Impedans of trafo for EL504 inSE

[Ryssen]

What impedans should the trafo be for triodmode.Is 2,5k to low?

 

[Fuling]

2,5k is a bit high, I used something like 1,3k in my prototype PL504 SE triode amp.

 

[Ryssen]

Ok,hello "Fuling"🙂 .What if I use 2,5K is the "only"side effect less outputpower,or are there more?🙄

 

[Fuling]

It will probably work just fine, as long as the transformer can handle ~100mA DC. EL504 seems to work best at low voltage and high current.

 

[Ryssen]

I have 2 tubes by the number of"76" can these be used as a driver for the El504,if I use the 504 at 80mA 175v.The 76 have a ampl.faktor of 13.8, does that mean that if i send 2v in I get 27,6 out?If its to low I ment to use a 6DJ8🙄

 

[Ryssen]

What driver did you use?Any feedback? Do you have a schema?🙄

 

[Fuling]

If I remember correctly I used PC86 as drivers, loaded with Hammond 156C chokes. The OPT´s was my own design that involved 25% cathode feedback.
The amp put out a couple of watts and sounded quite darn good, but for various reasons it never got further that the prototype stage. No schematic available.

 

[edonion]

This is my PL504 push-pull amplifier.
I have good results with 750 Ohms Plate to Plate.
http://edonion.com/documents/EdonionSpeedy.pdf

You can see it here
Transformadores

I hope you enjoy it. Sounds very good

 

[pilovis]

The correct value for PL504 is 800 ohm.

 

[edonion]

The correct value for PL504 is 800 ohm.

I can not be as accurate. Since my components have 5% tolerance and the impedance of a speaker is not a constant.
The only thing I can say is that the amplifier is constructed as the above scheme and it works flawlessly.

 

[pilovis]

I can not be as accurate. Since my components have 5% tolerance and the impedance of a speaker is not a constant.
The only thing I can say is that the amplifier is constructed as the above scheme and it works flawlessly.

Any value between 700 to 850 ohm is OK.