When I first got mine, it would make this unbearable crackling sound, even with very low-gain signals. Two things I remember doing before the crackling was gone was changing the tubes, and installing an external spring tank.luchog wrote:My R-56 is the same way with sensitivity. Even with input and feedback way down, waving my hand anywhere near the tubes causes noise and alters the sound profile. I kind of like that, actually.Neither wrote:I've got two R-56's and they both are completely different. The 1st one is EXTRA SENSITIVE. Even just waving my hand near the tubes can change the sound. The feedback is uncontrollable even with feedback near zero but it helped when I muved my rack further from my monitors. The monitors are magnetically protected so I guess the feedback was from acoustic vibration affecting the tubes and the springs.
As I have it now, it doesn't crackle at all, even at high gain settings.