Rerurn to Romy the Cat's Site
In the Forum: Melquiades Amplifier
In the Thread: R22
Post Subject: Ready to connect a speaker!Posted by JJ Triode on: 1/10/2022
Hi Domidaw, it looks like your amplifier is working pretty much correctly. The plate current in the output tube is a little below the recommended range (180 mA versus 200-280 mA in Romy's diagram) but too low is better than too high and you can adjust it by changing VR2 (monitor voltage at R21 to get into the desired range.) I have no idea what was wrong before.
I can't say anything about your preamp as I am not familiar with the design. The only strange thing is that I don't see a volume control anywhere, but maybe I missed something. Anyway now that you have one working channel, you can connect a speaker to the amplifier, feed in some music and check that you have something recognizable coming out. By the way if you don't have a speaker connected then you should have a "dummy load" (a power resistor of about 8R) across the output terminal of the amplifier.Rerurn to Romy the Cat's Site