why not use auto formers?

[burro breath 10+ year member]

ok so my father is very very big into home audio. his macntosh amps are very high end and use auto formers. this causes the amp to never accually see the load in ohms and there for can be used at a dead short. so my question is why dont the amp manufacturers use autoformers and not worry about the ohm load they can handle. yes i do realise that my fathers amps are on a much higher class of amps but with all of the people trying to get the most power it just seems to me that you could use an amp that uses auto formers and match it with a quad 1 ohm speaker brigded down to .25 ohm and have it really hit hard. if anything i am asking is incorrect please feel free to correct me provided that you know what you are talking about, i am trying to learn.

thanks for the help,

burro.

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[dragnix 5,000+ posts]

is that like the robots in disguise?

 

[terra 5,000+ posts]

cheese whiz:fyi:

 

[burro breath 10+ year member]

cheese whiz:fyi:

my point exactly hopfully squeak will chime in to help me figure this one out.

 

[helotaxi 5,000+ posts]

Stinger and Veritas both used to market Accumatch impedance matching transformers. Once power became dirt cheap, the need for them became about zero. They were great when you were talking about having only 25-50 watts on a channel. The tranformer could be small and the small amount of power wouldn't saturate the core. More power means a larger transformer which means a higher inductance and all the ill effects on the signal that go along with that.

If power is cheap and multicoil drivers are available that can let you wire to pretty much any impedance that you want, and a transformer big enough to work with the power available would trash the sound, why would you want one at that point?

 

[Haunz 10+ year member]

Dude... your father's amplifiers are more then likely tube amps..... which amplify CURRENT and not voltage....

They need to use transformers to transform the amplified current into an appreciable amount of voltage to run a regular speaker.....

understand ?

 

[azbass 5,000+ posts]

thats McIntosh //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[burro breath 10+ year member]

Dude... your father's amplifiers are more then likely tube amps..... which amplify CURRENT and not voltage....
They need to use transformers to transform the amplified current into an appreciable amount of voltage to run a regular speaker.....

understand ?

no they are not i am 100% positive of this. and for the person saying they only used them for lower wattage applications that is fairly wrong as well my fathers amps are 250watts rms per channell for just the mids.

 

[helotaxi 5,000+ posts]

250W is still pretty low power. The Accumatch came in 100W and 300w models. Of course at the time, 4 ohm rated power was how the different competition classes were organized. Getting the 1 ohm power out of a high current amp was a big deal on the mids and highs in the lower power classes.

Power classes are gone and 4 ohm power is cheap. No need for them. On subs, huge power still means a big transformer and a big transformer still acts like a big inductor (and causes resistive LOSS as well) and a big inductor is still bad for the fidelity of the audio signal.

Bottom line, they're not used in car audio for the same reason that a lot of home audio things are not used: they're not needed.

You dad's McIntosh amps are probably high voltage/low current amps and need the x-former to get any kind of current to the speaker. Having 120V to play with from the wall makes such things convenient.

 

[burro breath 10+ year member]

Stinger and Veritas both used to market Accumatch impedance matching transformers. Once power became dirt cheap, the need for them became about zero. They were great when you were talking about having only 25-50 watts on a channel. The tranformer could be small and the small amount of power wouldn't saturate the core. More power means a larger transformer which means a higher inductance and all the ill effects on the signal that go along with that.
If power is cheap and multicoil drivers are available that can let you wire to pretty much any impedance that you want, and a transformer big enough to work with the power available would trash the sound, why would you want one at that point?

i am not questioning your data(accually i am but anyways)

Mcintosh does make a high output amp with auto formers its 2kw. the only problem is the price, and i do realise it is for home audio, just found it interesting.

http://www.mcintoshlabs.com/mcprod/shopdisplayproducts.asp?hid=1&id=14&cat=Power+Amplifiers&prodid=1115&product=MC2KW