Determine output power

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Re: Determine output power

Post by JMPGuitars »

TriodeLuvr wrote:
Tue 05/04/21 1:48 pm
The schematic for the 18 Watt Tremolo TMB indicates the EL84s are biased to about 12V. That means a 24V pk-pk signal at each grid will drive it to full output. A 6J6 would hardly know it's working! :)

With the bias voltages quoted in those docs, the tubes are biased at 85%. Obviously you would want to bias alternative tubes appropriately.
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Re: Determine output power

Post by katopan »

zaphod_phil wrote:
Tue 05/04/21 9:31 am
In my opinion, measuring the clean power output of a rock guitar amp is a waste of effort. The main reason we buy or build these amps is to hear them overdrive into their sweet-spot tones. Their "clean" tones still aren't pure sine wave, but have some distortion. As I've said in other contexts, this ain't Hi-Fi! :P
I somewhat agree Phil. But it's handy to know the ballpark to ensure an amp isn't going to blow up a pair of 60's original alnico speakers I have in my 1x12. I also like having a benchmark reference to compare amps against each other, fully accepting that the actual overdriven dynamic output power is not going to match my theoretical clean value.
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Re: Determine output power

Post by Doxie man »

Raezzordaze wrote:
Wed 04/28/21 11:13 pm
I love people saying how Doug was wrong, yet no one posts anything about the correct method to measure output either. :roll: I mean, ok, maybe he wasn't engineer level correct but, from other videos I've seen, he's pretty damn close. Granted, I'm no engineer myself, so if someone wants to post the actual power output measurement methods feel free. But I feel Doug's done a lot to educate and inform people about tube amps on a basic level so why all the hate? I mean, if he's legitimately telling people to do dangerous things why not highlight that either on his videos as a comment or here in regards to that video?
…..because there’s always somebody wanting to look smarter on the internet 😂. All joking aside, Uncle Doug does a pretty good job at explaining a lot of things in layman’s terms for the beginner. Is he 100% right on everything he says and does ? ….nope BUT neither is anybody else 👌….including ME. we are all human and we all make mistakes.
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