Marantz 2220: Need help troubleshooting hiss

[Broken_amp]

@Aaron99 also wondering if you managed to fix the hiss. I'm experiencing the same problem on my Marantz 2215. I've replaced all the 2SC458s on the P500 board with KSC1815s as recommended on this forum but it's still hissing.

 

[Broken_amp]

@Aaron99 I'm curious if you ever figured your hiss problem out.

I have a 2220 that I've replaced all the ecaps with quality ecap replacements or film caps on the p800, p500, p900, and main ripple filter. I've also replaced the 6 2sc458 transistors on p500 and 2 on p900.

I've had the same hiss symptom as you, although curiously, I also can't seem to visualize it on my scope's fft. It's possible the white noise is uniform enough that it's just the noise floor without any peaks.

I hear the hiss through phones and speakers, even when the volume knob is at zero. To prove to myself it's p500, I added preamp outputs tapped off of the output of p500 and I hear the hiss on a totally different amp.

I've paused my recap work while I dig into this issue. At this point, I only have p700 and the DC coupling caps left to rework.

Hi there, just wanna know if you ever figured out what was causing the hiss @Evandozier . Happy New Year!

 

[Aaron99]

I did not ever find out the cause. The 2220 went back on the storage shelf to be looked at another day...

 

[marantz1974]

I've had hiss in the 2245 transistors were the problem. My marantz 7t has little hiss but haven't dug into it. Like how it sounds prob normal amount

 

[Broken_amp]

I've had hiss in the 2245 transistors were the problem. My marantz 7t has little hiss but haven't dug into it. Like how it sounds prob normal amount

Was any specific transistor the culprit? I've replaced 6x 2sc458 on the P500 board and 2 more on the P400. Hissing is still there unfortunately