Bwaslo,
Great amp! Just ran across this now - funny I am making something kind of similar and even thinking of similar case and also using SMPS. You are a lot father along though.
How much power can you get into 8ohms at less than 0.5%THD? And can you please show a spectrum of the harmonic distortion?
Great amp! Just ran across this now - funny I am making something kind of similar and even thinking of similar case and also using SMPS. You are a lot father along though.
How much power can you get into 8ohms at less than 0.5%THD? And can you please show a spectrum of the harmonic distortion?
Hi xrk,
The one using a 36V LED SMPS (mono, one channel per chassis, four output devices per channel) can do 55W, maybe 60W @ 8 ohms before it gets to a half percent. At that point, third harmonic is about even with 2nd harmonic and the higher ones are starting to pop up (onset of clipping).
I didn't save any spectrum plots of that, but the character of all of them are pretty similar. Here are from the v1 Spring amp at 1W and 20W
The 2nd Spring is a little cleaner that that, but not greatly.
The one using a 36V LED SMPS (mono, one channel per chassis, four output devices per channel) can do 55W, maybe 60W @ 8 ohms before it gets to a half percent. At that point, third harmonic is about even with 2nd harmonic and the higher ones are starting to pop up (onset of clipping).
I didn't save any spectrum plots of that, but the character of all of them are pretty similar. Here are from the v1 Spring amp at 1W and 20W
The 2nd Spring is a little cleaner that that, but not greatly.
The LA article has some, but this is a slightly enhanced version and it may measure a little better. In the article Bill says, "At 20Watts out, SPICE says 0.23% still with 2nd harmonic highest, though upper harmonics are climb- ing up as clipping is approached. Measurement agrees pretty well."
Bill beat me to it! 🙂
Bill beat me to it! 🙂
Looks very nice FFT. As expected around -60dB H2 and lower H3 and almost nothing else at 1W. I bet it sounds wonderful.
- Status
- Not open for further replies.