ECL80-Amp from Andreas Kirschner

[bobo1on1]

I just stumbled across this little ECL80 amp, it looks fun to build for a first project.

An externally hosted image should be here but it was not working when we last tested it.

However the output power seems extremely low to me, as the transformer he is using only has an input impedance of 400 ohms!
Here is the transformer datasheet.
Now I happen to have two of those transformers just sitting here on my desk collecting dust, so I might as well use them as I can buy ECL80's for €2,25 a piece but I hope it has enough power to drive more than just a pair of headphones.

Any comments?

 

[moamps]

Hi,

100V transformers usually don't have a gap in the core, which is needed to handle DC anode current in SE designs. Besides their frequency response usually doesn't meet HI-FI standards.

Regards,
Milan

 

[bobo1on1]

Although I didn't measure the frequency response of these transformers, they do not sound bad at all when connected to a normal SS amp.
I think they should be able to handle at least 2 watts which comes down to about 60-65 mA, DC resistance is 485 ohms on the primary.

According to the datasheet, the pentode section of the ECL80 can only handle 17,5 mA but with a 400 ohm transformer that's only 60 mW or so?