Philips EL6411/01 amplifier

[shrad]

This is a multitap from 16V to 170V output in 10 steps if I recall well enough, and 16 and 32 volt taps were good for 8 ohm arrangements like you would do for a 8 or 16 ohm stack

when I last tried it I came to the conclusion that everything before the phase splitter was good to throw, and I did not have a go at rebuilding a complete preamp and tone stack

I have another plug and play technique to have a direct replacement for everything before the output tubes but this is still in the bench... this is an idea I started two years ago and I finally found a good combination of class D amp and interstage transformer to be able to put it in front of most PA amps that need up to 60v swing on the output tubes and adjust amplitude by simply varying gain pot of the class D amp module

it will be the object of a small thread once it will be done (I think my current guitar rebuild of a geloso would fit well)

 

[mississippi]

Here a list how to look for different output impedanties for the EL6411.

 

[shrad]

very interesting thanks a lot! I usually derive impedance from delta V between two windings and squared volt ratio from the B+, et caetera (table required but usually a quick calc is good enough to choose a decent tap, and fiddle with nearest ones if Pout is not as expected)

 

[Bjornganzer]

Hello! Did anyone try the el 6411 as a microphone preamp? Would this be possible to give vocals a touch of tube sound??

 

[OldHector]

If you are looking for something to fit that role, then a Tandberg 62 or 64 is a good starting point.

 

[Bjornganzer]

Hello, does anyone know the minimum ohm on this phillips??

 

[56085]

I'm not sure what it is you ask. If it is about the input impedance for microphone, than it's 1 Meg. If it's about the speaker output, than it's 3 Ohm (see post #42).

https://nvhrbiblio.nl/schema/Philips_EL6411.pdf

https://nvhrbiblio.nl/schema/Philips_EL6411-07.pdf