fetboy with altec input

hello,
i am getting ready to build a fetboy with fabios pcb. he used an oep input transfo but i already have a 15095a altec that i think scott recommended in the original hamptone design (on his site, not in the article). so, are there any recommendations on pinout or RL for that design? anyone using this? I also have a 15356 line xformer to use as the output iron. do i need to modify the design to use this?

thanks

ill post the results. im gonna have this and a baby animal in a 1 u rack, i can't wait to hear them.

oh yeah i have a 48v power supply that runs the baby animal and phantom so would it be ok to use a voltage divider using 2 120R resistors to cut the 48v down to 24? carbon resistors ok? if the jlm power is clean should i regulate after the divider?

thanks thanks thanks :guinness: :guinness: :guinness:

[quote author="buschfsu"]hello,
oh yeah i have a 48v power supply that runs the baby animal and phantom so would it be ok to use a voltage divider using 2 120R resistors to cut the 48v down to 24? [/quote]

That's not a good idea. You'll be dissipating 10W of heat from the two resistors alone...
Voltage dividers are hardly stiff voltage sources. So you'll load it down far to much.

You could try regulating the 48V directly to 24V but depending on how much current you need the regulators are probably going to get quite hot.

What kind of psu are you using? Isn't there a better way to get 24V from it?

i thought heat dissipation would be an issue.

im using jlm audio 48v wall wart to run a baby animal, phantom for it, and id like to run the fetboy and phantom for it as well. the fetboy will use probably 160ma of current and 24 volts.

how else to folks divide voltage when there are high levels of power to dissapate?


i don't want to put multiple wall warts into this chassis.

any comments on the iron suggested?

You can wire the 15095A in reverse. It's an output transformer, but can be used reversed as 150:15k. There is a diagram on this page about using transformers for MC set-up.

Just run a search, it's been done. I think it works pretty well, although the DCR of the secondary (used as a 150 primary) is kinda high, and I think the inductance is kinda low. It might sound great with a high output condenser, but loads ribbon or dynamic mics too much.

great thanks,

now all i need is the 48volt to 24volt solution. everything i read online (theory wise) talks about voltage dividers (using resistors). is there any other way? is there a regulator with a high power dissapation rating that would work?

thanks

I think that somebody mentioned in Fet Boy thread that he had used
48V for power suply of that thingie (that is 48 used instead of 24 for
amp stages as well as phantom). Find him and PM him for details.
That would be elegant and smart solution.

cheerz
urosh

I ran my JFP mic pre on the standard 24V, using a 25VAC tranny, diode bridge, and a 317 reg. I was going to add a second little regulator board in my power supply box to voltage double and provide phantom. Here is mine, and all the related threads are linked to below my pics:

http://www.groupdiy.com/index.php?topic=17030