Rerurn to Romy the Cat's Site

I took today the “Little Amp” at my client’s site and was listening it today during the operation time. I detected something very interesting behavior.

The 6C19P that I put into the “Little Amp” are well-selected, equal gain, no microphonics and well burned-in. However, when I was listened I did detect some very minor microphonics. I was very surprised but then I did detect what was the problem.

I use the tubes cooler on the 6C19P – completely unnecessary things but I had them and I put them into the use. The fan part was that the 6C19P with the cooler did behaved microphonicly but without the cooler they were absolutely quite. I did a bunch of experiments, trying to find the relationship between the position of the cooler and the microphonics but was not able to detect any pattern.

I wonder if a tube radiates any magnetic field that makes the fins to vibrate? Or perhaps the cooler fines react to some other magnetic field? Aren’t the cooler fines should be made from a material that should be immuned to this behavior?

Rgs,
The Cat

Rerurn to Romy the Cat's Site