Follow-up: Turned on the C2300 preamp and MC501 power amps today and ran tests similar to yesterday. With no signal, on the MC input I got up to about step 64 before noise became audible at 2 ft. from the right speaker, and up to 53 on the MM at the same distance. There is no, I repeat NO sound coming from the left channel. That has been the case with every problem of this type that I've ever had. Today, the noise was more like what I've heard before, with the hum underneath a static-like noise. I also re-positioned the TT power supply to its original spot, on the floor between the speakers; that accounts for the additional improvement, I think, as it had been sitting next to my cable box.
For reference, my standard listening volume is 42; I will go lower or higher depending upon the recording. And I would never be listening at the above test volumes normally; it would be much too loud and I would be putting my speakers at risk, not to mention my ears.
The tubes in the MM are Telefunken Black Diamond ECC83TK, made by JJ; in the MC stage are standard JJ ECC83s.
On a lark I switched to the Tuner and DVD inputs and went up to volume step 62. Crickets, both channels. The noise is exclusive to phono, and to the right channel on both inputs. That doesn't seem a coincidence. It may be time to try cpetersen's suggestion and check the tonearm cable; if that doesn't solve things, then I open the C2300 up and mess with the tubes. I may repeat the tests in mono mode, too.
__________________
SOTA, Grado, SME, Van den Hul, Gingko turntable setup; Pioneer Elite LD, BDP; Sony OLED TV; Magnum Dynalab tuner, antenna; MIT S-video cable; Pangea HDMI cables; DVDO video processor; McIntosh SACD, preamp, power amps; Telefunken Black Diamond preamp tubes; Kimber IC; Transparent IC, PC, SC; Mirage speakers; PS Audio, Shunyata PC; Audio Additives RCA caps; Furman power conditioning; Sanus: racks
|