Another recomend me an PT

[Realeigo]

Helllo

Im building a 3 ch preamp, with three marshall voiced channels.
I want the same voltages as in a normal marshall amp.
So can anyone recommend me a PT?

I thought This one Wich would give me 350vdc after rectification (right?)
And 350 vdc should do the trick

[mooreamps]

You want to build a three channel pre-amp. We need to know the number of pre-amp tubes in the pre-amp.

-g

[Realeigo]

You want to build a three channel pre-amp. We need to know the number of pre-amp tubes in the pre-amp.

-g

8? 2 for chanel one, 2 for channel 2, 3 for channel 3 and 1 for the buffered output.

[Bruce / Mission Amps]

8? 2 for chanel one, 2 for channel 2, 3 for channel 3 and 1 for the buffered output.

There isn't much wiring diagram data there so I'm not very sure of the PT.
But, at 120ma, I would say that PT will be "current" over kill, even for 8 preamp tubes.
Also, 250vac@120ma secondary with what rectifier? I'm thinking a SS FWB.
Since it will be so lightly loaded I'd guess at seeing something like 360-380vdc.
Why? Because... the 250vac rating (if done correctly) means the secondary will hold 250vac while there is 120ma of current flowing.
My guess added the fudge factor of the PT being very lightly loaded and the actually Hi-V secondary making something like 265vac and the rectifier, no matter what you choose, will also be lightly loaded.
Never the less... those are still voltages that you can work with easily.

[mooreamps]

If you're just building a pre-amp, the heater load for 8 tubes calculates to 2.4 amperes. So no worries there. I also like the idea of using a toroidal transformer. I like it so much, I may actually look at this one myself, since I also tend to run my power tube filaments from a small separate 12 vct power transformer.

-g

[Realeigo]

And now onto the power supply, can i take the power supply from a marshall jmp and tweak around the resistors a bit to get the desired voltage?

[Bruce / Mission Amps]

And now onto the power supply, can i take the power supply from a marshall jmp and tweak around the resistors a bit to get the desired voltage?

Yes but because of the light loading you'll need some pretty large resistive values to get the voltage down.
I mean, 2ma or 3ma load from 1 dual triode will need a 25K to 15K resistor to drop 50v.
I think only your first dropping resistor will need to be a 2 watter and you could use 1 watters after that.

[Realeigo]

Included the choke? And the complete chain for the power tubes?

[Bruce / Mission Amps]

Included the choke? And the complete chain for the power tubes?

I never read anywhere you were using this PT for a complete amp with power tubes... it is my impression that this was only a preamp using an amazing amount of preamp tubes.
Eight I believe you said.

[Realeigo]

No power tubes, but i asked if i also had to clone te power rail part of the powr amp stage of a marshall.

[imaradiostar]

why not just use one of the low current and inexpensive allied brand PT's?

jamie