Fourier Amplifiers What Is The History and How Reliable

Atmasphere would be a better bet.

The Fourier, like all OTL tube amps, should only be used with autoformers. They are stressed when driving loads below 8 ohms. I have three Futterman amps. Autoformers let OTL amps see a  constant higher-impedance load.

Happen to be considering a pair of Fourier Panthere amplifiers and am wondering what the history is on them. Supposedly these are some of the last production models and are more reliable than previous versions.

Do yourself a favor and stay away from them. We serviced (or tried to) some of the fourier products and ran into serious engineering issues. One example: the rather questionable filter caps used in the power supply were run about 40 volts **above** their marked rating! This results in their exploding. Before I figured this out we had one of these amps on the bench. At one point when I looked away from it one of the caps on the power supply board exploded and embedded itself in a dropped ceiling panel. I’m glad it didn’t hit me in the face but my ears were ringing for ten minutes. It made a mess.

I regard it as unethical to service these amps unless problems like that are sorted out. This is simply because they can’t otherwise be made reliable, and the cost of fixing the engineering bugs is more than the purchase price. If a person had one of these and didn’t experience this or other problems he is a very lucky person and should have invested in the lottery instead.

Now it is true that I am associated with Atma-Sphere which is the largest and oldest OTL manufacturer worldwide. But Fourier was already out of business when this anecdote occurred and that was a good 20 years ago. It was their reliability issues that drove them out IMO. I don’t care what amp you get, just don’t get a Fourier. If you google my posts on this and other websites, you’ll see that I’m not in the habit of badmouthing other’s products. I make the exception for this one because so many things were problematic with them. In a nutshell the purchase price is only the tip of the iceberg.

Like I said...

I’ve got a vintage English roadster (‘55 Triumph), and the engine is half apart now.  But after working at a computer all week, I don’t mind getting greasy.  I would have to take anything electronic to a skilled repair shop.  So for me, it sounds like a Fourier might be worse than a vintage English roadster - except maybe in the rain