Zobles don't just help with reactive loads - they can also help amps that oscillate even without a load, due to rising output impedance with frequency.
Even if you do get the amp stable, you might still not have enough frequency compensation in the Vas. You should check the amp with a square wave input and add enough compensation to remove any ringing. It might slow the amp down a bit, but it's worth the sacrifice.
Even if you do get the amp stable, you might still not have enough frequency compensation in the Vas. You should check the amp with a square wave input and add enough compensation to remove any ringing. It might slow the amp down a bit, but it's worth the sacrifice.
Well, here's the crunch. As I said a few times: the amplifier will oscillate like that into a 4 ohm resistor. Therefore, there is no rising impedance with frequency.
Anatech: Yes, it is a bit painful of a thought slowing it down... Then again, I have tested this amplifier at 200Khz with less than 1db down at full power on resistive loads. Therefore, I'm not worried about losing a bit of frequency range.
Anyway, I am testing with square waves now that I got it to quit oscillating. I'll get back to you guys on that when I've got some results.
Anatech: Yes, it is a bit painful of a thought slowing it down... Then again, I have tested this amplifier at 200Khz with less than 1db down at full power on resistive loads. Therefore, I'm not worried about losing a bit of frequency range.
Anyway, I am testing with square waves now that I got it to quit oscillating. I'll get back to you guys on that when I've got some results.
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