Step-up ...

[Jay Bala]

Has any of you ever ran into step-up transformers for converting headphone output (usually in the 30 to 600 ohms) impedance to a 4 ohms?

Regards,
Jay Bala

[Pelliott321]

I believe they are called autoformers
a lot of people use them on olt amps to present a higher impedance to the amp if they have lowe impedance speakers
I assume they can be used the other way around. the guy from anticables makes a version I am sure there are many other brands out there

[brombo]

Why?

[Pelliott321]

I was not about to answer his request with another question, but I wondered that too
Maybe he eats peanut butter for lunch instead of driving to work

[SoundMods]

I've used auto-transformers when I was using my Acoustat electrostatic speakers. Once I realized that they were not interested in current at their 4-ohm nominal impedance -- using the transformers hooked up to the 4-ohm taps of my then tube amps and driving the speakers off of the 16-ohm transformer taps was an eye opener. Instead of straining to drive the Acoustats, the amp. just loafed along and filled the room with some big sound if I wanted it big. Very Cool!!

[brombo]

Headphones take so little power impedance matching is not required unless you are talking about electrostatic headphones which require significant voltage (not power) to drive. However, electrostatic headphones would come with a matching transformer.

[Jay Bala]

I thought I could get a headphone amp to drive 4 ohm super tweeters if I can get them to drive 4 ohms impedance.

[Pelliott321]

Probably not enough power

[brombo]

Depends on the headphone amp and the tweeter efficiency. Back in the 1970's I used a SWTP Class-A headphone amp to drive Altec 3000H horn tweeters and it worked fine in a tri-amped system. No transformer required.

[Jay Bala]

Depends on the headphone amp and the tweeter efficiency. Back in the 1970's I used a SWTP Class-A headphone amp to drive Altec 3000H horn tweeters and it worked fine in a tri-amped system. No transformer required.

No impedance mismatch? No damping factor issue?

Tweeter is 104 dB/W using it from 5K to 50K. I am thinking 1w should be enough.