I have just bought an used Krell FPB 600 big amp. It was the product of year 1997. My first impression is that the amp does not sound very dynamic and not going to deep bass much.
I opened the cover and all electrolytic caps looked OK, no leak no deform. Of course I cannot tell if those caps are still in good condition or not.
Is it worth replacing all the electrolytic cap at this point. Does it bring back the dynamic to the amp if I replace all the caps?
Need ypur help
I opened the cover and all electrolytic caps looked OK, no leak no deform. Of course I cannot tell if those caps are still in good condition or not.
Is it worth replacing all the electrolytic cap at this point. Does it bring back the dynamic to the amp if I replace all the caps?
Need ypur help
Have the caps measured by a technician for value and ESR.
Replacement with suitable, quality caps will be costly, regardless.
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I doubt it will 'improve' the response as it is DC coupled.
Have a look at the service manual, there are only low value anti parasitic capacitors in the signal line.
Have a look at the service manual, there are only low value anti parasitic capacitors in the signal line.
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I would have a tech check/set the bias for starters.
Only caps in the signal path are two back to back electrolytics in the servo, probably not going to cause much harm on their own. I just replaced some that are that same value in a similar position with some Elna ars.
As for what you are noticing sound wise, I would maybe look elsewhere in the system perhaps.
Only caps in the signal path are two back to back electrolytics in the servo, probably not going to cause much harm on their own. I just replaced some that are that same value in a similar position with some Elna ars.
As for what you are noticing sound wise, I would maybe look elsewhere in the system perhaps.
I purchased this KRELL FPB 600 amp from the previous onwer who kept the amp on standby mode(around 80 watt power consption) when not in use. It means that the amp's electrolytic caps were all slightly charge/discharge. From year 1997 until now it is 22 years, 22years x 365days x 24hour-a-day = 176660 hours, while the caps rated at 2000hour lifespan under 85degree C. I measured the temperature of the surface of the cap during using it for 3 hours and the surface temp of the big electrolytic caps were almost 60degree C.
Are those caps aging already causong the dynamic reduction?
Are those caps aging already causong the dynamic reduction?
There is nothing to set/adjust as far as the bias is concerned. Little chance an average tech would make head or tails of the biasing arrangement anyway.
Never really liked the FBP series. A cap upgrade will certainly improve some aspects of the sound but likely not what the OP perceives as deficiencies.
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