21-10-2023, 09:16 AM
The Rod Pentodes are insanely quiet, with one exception, microphony! Long leads can be the issue as can the way the valve is mounted.
I've wrapped foam around them and clipped the whole assembly to whatever board I'm using, even adding heat shrink to the wires gives a damping effect so microphony is eliminated.
I had microphony on my Pye BB which gave feedback on high volume, carrying out the above was a complete cure.
There is no hum, noise or hiss, checking with my Tek scope it's a clean as a whistle, so is my 3-3 stereo amp with the alleged noisy EF86's I use Telefunken ones.
I've wrapped foam around them and clipped the whole assembly to whatever board I'm using, even adding heat shrink to the wires gives a damping effect so microphony is eliminated.
I had microphony on my Pye BB which gave feedback on high volume, carrying out the above was a complete cure.
There is no hum, noise or hiss, checking with my Tek scope it's a clean as a whistle, so is my 3-3 stereo amp with the alleged noisy EF86's I use Telefunken ones.
