Hi
I will soon start building a stereo 2A3 amp.
I have looked around the web and only found 1 choice for the power transformer. The Hammond 302AX. All the other Hammond don’t have 2.5V windings.
The other option was Edcor XPWR067, would of been perfect but it was withdrew from their list. I contacted them and they won’t reinstate that model...😡
So any recommendations besides the 302AX ?
My other option is to buy a PT which doesn’t have the two 2.5V windings and buy two separate Triad F1-X.
TIA
Eric
I will soon start building a stereo 2A3 amp.
I have looked around the web and only found 1 choice for the power transformer. The Hammond 302AX. All the other Hammond don’t have 2.5V windings.
The other option was Edcor XPWR067, would of been perfect but it was withdrew from their list. I contacted them and they won’t reinstate that model...😡
So any recommendations besides the 302AX ?
My other option is to buy a PT which doesn’t have the two 2.5V windings and buy two separate Triad F1-X.
TIA
Eric
With both you and Hammond being Canadian, that 302AX power "iron" strikes me as being near perfect.
An alternate possibility is acquiring 6A5G O/P tubes and heating with 6.3 VAC. That tube contains a cathode sleeve wired to the center of the heater, which automatically controls hum, but otherwise works like the 2A3/6A3/6B4G DHTs.
An alternate possibility is acquiring 6A5G O/P tubes and heating with 6.3 VAC. That tube contains a cathode sleeve wired to the center of the heater, which automatically controls hum, but otherwise works like the 2A3/6A3/6B4G DHTs.
Thanks Eli but I’ve always had bad experience w Hammond, I find them all noisy (mechanically), all the models I’ve tried.
Thanks for the tips about 6A5G but I already have the 2A3.
BR
Eric
Thanks for the tips about 6A5G but I already have the 2A3.
BR
Eric
Does it have to be a traditional style transformer, or will a toroid work? It's pretty easy to add windings of nearly any desired voltage to them, and for only 2.5 volts each winding it would be quite fast to figure how many turns each winding will need to be. Then you can grab something from triad, antek, etc. Even with the exchange rate and shipping it might be worth the fuss.
I've added windings to a bunch of surplus toroids and I found adding ten turns to start and doing the math always gets you very close, then you can add a few extra turns to account for sag under load.
I've added windings to a bunch of surplus toroids and I found adding ten turns to start and doing the math always gets you very close, then you can add a few extra turns to account for sag under load.
Hammond's open-frame filament transformers (166 or 266 series) might be the way to go.
There's nothing to buzz here - no screws, no bell caps, nothing.
Or the Triads indeed.
There's nothing to buzz here - no screws, no bell caps, nothing.
Or the Triads indeed.
I power the 2A3 tubes filaments with individual transformers because it allows me to use two power on switches: one for the filaments and one for the plate supply. I turn on the 2A3 filaments, wait about 30s. and then turn on the plate supply.