Recent content by Messing with Electronics

People seemed to enjoy my last tube amplifier measurements post, so I decided to do another. I modded this stereo Magnavox 8605 console amplifier to run 12BH7 dual triodes as output tubes, converting it from a single-ended pentode to a single-ended triode (SET) amplifier. I used a schematic by...

I tried something equivalent to this by shorting the input jacks, but unfortunately it didn't lower the noise floor. Yep, tried this as well and there was some difference but not night and day. I think that I remembered to keep the plug in the lower-noise configuration when I ran the tests, but...

Everyone is definitely right about the grounding, and I think the circuit is capable of much lower noise. These measurements were actually taken after I had done some work to address the ground situation, including cleaning connectors, adding tin foil underneath the amp (which is clipped to...

Hello everyone, I am a vintage audio enthusiast who enjoys designing, modifying, and repairing tube amplifiers. I'm also an objectivist and a long-time reader of ASR, but I've always wished there was more tube-related objectivist content on this forum. As we all know, tube amplifiers are far...