Speaker and amp matching?

SamyBoy13 · 30 Aug 2017 at 15:17

Hi there guys I recently got a Fisher Ca-224 amp and monitor audio br1 from a carboot sale from two different sellers. I paid 30 pounds is total for the set. However I haven't realised that the speakers are 6ohm whereas the amp is rated at 8 ohm only 2x35 rms.

I connected them up together and at 20% volume they sound impresive and loud enough with no distortion or hissing. However I'm worried that through not matching the impedancesearch, I will break either or both.

Any advise would be appreciated
Thanks Sam

Fisher CA-224
Integrated Stereo Amplifier 1986

Specifications
Power output: 35 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 20kHz

Total harmonic distortion: 0.5%

Damping factor: 20

Input sensitivity: 2.5mV (MM), 150mV (line)

Signal to noise ratio: 68dB (MM), 85dB (line)

Dimensions: 400 x 91 x 202mm

Weight: 4.1kg

Year: 1986

SamyBoy13 · 30 Aug 2017 at 15:32

Any ideas how much would that cost as I'm not able to do it myself. Also any risk associated with bad capacitors?

SamyBoy13 · 30 Aug 2017 at 21:49

I opened it up and this is how it looks. When I connected them to br1 to see if it works. I was surprised as the denon dab 37 I got roughly 1 year ago, makes hissing noise all the time and this old amp dead is silent.

Sometimes I wished I knew how to fix electronics.

SamyBoy13 · 31 Aug 2017 at 01:40

Okay. Out of interest what is the worst case scenario when a power capacitor decides to blow up. Also if other smaller capacitors blow up could they potentially damage br1?

I don't mind service the entire amp but I'm not sure how much the amp is worth. It's only 2x35 rms into 8 ohm so probably it isn't work that much. Although I'm not sure.

Further, in all fairness the amp costed only 5 pounds and speakers 25 so I don't want to pay really 70-100 pounds to replace most of the caps as for additional 50 I can get new denon dab 40 with 3yrs warranty and peace of mind that if it breaks it will be fixed free of charge.

SamyBoy13 · 31 Aug 2017 at 23:26

Thanks a lot for your post KEI. I may give it a try. Any tips on how to test transistors, resistors, caps etc.? The only thing I have is a multi meter and soldering iron so not sure if I will need anything else, except the parts.

The only other issue I noticed that only CD red and white input works as other make makes crackling noise form speakers. Otherwise, the speakers play exactly the same as connected to my denon 37dab (At least I cant hear any difference with BR1s)

I have to admit I love the style of this amp, even though it's older than me