Tube-Town Forum
Technik => Tech-Talk Sicherheit => Thema gestartet von: Leadman am 25.09.2021 19:50
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Hello,
We can see in the Tube Town website the following specs for the 5e3 style power transformer:
5E3 Powertransformer , laydown (tt-5e3-vpo)
Pri.: 0-230V-240V (50Hz)
Sec.1: 320-CT-320 V @ 85 mA DC
Sec.2: 6,3V C.T. @ 2,5A
Sec.3: 0-5V @ 2A
5E3 Powertransformer , vertical mount (tt-5e3-pw)
Pri.: 0-120V / 0-110V-120V @ 50Hz
Sec.1: 320-CT-320 V @ 85 mA DC
Sec.2: 6,3V C.T. @ 3,5A
Sec.3: 0-5V @ 3A
Looking at LX18 schematic using 5e3 vertical mount transformer the HT rectified put out over 420V on the 6v6s (jj) plates biased at 50mV.
I have a recent built amp with 2x6v6s (jj). Using the 5e3 laydown power transformer, I can get only 390V at plates biased at 43mv. If I try set the bias hotter the Voltage goes down.
Math says that a 320-0-320 HT power transformer would put under normal load about 320x1,32= 422V (that is confirmed in LX18 schematic), and the answer is:
Why I can get only 390V out of the laydown version if the HTs specs are the same?.
I wanted to build a BrownFace deluxe, but the final voltage is a bit low for my target.
P.D. Itīs true that sec2 and sec3 can put out more current in the vertical mount version, but it should not affect the HTs taps.
Best Regards.