Princeton transformer question

[weege]

Hello Gentlemen. I've been lurking on this forum for a while and must say that you guys are some fantastic builders and I admire the knowledge base here.

I have a question about a 275-0-275  90ma transformer being suitable for a Princeton style build. I know that voltage is low, but with the company's (Hammond) conservative ratings and a solid state recto, will it work? I'm mostly puzzled by the current rating:  the original spec was 81ma which seems a bit low.

Thank you for any explainations and Happy New Year.

[Raybob]

I believe 90mA wouldnot be enough and the transformer could overheat.  That's my guess-timation.

Raybob

[GibGa]

90mA is plenty for a Princeton IMO-esp in fixed bias where 2x6v6's will be drawing something around 23-26mA's ea @ the spec'd 400+/- Va -as I recall when I trialed one a year or so. 

I am fairly new at this also, but for the past 2 years now have tried many many versions of P/P el84 and *v6 types in cathode and fixed bias on my ugly homemade learning rig.  I have only a vintage Chicago potted PT that is 320/0/320@70mA.  Even in cathode bias with 300v on the plates and heavy 35-38mA on ea tube; it is at most a tiny bit warm then.  Keep in mind that voltage and current rating spec is the HT secondary only, the filaments etc are their own sections with their own ratings.

The Hammond's are great quality and known to be conservative engineering as you say. IMO many folks way over build stuff in our current era, but if the modern sound is what one wants then a stiff supply is necc.  Fenders Diode rectified Super Champ(simple Princeton) is similar to what you describe and likely has a smallish PT and is I believe bridge rect.

[phsyconoodler]

275 x 1.414=388v. Will work fine. The original Princeton Reverb PT is rated at 81ma.Hammonds guitar line is the same.Your 90ma unit will work just peachy.

[weege]

Thanks guys.