Dyna ST70 PWR Tranny 6.3V Crnt Spec?

[kegger]

Anybody seen/know what the 6.3v windings on the Dyna 70's current ratings are by chance. (original)

I mean we obviously have 3a for both EL34, then .45a for a 7199 plus the pre socket out front on each side.

So what 4a, 4.5a?

 

[DigitalJunkie]

The manual says that it can supply up to 1A at 6.3V to each preamp socket. So that's ~4.45A per channel.

 

[kegger]

Thank you kind Sir!

As I'm looking to use 4.2a per side on the 6.3v windings and not use the 5v winding at all.

I was hoping my plan has a chance to work and sounds as if it just may.

 

[DigitalJunkie]

Yea,That should work nicely.

 

[danFrank]

Original Dynaco said that it could provide the extra 1 amp per winding but this was an exaggeration. Current through the outputs was also exaggerated in their specs, realistic numbers are 40ma per EL34.
A realistic value for each 6.3volt winding is 3-3.5 amps tops.
Daniel

Edit: I just saw that you won't be using the 5 volt winding, so this will give you some extra elsewhere in the transformer. Try your circuit out and see how hot the transformer gets. If it's too hot to put your hand on it, I would ease off a little. You can always put a small filament transformer under the chasis.

 

[kegger]

Humm, in stock form with nothing plugged into the front your running 3.45ma all the time.

I know the power tranny's in 70's run hot but I've still yet to see a dead one. (yet that is)

Was hoping that not running anything off the 5v winding may help some as well. (yah you saw it)

We'll see how it goes.

Thanks,
keg

 

[MQracing]

Hi Kegger:

From the orig factory blueprints each of the two separate 6.3vct windings are rated at 4 Arms.



MSL