I just got a Fisher BA-6000 amp, nice condition, working fine, but I want to change all the cap and improve the sound, power is enough for me.
Any idea how ?
https://www.hifiengine.com/manual_library/fisher/ba-6000.shtml
Any idea how ?
https://www.hifiengine.com/manual_library/fisher/ba-6000.shtml
This unit is 40 years old, so look at all the electrolytic capacitors to see if they
are bulging or leaking. Better, modern equivalents should be no problem to find.
If everything looks ok, and there is no hum or noise, it may be best just to leave it as-is.
It may not have been used very much.
are bulging or leaking. Better, modern equivalents should be no problem to find.
If everything looks ok, and there is no hum or noise, it may be best just to leave it as-is.
It may not have been used very much.
It would probably be ok to increase the uF value a reasonable amount, by say 50% to 100%,
if they will still properly fit the space provided, in both the diameter and height.
The existing capacitors are rated 15,000uF at 67VDC.
Increasing their voltage rating (67V to 100V, etc.) would help them last longer, if available.
if they will still properly fit the space provided, in both the diameter and height.
The existing capacitors are rated 15,000uF at 67VDC.
Increasing their voltage rating (67V to 100V, etc.) would help them last longer, if available.
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Are you kidding ?...Do you have a capacitor meter in the first place? EPCOS, Rubycon, Nichicon, Panasonic...all of them have industrial grade electrolitics...You just need to look for the longest life ones . This amp has very low distortions...You wont be able to hear any audiophile capacitors for supply or decoupling...Just make use of good new ones.The only ones i could recommend for the coupling ones(c03, c05, c19) are the universally aclaimed bipolar Nichicon BS or Panasonic bipolars and i recommend them just because i saw them a lot in the highest grade commercial stuff of the 90țs, the capacitors of the 80țs being simply extinct. Thats maybe the only upgrade you can do to this amp...but i hardly think youll be able to hear a difference against a cheaper brand .Styroflex-copper foil, cog or mica capacitors for c09, c11, c21 and the likes is a known recommendation ...but thats again really tough to prove being an improvement over the original ones cause I doubt Fisher sold an oscillator instead of an amplifier...
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If it were me I would find the output zobels and remove the capacitors, the resistors, or both, thus opening the zobels and ceasing their function. Zobels sound terrible. Doing so may lead to instability and fry the outputs, however.
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You shouldn't give a good advice to anyone if you wanna make some money...You never know how stable is an amplifier even without a Zobel network and if the amplifier is stable enough ...you loose an "audiophile " client 🙂 If it's not..."it was just some old crap amplifier that burned out after 40 years of service" ...
I 'll note that I never claimed it was good advice, just that it's what I would do, and that it would sound better than it does now with minimal screwing around. Unless it dies, a possibility I also communicated. 🙂