Transformers....smaller, lighter, better... Is it possible?

[FunkyE9th]

Just curious... It seems bigger, heavier is "better" is the common accepted standard when it comes to transformers. Are there transformer designers out there trying to go smaller, lighter is "better" or for that matter, just as good. Yeah I know..."better" when it comes music is very subjective, but just play along...

With speakers, you got the neodymiums. Then you also have smaller electrolytic caps. So I'm wondering... Are there transformers designers out there pushing the envelope trying to get better designs at a smaller, lighter package?

[jaysg]

The latest Crate V18 has a switching power supply...supplies I guess, therefore no PT.

[FUCHSAUDIO]

Some of the better transformer designers can pack a decent amount of current in a small package, and keep it cool. Sergio at Mercury Magnetics does this well. There's a practical limit to how small, before you run out of space for the number of windings, or the core becomes too small and heats up.

As far as output iron goes, you need a good core size for good bass coupling, and that cannot really be avoided. And no, toroids don't work well as outputs (imho) nor would they save any space.

[Structo]

After installing the beefy Prosonic OT in my D'Lite I noticed it had more girth and bottom end than the smaller open frame type Brown Note Heboer OT that was in it.

Now I need to adjust some couplers and bypass values to knock some of the bottom down.

But I think I will like it this way better. After running the amp at pretty high db levels the new end bell type OT was cool as a cucumber.

[Phil_S]

Transformers and not required. Look at this:
http://www.vikingamps.com/

[M Fowler]

It would take a lot of diode/capacitor/resistor strings to provide all the various voltages.

Mark

[FunkyE9th]

Thanks guys for chiming in. The Viking amps sounds like cool design. I like how he came up with the idea of not using transformers... need a lighter amp due to back problems, design an amp with no transformer.

[D-Day]

need a lighter amp due to back problems, design an amp with no transformer.

LOL, I had to move The Widowmaker last night. Ampeg VT22. My back is really singin the blues today.

[M Fowler]

There have been lots of transformerless designs over the years for things like battery chargers and other projects. Mostly lower voltage though. I don't why he desided to go this way.

Mark

[FUCHSAUDIO]

Output transformerless (OTL) tube amps have been around since the 30's. Problem has been that they are very inefficient, compared to conventional tube amps, which are themselves, not very efficient to begin with. A 100-W OTL amp sucks up over 3000 watts of energy !

Many feel that part of the tone and feel of a tube amp for guitar IS the output iron saturation. Most OTL designs exceed the duty cycle of their output tubes when driven into clipping as well.

While I'd be curious to know what makes this circuit tick, I tried making a OTL guitar amp in the 80's, and other than stellar cleans, they don't really prove themselves viable imho. There have been a couple of other designs for OTL guitar amps too, although I forget the makers name. One guy was in Minnesota I believe. I think they haven't caught on for a reason...

[chromaticdeth87]

from Electronics: Applications and Concepts (1995): "Most engineers prefer to use voltage doublers, or even quadruplers, to attain a variety of voltages throughout a circuit. Transformers are too large and bulky for some designs and often need to be isolated far from other sensitve devices within a piece of equipment."

Pretty interesting but they are probably refering to smaller applications like cell phones and toasters. But, you never know.

[jaysg]

The Music Man HD-65/130 amps use a voltage doubler for B+, but power is power, so I don't think those PTs are much lighter weight than the next.

[FUCHSAUDIO]

Actually, they can be a little smaller than a non-voltage doubler transformer, but not by much. Power is power. If it's voltage, current, or wattage, it has to come from someplace.....can't really cheat the hangman....The MM's bias up low (20 or 25 ma per tube), since the plate voltages are high, and the screens low, you run a little less current. BUT: To make the wattage, you need either voltage or current, but it ain't a free lunch...

[Merlinb]

Just curious... It seems bigger, heavier is "better" is the common accepted standard when it comes to transformers. Are there transformer designers out there trying to go smaller, lighter is "better" or for that matter, just as good. Yeah I know..."better" when it comes music is very subjective, but just play along...

It is entirely possible to make remarkably small transfomers, but until there is a breakthrough in core material you're stuck with the same old metal they've been using for years, and the good stuff is EXPENSIVE. Sure, you could make a nickel core toroidal, but the cost gets extortionate.

[drz400]

Switching supplies are the only way to drop the weight.
As Mr Fuchs says, you are dealing with VA rating on transformers, you really cant cheat with doublers etc, it isnt going to save you anything. If the transformer is smaller than it should be it will get hot, hum or fail. OR all the above

http://www.acopian.com/store/productdet ... :+Y3,i1584

They are typically around $85 for a custom unit, not much needs to happen afterwards except your other filtering.

I haven't tried one but have had great success with switchers for heaters.