Ribbon poweramplifier

[Lgrau]

Hi,

I've made some tweeter ribbons with an impedance of 1Ohm.

I like to avoid transformer, so want to check if there's some easy to build amplifiers out there?

I assume the voltage doesn't have to be that High.

Actually I was planning to use a opamp with a single driver stage behind. But want's to check for other ideas.

I assume a current amplifer would also make a good job here. The crossover is done in the digital domain, so no need to consider this.

[geraldfryjr]

Here is something that I came up with the other day,

QUASI Amplifier for Beginners

Although I haven't built it yet,it does simulate pretty good.

jer

[tinitus]

heat will be alike classA

[geraldfryjr]

Yes very much so at 1 ohm as the current out will match the voltage out.
I haven't tried it yet in the sim,But logic tells me to double up on the output devices for a 1 ohm load.
Although a 66Vp-p swing is a lot of power at 544.5 watts into 1 ohm.
I was also able to set the bias pretty high for class A operation as well,as it is just a sim for now.
I do plan on building this one some time.

jer

[a.wayne]

Hello,

Read through this for a start ...

Apogee Scintilla amp


opamp ...

[tinitus]

Originally Posted by a.wayne

Hello,

Read through this for a start ...

burning amp BA3 would probably do it

[a.wayne]

Burning amp is about right .....

[Lgrau]

Hi,

Thanks for all the posts.

I would really prefer if it's not a classA, since I want a build in amplifer. I guess the powersupply could be placed seperatly.

Another important parameter is that there should be no, or very little voltage offset at the output.

Seems like opamp with buffer, is not seen as good solution, any specific reason for it?

but anyway, it's only needed to have a gain of 1x if a poweramplifier is used. Any good idea of stage to add to the poweramplifier in order to reduce the load, seen from amplifier?

[godfrey]

Originally Posted by Lgrau

Seems like opamp with buffer, is not seen as good solution, any specific reason for it?

Sounds OK to me, as long as you're not of the "all opamps sound lousy" mindset.
At least it's a (relatively) easy way to get something up and running. You can always swap the "opamp" part of it for something discrete later on if you feel the need, and keep the buffer part of the original.

After all, the big money normally goes to the power supply, heatsinking etc. The small-signal stuff is relatively inexpensive.

One thing though: I would use a separately filtered/regulated supply for the opamp as the output buffer is likely to put a lot of ripple on it's supply rails.

[woody]

There was some discussion about this on Audiocircle. At least one of the designs
used the IXTH20n50 the same device used in the Zenlite but used it in a self biasing
circulotron output stage.


Two simple Current Amplifiers for low impedance loads