’s my first tube OTL amp , that I designed an built back in 2004 .

It’s a Futterman topology ( more specifically it’s an iverted Futterman , also known as Technics variation ) with the PL36 tube . The amp is been working till 2011 when my new Circlotron OTL amp took it’s place ! . More information about the two amps you can find in the following thread … http://www.diyaudio.com/forums/tubes-valves/200823-my-new-circlotron-otl-tube-power-amp.html .

In September 2014 I decided to redesign and rebuild the amp , the whole process took me almost two years due to many reasons , but finally the amp is playing and it sounds pretty good ! .

The circuit design is similar in the two cases ( before and after the redesign - rebuild ) , but with different tubes and with all the knowledge that I earn over those years . So the first stage is a differential amp with the ECC83 tube , carefully designed for low distortion , the second stage is a common cathode stage with the EF184 tube and the output stage as I said before , is an Inverted Futterman topology with one EL84 drives twelve PL36 tubes ( triode strapped ) !! .
 
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This is a picture of the amp before starting the whole process of the redesign ! .
 

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