Amplifier for headphones. A lot of time I devoted to studying the question - which valves are best for sound from low-power. I found next 2 favorits: PX4 Marconi-Osram 1 generation with barium anode (1920s) Sonatron 71a (171-A). Any body hear this tubes? Are there any better ones? Thanks. Best wishes.
The first thing you must do is decide what parameters you require as that alone determines the amount of distortion produced by the choice of valve.
The size of valve, anode area/cathode material determines the amount of power that can be produced and other parameters.
So, there is no best sounding valve.
The size of valve, anode area/cathode material determines the amount of power that can be produced and other parameters.
So, there is no best sounding valve.
Agree.
On this moment definitely i thick only - output power 0.1-1 watts, and impendance 32-42 Ohm.
Other parameters - too width range of conditions.
Just best sound.
Thanks!
Great!
I don`t hear earlier about 1626 and VT-137.
The datasheets say 4.5 watts at 4% THD for a SE PX4- a bit better than 2A3. The Soviet 4P1L is very popular on this forum and there are a number of lengthy threads you can check.
Another good tube in that amp is the 12B4 tube using an adapter. It will yield a bit more power and is more open sounding. They glow nicer too!!🙂
PX4 first generation take much small power - 1 watt.
PX4 audio valve, power triode technical data
They sound too very better then next generations with much higher power.
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How about trode connected 4P1L? Can do a single per side or parallel them as needed. Triode connected 6P15P will also come very close.
Hard to beat a triode connected 6V6 too.
Or, if you don't have to be SE, a nice little 6SN7 push-pull?
Hard to beat a triode connected 6V6 too.
Or, if you don't have to be SE, a nice little 6SN7 push-pull?
Actually, yes it will. It can swing 40mA into the load which is only 50mW into 32R though. Still, 50mW is plenty for sensitive cans. My main set is actually 470R though so it'll push 750mW into them!
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Try 6P15P in triode mode. You will be surprised. Less problematic filament and bias than with 4P1L.
Not sure what the max is, but I'm running a set at 260V or so and they're fine. Screen connected to plate through 220R.
I have some datasheets for the -ER suffix type which states 330 V for both anode and screen.
Also, 65 mA cathode current max, which is useful since most of the other datasheets just give a pulse current max. Maybe needs a bit of derating since the -ER has a slightly (800 mA) more powerful heater.
Also, 65 mA cathode current max, which is useful since most of the other datasheets just give a pulse current max. Maybe needs a bit of derating since the -ER has a slightly (800 mA) more powerful heater.
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