The arguments for high power vs low power Single-Ended tube audio amplifiers have been made for decades and there are many. It seems both have their strengths and compromises. But audiophiles often ask if there is a way to get the subtle details and life-like nuisances of a class “A” SE tube amp in a higher power amp design able to drive any speaker to louder volumes, especially for larger rooms. Typically the answer was “no”, or at least just a “maybe”. Sure SE amps can be made to provide double the power of the famed 300B tube‘s 8W output, perhaps triple that power. But we’re talking about a REAL power increase. Something dramatic. Well folks, now the answer is, “YES!”
NAT Audio recently released their Magma New SE monoblock tube amplifiers. These amps are rated for output up to 170 Watts @ 4 & 8 ohms! It uses only two tubes per channel so the signal path is not messed with like it is in typical high-power amp circuits using several times as many tubes. The input/driver tube is the common 6N1p-EB tube. The output power tube is certainly not common – a GM100 power triode, intended for use in transmitters.
Oh yeah, each monoblock weighs in at ~133lb so you’ll want to invite your audiophile buds over to help with unpacking and setup. 🙂

We found this little video on Youtube that will give you a close look inside the GM100 triode tube:
I swear the glass bottle and construction sort of cross between a vacuum tube and HID 400 Watt bulb. HID lights are found in commercial or some industrial application buildings with high ceilings … unlike our vacuum tubes ..HID essentially arc from a high voltage discharge to ignite the vapour capsule. Should vacuum tubes arc ….its game over!!!!
Hi !
What kind or level of voltage is used in such a power plant ?
Thanks !
Honestly I don’t know but expect well over 1000V.
Le tube a une alimentation de 2000v, pour 1,5mA de courant
le chauffage est de 17V pour 18A
sacré transfo pour alimenter cela !!!
I like the sound of the 833-A run at zero grid bias and 1 KV fed by a parafeed innerstage step-down transformer drive 245. The Hammond 1642SE is a good match for the 833-A to drive the speakers.
Le tube a une alimentation de 2000v, pour 1,5mA de courant
le chauffage est de 17V pour 18A
sacré transfo pour alimenter cela !!!
The filament consume 300 watts,
The bulb can consume up to 1KW (it can work up to 5KV, and maybe need at least 2.5KV with more than 300mA idle current)
Het ziet er bijzonder mooi uit maar ik denk ook dat het enorme stroomslurpers zijn!
Gezien de energieprijzen lijkt mij dat nou niet zo,n verstandige keuze.