Options for 5F1 transformer

[Marn99]

So now that classictone is gone, I have been trying to find an alternative for a power transformer for my 5F1 build. I already have the audio transformer, that one IS a classictone, but their power transformers are already sold out at Stewart Macdonald. The main one I have been looking at is a Hammond, but I have also looked at Heyboer (sorta, their website is way outdated). I have also been thinking of looking at the manufacturer that Leo used in the 50s, and seeing if Triad has a power transformer that fits. What experiences have you all had in the past with these brands, and which do you reccomend?

 

[James Knox]

I love this one...

100ma, plenty of current

red and white 275V taps gets you perfect 5F1 B+

green and yellow Heater Center Tap avoids “Artificial CT”

 

[ThermionicScott]

I like the specs on the Heyboer: (link removed)

In fact, I would choose it any day over the 650VAC-only 40-18019 and 40-18122 from ClassicTone.

 

[Jimy]

Magnetic Components (the maker of ClassicTone) announced that they would shutter the factory in early November. It would surprise me if all the supplies have dried up already. Tube Depot seems to have the tranny you want in stock:

https://tubedepot.com/products/classictone-power-transformer-40-18019

As to the long term picture, I would look at Heyboer for comparably priced / good quality alternative. You can buy them from Mojotone.

 

[Nickfl]

Some other options, both happen to be cheaper than Hammond.

Edcor: (link removed)

Weber: (link removed)

Edcor is made in the US and at least look and feel nicer than classic tone did IME, but be warned, they will take their sweet time getting to you.

Weber's transformers are made overseas, but the couple I have had seemed to be comparable in quality to classic tone.

 

[screefer]

both happen to be cheaper than Hammond.

The Hammond AX weighs 2 lbs. 15 oz.
The Edcor weighs 4.5 pounds.
The Weber doesn't list a weight

In your experience does that make a difference? Does a stouter Tranny reflect in performance?

 

[Jsnwhite619]

The Hammond is plenty for a Champ. The same one is offered for a Princeton Reverb.

Same with the OT, if you are building a stock or mostly stock Champ with a 6v6, save some weight and money and stick with a 5W-6W Champ style OT. I've built two 5f2a Princetons that were identical except one had the Classictone 5W OT and the other had ClassicTone's 15W upgrade. I A/B'd the two of them and could finally tell some minor difference in the tone (I think), but it was not worth the cost or extra weight (especially the weight) to warrant doing again. A 5W OT works great for a 5W amp...a 15W OT does not turn a stock 6v6 Champ into a 15W Champ. You'll get bigger difference with multiple primary options - 5k or 8k, etc. - than you'll notice with a heavier OT.

 

[Nickfl]

The Hammond AX weighs 2 lbs. 15 oz.
The Edcor weighs 4.5 pounds.
The Weber doesn't list a weight

In your experience does that make a difference? Does a stouter Tranny reflect in performance?

Theoretically, you would expect a heavier transformer to sag less and heat up less. The thing is with different manufacturers it may be as much an issue of different materials and construction though so I wouldn't assume too much. I wouldn't worry too much about it with a PT. It would probably matter more if we were talking about an OT, where it may indicate differences in output power and frequency response.

I have noticed that some Hammond transformers seem to be smaller and lighter than supposedly comparably speced transformers from other manufacturers, but they still seem to perform well...

 

[ThermionicScott]

The Hammond AX weighs 2 lbs. 15 oz.
The Edcor weighs 4.5 pounds.
The Weber doesn't list a weight

In your experience does that make a difference? Does a stouter Tranny reflect in performance?

Some of these transformers are heavy because they're over-spec'd for the job. A 5F1 (or 5F2A, or BF/SF Champ, etc) needs about 40mA for plate current, 0.75A for the 12AX7 and 6V6 heaters, and 2A for the rectifier tube heater. Now look at the specs for the Edcor PT: 100mA, 2.25A, and 3A respectively. To deliver all that extra current, you need more iron and thicker wiring to avoid overheating.

I could buy an argument that this is done to improve reliability, or to make it more flexible (like if you wanted to sub in a 6L6 and 5U4), but there's a good chance that if you just use it for Champ duty, the voltages will end up too high (not enough transformer sag). So, I like to use iron that fits the job description as closely as possible.