I recently picked up an all original early '70's Maestro Echoplex EP3 and it seems fairly noisy. I do not have any previous experience with one so I do not know what the noise shelf is on these. The noise is not bad on a clean tone but you know it's there and when cranked its definitely very audible. Dirty tones and its fairly prominent even at lower volumes. I cleaned and demagnatized the heads, adjusted the vol pot for the lowest noise, cleaned rollers, and put in a new Orbit tape cartridge. Everything else is original and it runs and sounds great. Switching the echo on and off makes no difference in the noise level shelf. Are these units inherently slightly noisy or is there something I can do short of sending it off to a pro. Thanks for any help!