Tuning tube amp on low power?

[REDDOG45]

Is it safe to tune a tube type amplifier, like my D&A Phantom, and Maverick on low power? It seems to me that this would be better on the tubes rather than pounding them on high?

[Ohio_359]

No, tune for max forward power.

[REDDOG45]

I mean tuning for max forward power on low side of amp?

['Doc]

If you normally would run the thing on low power then tune it that way. If you normally run it on high power then tune it that way. If you change between the two, it's a good idea to retune anyway.
- 'Doc

[REDDOG45]

Doc, I was thinking about tuning on low, and using on high, but what you are saying makes good sense.

[drdx]

Something else on that, a common tuning method is to tune on high, not talking, and then rotate the LOAD to teh point it reduces the carrier 10%, so it has max fwd swing. You can do that, or if you have a peak reading meter you can peak it on high for deadkey in the non pep mode, then put steady audio into it, set the meter to peak, and move the load and you'll find a sweet spot where the peak is better, often buy turning the load more clockwise. I think doc is right in tuning it where you are going to use it but I'm not technical enough to know if that's the best route. I'd run it on high and adjust the drive to the amp for the desired result. That way, the amp has plenty of "ceiling" to do what it does to the signal and doesn't limit it by the low setting. Amps do vary, as do designs and tube characteristics, so posting the amp model may shed a lot of light on the situation.

-drdx

[REDDOG45]

What if I were to tune the amp for max dead key and not swing?

['Doc]

Think about that for a minute.
The idea behind tuning that amplifier is to optimize it's efficiency in operation. That doesn't mean trying to get the absolute highest output from it, but to make it work the best it can at whatever power level you will be feeding it. That means that if you tune the thing for a lower power input, it won't be optimized if fed with a higher power input, or visa-versa.
How much difference would there be, and would it necessarily be just 'not good', or terrible? That depends on the particular tube or transistor device(s) used in that amplifier, and how much those devices are being 'pushed' above their normal/rated abilities. Some devices can withstand more 'abuse' than others. So, tuning the things for the highest input power is a pretty good idea. Just make sure that isn't 'too much', you know?
- 'Doc

[Ohio_359]

The idea behind tuning that amplifier is to optimize it's efficiency in operation. That doesn't mean trying to get the absolute highest output from it, but to make it work the best it can at whatever power level you will be feeding it.

Good point. Tuning a tube amp is not the same as squeezing every last watt out of a radio, or overdriving the snot out of a transistor amp to make the meter swing. You are truely "tuning" a circuit, and with that comes more efficiency. Tune for max forward swing and just don't overdrive it.
"

[REDDOG45]

ALl this makes good sense. I have also been told not to whistle into a tube amp while tuning for max power. Is it a bad idea?

[Night Crawler]

If you want to tune it with a tone use a 1khz sine wave.
[Please login or register to view this link]