Hiwatt dr201 PT

[tepsamps]

Hi,
i was looking for powerfull PT, and i found this one https://www.tube-town.net/info/daten...t-dr201-pw.pdf

I'm surprised to see the ratings of the high voltage windings, 1,3 A for a 200w amp, which is making 660 VA.

Is'nt it too big? I would have said 700/800mA, not 1,3A.

And the 400w version is (only) rated 1,5 A for the same voltages, why it's not 2,6A ? It's 760 kva for a 400w.

There is no real ratio ?

What do you think?

[catalin gramada]

Hi, I think they sell the same transformers as in link below. There are direct replacements. The specs are same,The price is same. Seems are made in Italy and no Chinese one. But maybe I.m wrong and it is their product...who knows... Usually get very good stuff from TT. Lemberg. Exceptional packing and very fast shipping. Go ahead !

Just for reference:
http://www.inmadout.com/T-power.asp
http://www.inmadout.com/T-set.asp

[Helmholtz]

In cannot completely explain the current ratios in the specs. But I assume that the PTs are faithful reproductions of the originals.

Just so much: Secondary RMS current times secondary RMS voltage is not real power but apparent power, which is higher than real power. The ratio between real power and apparent power is called power factor PF (<1). The PF increases (gets closer to 1) with higher DC current and same filter capacitance. So this might partly explain why the current rating doesn't double.

[tepsamps]

They are cheap, about 15 € per kilo of copper, good price :-)

[catalin gramada]

Man, I tried to take a look on You site to see what you,re doing. Is almost impossible, is full with crap promos adds. Make it little clear...

[tepsamps]

Man, I tried to take a look on You site to see what you,re doing. Is almost impossible, is full with crap promos adds. Make it little clear...

Oh yeah ! Don't you know addblock ?

[Gingertube]

These Transformers 2 x High Voltage Windings are both intended for voltage doubler power supplies, therefore the current ratings are X2 what you would otherwise expect.
Cheers,
Ian

[tepsamps]

These Transformers 2 x High Voltage Windings are both intended for voltage doubler power supplies, therefore the current ratings are X2 what you would otherwise expect.
Cheers,
Ian

Voltage doubler ? No! It's for dual rail power supply... https://hiwatt.org/Schematics/DR_200wPS.pdf

[catalin gramada]

double post , sorry

[catalin gramada]

It,s a "splitted" PT secondary, as well can run the amp in class B operation with max voltage the tubes can handle( think 800V to EL34) but keeping screens to a safe 400V. See old sixties Dynacords (Pinternagel designs) did it , get 100w from two EL34 at 800V. Dynacord used those powerstage circuit to death, even in semiconductors era. It seems it was very reliable.And we talk about Straubing factory not a garage production.You can stack two transformers as well, but is more convenient so.
...dual rail, yes

[mhuss]

Also, both the screen and plate current are flowing in the "bottom" half, so add another 10-20% for that. Plus, you don't really want to run the PT at 100% - think of the doom metal people running these things with everything on "10."