Hi Friends,
I'm a 17 years old tube enthusiast from Brazil, and this is my idea to use two XCL82 tubes to make a OTL design with negative feedback to drive headphones.
In the frist idea is drive only a Sennheiser HD580 headphone, but when I has simulated the pentode of XCL82 in TubeCad the Zout was around 86ohms ( 20mA, 200v Triode Connected, rk = 330ohm, gain is 0.71 ). A little lamp lighting in top of my head with the idea of put negative feedback in the amplifier and reduce the Zout to can drive 32ohm headphone.
I’m thinking to use the XCL82 because I can buy this in Brazil for US$1. This is a very popular tube.
But If I can’t drive some 32ohm headphones the idea is make a very stable and very good amp for mine headphone.
The schematic you can see below. Is C1 necessary? Is a good idea change the R1 to a CCS with transistors? I haven’t worked with it before.
[IMGDEAD]http://img178.imageshack.us/img178/7920/projetolh1.jpg[/IMGDEAD]
Best Regards,
Felipe Navarro
I'm a 17 years old tube enthusiast from Brazil, and this is my idea to use two XCL82 tubes to make a OTL design with negative feedback to drive headphones.
In the frist idea is drive only a Sennheiser HD580 headphone, but when I has simulated the pentode of XCL82 in TubeCad the Zout was around 86ohms ( 20mA, 200v Triode Connected, rk = 330ohm, gain is 0.71 ). A little lamp lighting in top of my head with the idea of put negative feedback in the amplifier and reduce the Zout to can drive 32ohm headphone.
I’m thinking to use the XCL82 because I can buy this in Brazil for US$1. This is a very popular tube.
But If I can’t drive some 32ohm headphones the idea is make a very stable and very good amp for mine headphone.
The schematic you can see below. Is C1 necessary? Is a good idea change the R1 to a CCS with transistors? I haven’t worked with it before.
[IMGDEAD]http://img178.imageshack.us/img178/7920/projetolh1.jpg[/IMGDEAD]
Best Regards,
Felipe Navarro