Valve amplifiers

I certainly hope so!

I always took THD as total harmonic distortion. I can't imagine why anyone would be interested particularly in the distortion caused by the third harmonic, unless you were creating a Hammond organ or such.

Don't forget the old display-the-peak-to-peak-instead-of-RMS trick. That usually multiplies the actual figure by 140% or so (I think).

But the thing about the distortion is a good point. I once saw an amp that was rated at "100W RMS", yet it started to distort at about 65-70W...

Andrew Howard

The other feature of some of those power amps of the ratings wars of the '70s was "instantaneous power". The power supply was underrated for the peak load, so as soon as the (smallish) supply caps sagged after a few msec, the output would clip. But they got lots-o-watts for the first couple of cycles of output! I wouldn't be surprised if guitar amp makers got caught up by this craze as well,

Best regards,

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

Did you not read my posts on this:-)

This isnt really "instantaneous power", its "average transient power" during those ms.

RMS power really means "average power over a cycle". "Instantaneous power", is the single instant VI product, that dont really mean much. "Instantaneous power", would be the power at *max VI*, not average of the cycle, and would normally be specified under *steady state* conditions *after* the supply had sagged!!!

I doubt that many manufactures specified max power by a burst sine test.

Yeah, this is all a bit confusing aint it. "Instantaneous power" isn't, and "average power" isn't necessarily long term average power, it might be only the average power during the first few ms.

Which is all that is required for clean guitar picks.

As I explained in another post, capacitor size/cost can make this effect automatic.

Kevin Aylward snipped-for-privacy@anasoft.co.uk

....

your ego

No offense taken, ego is fully intact... In fact, I feel the need to thank you for setting me straight. :-)

Say Kevin, it sounds as if you play guitar or some musical instrument(s) yourself, yes?

P.S. I wouldn't be any better at giving play tactics for American Football.

Yes. Some info on that is here

Music and electronics for music went hand in hand.

Kevin Aylward snipped-for-privacy@anasoft.co.uk