John Curl's Blowtorch preamplifier part II

[Steve Eddy]

Originally Posted by Wavebourn

It is more than different playing fields: it is different realities. I can't understand why in my reality I would need transformer rated for 5 times higher power than peak consumption of the whole amplifier.

For the very same reason one "needs" one of these to do their grocery shopping.



Edit:

In other words, it's a "guy thing."



se

[Wavebourn]

Speaking of grocery shopping, it is not the peak consumption: the same car can be used to go on camping in difficult road conditions. The analogy with John's transformer would rather be, an exhaust pipe that occupies the whole size of the SUV, and one seat for a driver only. The theory behind this would be, customers complained that Japanese cars had too small exhaust pipes before.

[jacco vermeulen]

Ooh, you mean a Formula One car.

[Wavebourn]

Originally Posted by jacco vermeulen

Ooh, you mean a Formula One car.

No, Formula One cars are well optimized for Formula One duty.

[scott wurcer]

Originally Posted by Wavebourn

No, Formula One cars are well optimized for Formula One duty.

At $1,300,000 MSRP they fit the audiophile model. When I went to buy my Saab the dealer had a demo of a McClaren F1 in for Jay Leno and he put a standard dealer sticker on it, US style MPG info and all.

[john curl]

Now, we have opened the controversy as to how much rated power a power transformer in an amp 'needs'.
Now I tend to relate to SOLID STATE power amps, because that is all I have ever designed for the last 45 years. I own several tube amps, but they were not designed by me.
However, now that I have your attention:
What IS the real power need of a power amp, and how much power should it be designed to put out: Continuously, on peak voltage transients, on peak current transients?
For example: IF you are making a tube amp, you can adjust the max 'power' by adjusting the output windings. It will be about the same with every assigned output transformer winding, 4,8, 16 ohms for example. AND to get more current, you have to TRADE for voltage output capability in a way that you always get essentially the same power out, SO assigning a power transformer for this application is relatively straight forward. This is apparently what Wavebourn is referring to.
However, for the design of a competent solid state power amp, the situation is somewhat different.
However, most solid state amps do NOT have an output transformer.
My amps are MUCH more powerful than the amps that Wavebourn is referring to, like 10 times more powerful into a 4 ohm load, for example, so we need a bigger power transformer. In this case, maybe 5 times the rated power per channel, and that is what we have, in our best designs. We also make much cheaper designs, and the output power and the power transformer gets smaller as well. Optimum? Maybe not.

[scott wurcer]

Originally Posted by Steve Eddy

Edit:

In other words, it's a "guy thing."

se

Steve are those the usual suspects with a power cord that "removes the last veil"?

[Wavebourn]

Originally Posted by scott wurcer

Steve are those the usual suspects with a power cord that "removes the last veil"?

I guess it is a power cord that increases power of a power grid.

[Wavebourn]

Originally Posted by scott wurcer

At $1,300,000 MSRP they fit the audiophile model. When I went to buy my Saab the dealer had a demo of a McClaren F1 in for Jay Leno and he put a standard dealer sticker on it, US style MPG info and all.

Did that sticker include MTBF numbers, or mileage between services?
It could be impressive to know how your SAAB outperforms such expensive machine.

[RNMarsh]

regarding power- a slightly different tangent to pwr xfmr rating -- is how much power do some people actually need. In my case, the size/volume of the room, effiiciency of the speaker(s) and the SPL capability of a real (acoustic) event, etal means I need at least 250W per channel for stereo. Then I have to find a speaker that will not be stressed to its max with that much power and then have all the other desieable speaker qualitities (power response, freq response, thd, IM, compression etc.) Less effecient speakers or larger room then means the $$ of the system really goes up... along with that pwr transformer size... thus digital amps start to have real meaning for some.

My moto is- if you cant afford to buy it, make it/design it yourself (DIYAudio) - so i made super analog mono power amps (900W into 4 Ohms at .01thd 20-20khz). The transformer is: You dont want to know. It was a labor of love.