Hello.
A few years ago I built the PSE EF55 + 7W7 amplifier and played better in blind tests than the PSE 4P1L, however, before sales I did not make measurements so it is only a subjective feeling of the listeners. I did a simulation in the LTSpice program and the results are satisfactory, all the lamp characteristics downloaded from real lamps and not converted from pentode characteristics. Please change the file EF55 + 7W7.pdf to EF55 + 7W7.asc to do the simulation yourself and maybe change something for better.
Piotr
A few years ago I built the PSE EF55 + 7W7 amplifier and played better in blind tests than the PSE 4P1L, however, before sales I did not make measurements so it is only a subjective feeling of the listeners. I did a simulation in the LTSpice program and the results are satisfactory, all the lamp characteristics downloaded from real lamps and not converted from pentode characteristics. Please change the file EF55 + 7W7.pdf to EF55 + 7W7.asc to do the simulation yourself and maybe change something for better.
Piotr
Attachments
Hello.
Before you start commenting, see the simulation and tube models, I know that the EF55 is not a triode but a pentode just like 7W7. The diagram shows a triode because it is a triode amplifier (pentodes connected in a triode). In Poland we say "that thinking has a future". The diagram is correct and I cannot see the drawing because it is a diagram of how we want to be so correct ....
Piotr
Before you start commenting, see the simulation and tube models, I know that the EF55 is not a triode but a pentode just like 7W7. The diagram shows a triode because it is a triode amplifier (pentodes connected in a triode). In Poland we say "that thinking has a future". The diagram is correct and I cannot see the drawing because it is a diagram of how we want to be so correct ....
Piotr
Disipation on EF55 is 15.3W!!!
The tube has 10W+2W=12W disipation.
And Va max is 300V, You ran them un 350V. Not good for long life.
The tube has 10W+2W=12W disipation.
And Va max is 300V, You ran them un 350V. Not good for long life.
Hello.
Tube EF55 has distances between individual electrodes are 50% larger than EL84, the thickness of the wire is 2X greater than EL84 the same size of anode or cathode. The voltage limit for EL84 is 300V, power lilit 14W, therefore for EF55 I set the voltage to 350V and power to 16W. The amplifier that I made has been playing for 3 years and the person who bought it does not report any problems
Piotr
Tube EF55 has distances between individual electrodes are 50% larger than EL84, the thickness of the wire is 2X greater than EL84 the same size of anode or cathode. The voltage limit for EL84 is 300V, power lilit 14W, therefore for EF55 I set the voltage to 350V and power to 16W. The amplifier that I made has been playing for 3 years and the person who bought it does not report any problems
Piotr
Attachments
Last edited:
Fine,
THX for the pictures. What is Rp of EF55 in triode?
Today I bought 8 pcs of EF55, I will try them in PP.
THX for the pictures. What is Rp of EF55 in triode?
Today I bought 8 pcs of EF55, I will try them in PP.
