Does this Transformer Exist

[kurtlives]

Hi just wondering if there is a transformer like this out there....

I want one with the following taps...

120V
0V
5V
0V
12V
0V

Its for the power supply of a tube pedal. I want to use a tube rectifier instead of a solid state one.

Thanks...

[dxm1]

So you're looking for a transformer with a 120VAC primary, and a beefy 5VAC and 12VAC secondary? Probably not. Most transformers designed for tube rectifier applications would have a very high voltage secondary, 6.3VAC for heaters, and maybe a 50-70V tap for bias in addition to the 5VAC.

Your best bet may be to go with two seperate trannies - 120VAc primary, and a 5VAC/2A (5Y3) to 5VAC/4A (5AU4) secondary, and a 120VAC/12VAC tranny for your heaters and B+.

You could also look into using a 12X4 rectifier, which can put out about 240mA of 360V rms using less than an amp of 12VAC for the heater. That way you'd need only a big, honkin' 12VAC secondary. Check tube specs and data sheets...

[kurtlives]

Ya I figured I would not find anything as low as 12V on the secondary....Luckily I have a 120V/12V in my possesion now....

So I guess all I need is a 120V/5V right.....

Also is a 5Y3 tube the standard when it comes to rectos...? Like what would different tubes do?

[dxm1]

So I guess all I need is a 120V/5V right.....

You could also look into using a 12X4 rectifier...

Also is a 5Y3 tube the standard when it comes to rectos...? Like what would different tubes do?

Check tube specs and data sheets...

[Jered]

  If your trying to fit this in a pedal, why not go with standard 1N4007's for rectification? Just add a standby switch,...and use it and you'll be fine. Most 5U4 rect. tubes are bigger than a standard stompbox. That would be a sight!
  Jered

[soulsonic]

This seems like a bad idea to me.

[Paul Perry (Frostwave)]

I don't think it is likely that having a tube rectifier will in any way improve the performance.
In a pedal, there isn't going to be enough current drain at peaks to give a voltage sag at peaks - the only reason you might want a tube rectifier.

[kurtlives]

Ya I was just seeing if it was as easy as I thought. Aparently not... No tube recto on my tube reverb pedal then....

[Zben3129]

Ok heres my suggestion...

Even though he tube recto won't be any different than standard rectification in a tube pedal...

Get a 120/6.3 or6 transformer that puts out a decent amount of current, enough for all your filaments. Or you could use a 240/12 (euro) transformer,
Then use a 6ax5 rectifier tube that uses 6.3v on the filiments.
Take your filiments from there

Then, put it into the secondary of a 120/6 for B+. I've never tried this, but if you used again another euro xformer, 220/6, to get 220 B+

Zach

[brett]

Hi
the main reason why tube rectifiers are good is that when lots of amperage is drawn, the voltage "sags" because of high resistance in the valve.  Cool.  However, low current devices don't cause any sag and solid state and valve rectifiers sound exactly the same.

However, you can simulate the extra resistance in a valve rectifier easily enough.  Simply put a 100 ohm or 150 ohm resistor in the B+ line, in between the power supply and the tube pedal/tube pre-amp/tube overdrive, etc.
cheers

[drewl]

I recently ordered a power tranny for a Crate amp that had two 12AX7 preamp tubes with a solid state output section which had similiar outputs.
So that's where I'd look, at a hybrid amp trans.
usually about $50-$75....
or check out what Hammond has.