Hello,
I'm new to the forum but not new to Bottlehead. I built a first-generation Foreplay many years ago. In the meantime I've built a few PTP designs of my own and a few I found by other people. My Foreplay's power transformer died and my choke-loaded 5687 preamp's regulated heater supply died so I was listening to a solid-state NAD pre. That prompted a Quickie (how can you resist?). The problem: it's got some kind of oscillation or at least a constant thumping noise at a consistent frequency in both channels. At first I thought it was something wrong with the PJCCS so I replaced with Hammond 156Cs. No change. I checked and rewired the ground scheme. No change. I have the grid stoppers installed. Any thoughts? Larger grid stoppers? It's not horrible when the music's on, but I'm currently using it to drive my headphone amp. It's not tolerable directly into my ears.
Alan
I'm new to the forum but not new to Bottlehead. I built a first-generation Foreplay many years ago. In the meantime I've built a few PTP designs of my own and a few I found by other people. My Foreplay's power transformer died and my choke-loaded 5687 preamp's regulated heater supply died so I was listening to a solid-state NAD pre. That prompted a Quickie (how can you resist?). The problem: it's got some kind of oscillation or at least a constant thumping noise at a consistent frequency in both channels. At first I thought it was something wrong with the PJCCS so I replaced with Hammond 156Cs. No change. I checked and rewired the ground scheme. No change. I have the grid stoppers installed. Any thoughts? Larger grid stoppers? It's not horrible when the music's on, but I'm currently using it to drive my headphone amp. It's not tolerable directly into my ears.
Alan