Differences between Carlsbro 40TC and 60TC

pintspiller

I am asking about the heads here. Surely if they both run EL34 valves they should have the same output. Is it all down to preamp?

ecc83

Oooo! We had a Carlsbro  combo (***k! 40+ years ago!) 4 inputs, EVERYTHING went through it.

No my clumsy friend, the power output of a pair of 34s depends upon the HT voltage and how the circuit is designed. From "our" stable there is a 2x EL34 that delivers almost bang on 20 watts, mainly due to it being mostly cathode biased. Top of the two valve range is the 60 Stage and that can actually deliver 80W.

According to "the Book" a pair of EL34s running at a "takes no prisoners" 800V can give 100W tho' I doubt anyone would try that with modern (aka mostly crap) valves!

Dave.

ICBM

As Dave said it’s mostly down to the power supply - voltage and current delivery capability. Power stage design also comes into it. It’s nothing to do with the preamp unless the maximum output is limited by unnecessarily clipping somewhere, which would usually be considered poor design.

The Fender Hotrod Deluxe and Deville are similar - both 2x6L6, one 40W and the other 60W. Higher power supply voltage and bigger transformers in the Deville gives more output power - there’s no other difference, the preamps are identical and they’re even built on exactly the same PCB. I wouldn’t be surprised if the Carlsbros are too.