Power transformer for MK-U47 PSU having 6.3V secondary?

[fazeka]

Hi all,

Where can I get a toroidal power transformer similar to a Triad VPT230-110 but also having a 6.3V tap?

In other words I need 115 on primary (I live in the U.S.), 230V on the secondary,  with another 6.3 secondary tap.

Cheers,
Chris

 

[Khron]

"Retail", i have serious doubts you'll find anything like that, so your best bets are either to go custom (which could get pricey), or just use two separate transformers.

The high-voltage one may well end up smaller than the heater one, since you only barely need single-digit mA figures for the plate current

 

[fazeka]

Hi Khron,

It was member stribor1 (in the MK U47 build thread) that used a 30VA toroidal from Tube Town (Germany) with the 6.3v secondary that got me thinking about that. I only want the 6.3v tap for a pilot light (#47 bulb). I thought about purchasing a small filament transformer but wasn't sure if this would introduce noise/hum into the power supply and thus the mic... thoughts/comments?

Or, what do you think of this?

http://www.tube-town.net/ttstore/Transformer/Power-Transformer/Toroidal/Toroidal-30VA-US-Version::6842.html

Cheers,
Chris

 

[Khron]

I think you could safely power something like 5 (or more) tube mics with those sort of ratings 30VA's a bit overkill imho, but sure, it oughtta work (more than) fine.

 

[fazeka]

Thank you.

Would a small filament transformer have a chance of introducing more noise into the power supply?

 

[fazeka]

Let me ask this and make sure what my intention is makes sense. What I was going to do was just use this kind of bulb:

http://www.mouser.com/Search/ProductDetail.aspx?R=8-3995virtualkey60600000virtualkey606-CM8-3995

and take 120v to the lamp holder, like this:

https://www.tubesandmore.com/products/P-L124-P

But thought that was too much voltage to something like that and thinking it would be safer to use 6.3v instead.

Thoughts?

 

[ln76d]

Thank you.

Would a small filament transformer have a chance of introducing more noise into the power supply?

If both will be EI core - yes you can have a problem in a small box, so you you will had to find proper placement orientation etc.
If one will be toroid - it shouldn't be a problem.

 

[fazeka]

If both will be EI core - yes you can have a problem in a small box, so you you will had to find proper placement orientation etc.
If one will be toroid - it shouldn't be a problem.

Hi, thanks for your reply.

I am running the Triad VPT230-110 toroid for the 230V.

So, I was thinking about a Hammond 166F6 for the 6.3V. Would that be considered an EI core?

Cheers,
Chris

 

[ln76d]

Yes, it's EI, but since the main transformer is toroid shouldn't be a problem - at least i didn't had any problem with that configuration

 

[fazeka]

Great. Thank you!  ;D