D'lator power transformer (230V Mains)

[rob@tele]

While collecting all components for my Dlator II build, I've had problems finding a proper power transformer for 230V mains (I'm living in Holland). Now I am in the process of getting a toroidal transformer designed that fits inside the 1HE 19" housing. As the cost will decrease when I order a larger series, I was wondering if there are other members (europeans) on the forum that would like to have one too. Please send me a PM if you are interested.

Regards,

Rob

[ayan]

While collecting all components for my Dlator II build, I've had problems finding a proper power transformer for 230V mains (I'm living in Holland). Now I am in the process of getting a torroidal transformer designed that fits inside the 1HE 19" housing. As the cost will decrease when I order a larger series, I was wondering if there are other members (europeans) on the forum that would like to have one too. Please send me a PM if you are interested.

Regards,

Rob

Rob,

You can use a 1:1 transformer and put a bridge on it. That will give you about 325 VDC, which is what you want to have. For the heaters, 6.3 ideal or 12.6 VAC if you want to run the heaters in series. However, the latter arrangement can have a little more heater noise present in the circuit.

Gil

[rob@tele]

Gil,

Would 325V be sufficient? The schematic shows 368V. What will be the allowed range for proper operation?

I'm still waiting on a quotation for the transformer,

Regards,

Rob

[ayan]

Gil,

Would 325V be sufficient? The schematic shows 368V. What will be the allowed range for proper operation?

I'm still waiting on a quotation for the transformer,

Regards,

Rob

Not sure how the schematic can show 368... The Dumbleator uses a 1:1 transformer in the US with a voltage doubler, so you get basically 2 * 120 * 1.41 (- diode losses), which is approximately 338 VDC.

Gil

[dimitris]

Gil do you think that the following transformer is suitable for a 230v D'lator?
Musikding transformer
"Small power transformer for tube projects. Primary 230V, secondary 230V 0,12A, 20V 0,12A and 6.3V 4A."

Thanks
Dimitris

[ayan]

Gil do you think that the following transformer is suitable for a 230v D'lator?
Musikding transformer
"Small power transformer for tube projects. Primary 230V, secondary 230V 0,12A, 20V 0,12A and 6.3V 4A."

Thanks
Dimitris

Dimitris, that transformer seems to be an overkill for the project, I think. You have 0.12A out of the main secondary, while a 12AX7 stage draws maybe 1mA or so. That beast is good for 27W and also, on the filament tap, you get 4A while each 12AX7 draws 300mA. It looks like that tranny could be used for a small amp with a few preamp tubes and a couple of 6V6s, like a Princeton type. It will definitely work, but I suspect the unit cannot be physically small... is it? If it fits inside a 1U rack unit, cool, otherwise you can certainly do with something much less robust for a little Dumbleator.

Gil

[dimitris]

Thanks Gil.I guess You are right that it will be too big for a 1U chassis.I'll try to find something smaller.

[rob@tele]

Gil do you think that the following transformer is suitable for a 230v D'lator?
Musikding transformer
"Small power transformer for tube projects. Primary 230V, secondary 230V 0,12A, 20V 0,12A and 6.3V 4A."

Thanks
Dimitris

Dimitris, thanks for the tip. I have found that they do have a suitable toroidal transformer
It requires full rectification of the 270V (so no voltage doubler) and the 14V should be used to create regulated 12V in order to suplly the filaments wired in series.

Regards,

Rob

[nickm57]

Has anyone tried one of these, voltages look a little high.


http://cgi.ebay.com/Dynaco-PAS-Pwr-Tran ... m153.l1262

Nick

[Funkalicousgroove]

The actual tranny in dumbleators is a triad r-2c which has a 115v primary, and a 135-0 secondary, 135 on a voltage doubler with 120VAC into a 115v primary should give you about 368v under load- However, the intended voltage should be more like 340ish.

[dimitris]

Just found this Uraltone transformer.
The specs look right and it's not that big.Has anyone experience with that shop?

[mat]

Just found this Uraltone transformer.
The specs look right and it's not that big.Has anyone experience with that shop?

I have bought almost all from there I have needed for the 6 amps + 40 pedals I've built. Mikko is super cool guy. Highly recommended !

[dimitris]

Thanks Mat.