2245 PHONO HISS in right channel...??

skatman

New Member
Does anyone have any experience with noise or hiss coming from one or both channels while on the phono setting? My 2245 powers up nice, sounds powerful and clean, then about 20 minutes/half hour later there is a noticeable hiss coming out of the right channel only. No record playing, it is noticeable when I turn up the volume at any level. This does NOT happen on the AUX in, as my CD player sounds clean and channel is dead quiet. I tried the turntable with another receiver - no hiss.

Anyone have any ideas on what could this be?
 
skatman said:
Does anyone have any experience with noise or hiss coming from one or both channels while on the phono setting? My 2245 powers up nice, sounds powerful and clean, then about 20 minutes/half hour later there is a noticeable hiss coming out of the right channel only. No record playing, it is noticeable when I turn up the volume at any level. This does NOT happen on the AUX in, as my CD player sounds clean and channel is dead quiet. I tried the turntable with another receiver - no hiss.

Anyone have any ideas on what could this be?

Do you mean a hiss or a sort of low level hum. The 2245 (and 2270) will get an irritating low level hum out of just one phono channel if the bottom panel is loose or corroded. It's used as a shield. Try loosening and then tightening every screw on the bottom panel and on the back panel where it attaches to the main chassis. If that doesn't work, then take the bottom off and look around for screws that attach to wires and the chassis. Loosen and tighten everyone of those - especially those that attach to the back panel near the inputs.

DH
 
Hi,
Fred Longworth can probably give you better advice, but I would say that it's probably due to a faulty capacitor or semiconductor (diode/transistor), since it seems to be temperature related.
I don't have the schematics for the 2245 (I am looking for them BTW, if any kind soul has them in PDF format, please PM me), but in the similar 2270 receiver the phono preamp is on a separate small board (P400). Each channel has three NPN transistors and a diode, plus a few capacitors, so it should be pretty easy to isolate the problem (and even easier with an oscilloscope).
Modern low-noise NPN transitors can be substituted without problem, just make sure you have a similar pinout.
 
whsh93a said:
Do you mean a hiss or a sort of low level hum. The 2245 (and 2270) will get an irritating low level hum out of just one phono channel if the bottom panel is loose or corroded. It's used as a shield. Try loosening and then tightening every screw on the bottom panel and on the back panel where it attaches to the main chassis. If that doesn't work, then take the bottom off and look around for screws that attach to wires and the chassis. Loosen and tighten everyone of those - especially those that attach to the back panel near the inputs.

DH

It is a midrange hiss - not a hum. I will check and tighten as mentioned, and see if that helps.

thanks to all of you for the remarks and suggestions... I just bought this thing "refurbished and cleaned" by a "MARANTZ TECH" - don't know what that means now.
 
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