It's a matter of linear headroom. What happens in a feedback type phonostage is that a tic or pop will drive the circuit out of loop (loss of feedback control, sort of like clipping), which it then has to recover from. As a result, high frequency overload conditions are greatly exaggerated. Worse yet, is that when open loop, there is a corresponding loss of all other musical information. The BUGLE is designed to amplify the tics and pops as they are, yet not go open loop, the music continuing in parallel. Of course, there is a limit to this, where the BUGLE will eventually clip. The CORNET achieves the same thing, but has much softer clipping during overloads.
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