Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: johnheath on June 26, 2011, 02:06:59 pm

Title: Power Transformer Q
Post by: johnheath on June 26, 2011, 02:06:59 pm

Hello

I am about to design an amp and I just have a few questions concerning the capacity of the power transformer.

I will build a "Tweed Super" but beefed up with a OT just like in a Super Reverb Blackface (125A9A) or (125A13A).

Now: The traditional TAD/MOJO 125P5DX or the Hammond 290DEX both matching 230mA but since I am only using two preamp tubes two 6L6 and a GZ34 rect. tube my question is if I can get a "smaller" PT that let's say deliver 173mA like the Hammond 376X... OR?

Am I looking at completely wrong facts here?

One of the benefits with the Hammond "Classic" 300-series is that they are top-mounted and requires no big holes to be mounted on the chassis... and this would ease my thoughts on building a really small but still powerful amp with real PtP.

Regards

/John

Title: Re: Power Transformer Q
Post by: eleventeen on June 26, 2011, 04:42:29 pm

The preamp tubes use very little current...2-3 ma, usually. So they make very little difference in the overall scheme of things. Sounds to me like your proposed PT can easily handle the job.

Title: Re: Power Transformer Q
Post by: phsyconoodler on June 30, 2011, 06:37:51 pm

Are you in Europe? If not,the 272HX will do the job.The 372 version has 230v taps and a bias tap that the 2&2 does not have.