Hi there again. I got an itch to use my stored Telefunken ef804s tubes in a mic pre. I will re-use chassi and supply from my planar v72 pre: The planar v72 from scratch
Im building it with parts at hand, so some mods is unavoidable .
The idea is to use the ef804s as the input tube and use the classic and probably the best feedback arrangement from the v76 design. The second tube is changed to half a 6n6p, wich use a resistor instead of a the original anode choke.
In between input and output stage is HP och LP filter. I dont need a shitload of gain so the last stage is cathode follower 6n6p + LL1671se. It drives the transformer pretty much flat into 30-40Khz region.
The goal is stability, low THD and great bandwith.
I will also use my handwound 1:8 IPT: The Mad Science Challange -DIY MIC IPT
Im building it with parts at hand, so some mods is unavoidable .
The idea is to use the ef804s as the input tube and use the classic and probably the best feedback arrangement from the v76 design. The second tube is changed to half a 6n6p, wich use a resistor instead of a the original anode choke.
In between input and output stage is HP och LP filter. I dont need a shitload of gain so the last stage is cathode follower 6n6p + LL1671se. It drives the transformer pretty much flat into 30-40Khz region.
The goal is stability, low THD and great bandwith.
I will also use my handwound 1:8 IPT: The Mad Science Challange -DIY MIC IPT
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