If you're reading this, you've probably noticed that when you boost any frequency band in the HQ App above a certain level (about 3dB), the overall volume will start to decrease, and you may be understandably confused by this phenomenon. This is a feature of the Digital Signal Processing (DSP) in Penrose called Automatic Gain Compensation (AGC), and its purpose is to eliminate the overload distortion that would naturally accompany large boosts in equalization (EQ). Rest assured this is totally normal and all you have to do is increase the headphone volume by spinning the Headphone Volume Wheel up a few clicks. This way you'll get the benefits of your EQ adjustment without the distortion you would otherwise get from those boosts, so you can have your cake and eat it too!
To explain a bit further (warning, nerd-out alert):
Anytime you boost a given frequency range, you obviously make the signal louder in that range. What that means for an amplifier is that if the signal was already at or near the maximum level the amp can handle, the boost in those frequencies can push the amp above its limits and into "clipping" where it will start to distort. The more you boost, the more the amp will distort.
Since the amp circuit in Penrose is running at high gain for the best signal/noise ratio, boosts in EQ must naturally be compensated for to eliminate the possibility of distortion, so this is the reason for AGC in the DSP.
Audio engineers are very familiar with the technique of gain staging. They know from experience that boosts always come with a cost, and they must reduce the gain in some way to compensate, or risk unwanted distortion.
To be completely truthful, there are two ways to accomplish similar goals when it comes to EQ in Penrose. The first way is the AGC process automatically applied when you boost frequencies (known as additive EQ with active gain compensation). The second way is for you to reduce what you want less of instead of boosting what you want more of, also called subtractive EQ. The advantage of the subtractive approach is that you don't have to compensate the gain as much since you're not in danger of clipping the amp stage. The two approaches will sound different of course, so we encourage you to experiment to find the best solution to your ears.
We hope this helps explain the purpose of AGC, and why it's needed in Penrose. If you didn't find the droids you’re looking for here, please contact your dealer or email us at firstname.lastname@example.org, and one of our friendly support reps will get in touch as soon as possible.