Fisher CA-880 goes BAAAAAHHHH!!!

[keyboarder]

I have a Fisher CA-880 that when powered on makes a very loud noise/hum sound. I move speaker to B and it does it there, move to A and does it there.

It's not blowing fuses so I don't know if it's the STK issue I've read about others happening.

Why are these so cheap on ebay? Reliability issues?

I thought with it being 400W and a 2 channel amp you could put 200W per side, but I guess you have the A and B speakers so it's only 100W per speaker.

 

[wlgrant6]

This unit is rated at 100 watts per ch ( times 2) rms @ 8 ohms. Don't know where the 400 watt figure came from. Believe this might be a bit overrated
as it uses 80 watt Sanyo ckt packs. Can't believe they are pulling an
additional 20 watts per ch out of the preamps.

Most of the problems in these units is in those Sanyo ckt packs (the whole
thing was made by Sanyo), but it would be a little strange for them to be
causing the problem you are having.

Good Luck

 

[larryderouin]

keyboarder: If you're looking at the back panel and it says 400watts there, that is the TOTAL WATTAGE LOAD of the unit on your electrical system in the house, when it's running FULL BORE at Maximum draw. NOT WPC.

100WPC is into 2 channels @ 8oHms. With the SANKEN chips as outputs don't expect much more than 5-10 watts more @ 4oHms on ONE SET OF SPEAKERS. The "A" and "B" speaker positions are switch positions NOT AMPLIFIERS. The speaker positions are connected to the same output point on each amp via the switch. And when you put them both online the oHms DROP! Running 4 speakers at the same time is DANGEROUSLY UNHEALTHY for them, UNLESS ALL are 8oHm. 4-8oHm speakers would be something like 5 ohms. 2-8's and 2-4's would be about 2.5oHms. and 4-4oHm speakers is something less than 2 ohms. ABSOLUTELY FATAL for these amps.

Rules for Running speakers on SANYO (FISHER) CHIP AMPS. NOTE: This would apply to all amplifiers running STK MODULES (Pioneers, Sansui, Kenwood, whatever).
1.) You can RUN ONE (1) PAIR of 4 oHm speakers at a time. NEVER TWO(2).
2.) DO NOT MIX 4oHm and 8oHm speakers....EVER....PERIOD.
3.) 2 pair of 8ohm are OK, up to a point. Don't Crank them over 1/2. It won't get louder, but distortion WILL GO UP as will the HEAT from the STK Module.
4.) If it starts getting hotter than normal (barely warm or what ever your norm is) TURN IT OFF NOW and remove all speakers except one pair. and plan on getting new Chips and capacitors.


Larry

 

[keyboarder]

Great info, thanks. I didn't realize Fisher was Sanyo. I have a Sanyo JCX-2600K that I love. To me it's right there with my silver face Pioneer, Yamaha, MCS and Marantz receivers. It must be that era.

You're right, I was reading 400W on the back so that makes sense that it's only 100W per channel after reading your explanation.

This Fisher is one rugged, heavy unit that I'd love to save but it sounds like it might be more than I am willing to take on right now. I'll set it aside for a day when I have more electrical repairs under my belt.