Tube Amp Archive

[quote="tubeswell"]FWIW 220k-270k is a more normal value (than 470k) for output tube grid load resistors[/quote]

Noted. I'll have a try to see how this influences the feel of the amp.

Hi, thanx for the hint / advice about the grid resistors. That solved the problem alright. My amp now works like a charme. !!! I never would have thought that the problem was in that area of the amp. I've been soldering an re-soldering the poweramp, measuring everything there is to measure and pulli...

Hi, I could be on to something here. The ref resistors to ground for the grids are 470k. But... I've noticed I soldered them before the grid caps (so they are between the anode of the drivertube and the gridcap to the pentodes). And they should be attached after the caps (DC blocked by the caps - so...

Screen resistors are 1k / 5 watts.
Grid stop resistors are 8k2.

I don't quiet understand what you mean by 'filtering'.
If you refer to the elco's used in the B+ line: two 32µF/450V elco's and two 22µF/450V elco's. I don't use a filterchoke. It's a resistor: 1k/10watts.

hello, I've got a strange problem in the powersection of my 36 watt. And I can not grasp the reason why it is happening or what is causing it. (man... the houres that I've spend on trying to figure it out....) I've used the schematic that is posted on the site off 18watt.com. The connections of the ...