Tube Power Toroids [Q]

[nickt]

Last week I queried aussie trannie supplier, Harbuch Electronics, about winding a tube suitable power toroid. The response came back as $103 each or $74 for more than 10 (aussie dollars that is). This is cheaper than importing from Amplino (the only tube toroid supplier I'm aware of) but more pricy than cascading say two 240V:12V toroids.

So what am I on about?

Well it occured to me that a standard tube power supply with a standard trannie might be a good thing (perhaps we already have one in the G9?) but the specs for such a beast are unknown (to me at least).

So what specs should a standard trannie have? Here's my first guess:

- drive filaments for upto eight (?) dual triodes
- supply 200V - 300V (after regulation) for the above
- supply 48V (after regulation) for phantom power
- relay volts taken from unregulated filament winding

Looking at the wishlist I can see a bunch of ways to do it but I'm guessing the cost would be higher than justified for say dual V72's, REDD's etc.

So finally my questions:

- has this been done already? (can't see it via search if it has :shock
- is this a good or bad idea? :wink:
- what other way is there to tackle the issue?

Any thoughts?

Thanks

 

[rotation]

Hi,
not long ago i've been through this "story". First you need to decide which preamp you want to build and then get correct transformer.
I took G9's psu as an example, calculated current draw for B+ and heaters and bought transformers. They don't have to be nothing special (you were talking about tube transformers, they don't exist), just buy something with right ratings.
Gyraf chose two 230:12Vs because they are easy to get everywere and much cheaper then single custom transformer with different secondary windings.
You could also use Hammond trafos winded specially for tube gear, check them.

Good luck!

Miha

 

[nickt]

Thanks Miha - part of the reason I'm following in your path is I'm going to build a bunch of preamps and compare them, Aikido, G9, V72, R47... at least that's the plan :roll:

A standard supply that covers the ones I've mentioned is (I think) possible - electronically it's probably Gyraf's G9 one (although I really like analag's D-AOC layout of the circuit).

I was shocked when I did the sums for the PM660 (nearly 6A @6.3V :shock: ). So the one size fits all idea was pretty bad (unless maybe it's a switcher in a separate brick :twisted: )

You're right about two 12V's vs a single custom jobbie - but two trannies offend my "sense of neatness". :green:

cheers
Nick