2014年1月24日 · There is another version with a tone control circuit between the 50C5 and the audio transformer. There is one version that uses both halves of the 12AX7 so the amp has 2 …

2024年12月22日 · I have a Mackie SRM150 powered PA speaker. Two surface mount voltage regulators on the preamp board have failed and the traces have lifted off the circuit board. …

5 天之前 · Greetings : I am fixing up a old record player. Got all the mechanical devices working properly. When played it sounds great but the tone would degrade after a few minutes. I …

2009年12月26日 · I think a 50C5 or 6AQ5 would be a better choice than a 6L6 tube. When I was in high school 40+ years ago I built a 1 tube code practice oscillator with a 50C5 tube. I think …

2023年1月28日 · Hi I built the boost part & add to the complete tone control circuit as in the post 15. Results. I can hear the subwoofer bass.But the problem is I cannot volume even 40%.The …

2025年3月10日 · A pcb made according to the schematic (attached below) uses LM324 opamps. With no input signal to the current transformer pin 3 should be low, and pin 2 follows feedback …

2025年2月3日 · I want to use one centre tap 12 - 0 -12 transformer to power amp (lm1875 stereo) and a small pre amp board but I also need a 5v dc supply. what is best configuration for this. …

2023年1月31日 · I found a lot of conflicting online information about 6550 tubes. Some claim 6L6 is a replacement, wrong pin out. Another place claims triode that is wrong. I looked in my 50 …

2014年3月4日 · I have this inverting Op Amp circuit. When I input a TTL signal which goes from 0 to +5 volts, I expect the output to be inverted and go from 0 t0 -9 volts. What I see on the …

2025年2月25日 · The circuit is programed on an Arduino Uno. The code runs so that when a button is pressed Amp 1 starts playing along with the motor starting. Then, the neopixel rings …