In 2026, using the latest Rubycon, Panasonic & Chemi/Nichi-con, these are more advanced than the rest, do not parallell, i e remove the old ones,
only increase capacitance up to the point you see an improvement on the scope, no more! Do not think that overvoltage or overtemp is somehow better, in many cases it is not! Change rectifiers to match surge current. Don't guess, always check & measure to confirm.

Back in the late 70’s I got several of some really nice Sprague NOS 10000uF/100v for about $5 each (from Eli Hefron in Boston!). Proceeded to mount 100kuF of them in a Cerwin Vega A-2200 pro power amp. I guess it improved the bass but, the best part was that at low music levels the amp would continue to play for ~2 minutes after you turned it off!

Back in the late 70’s I got several of some really nice Sprague NOS 10000uF/100v for about $5 each (from Eli Hefron in Boston!). Preceded to mount 100kuF of them in a Cerwin Vega A-2200 pro power amp. I guess it improved the bass but, the best part was that at low music levels the amp would continue to play for ~2 minutes after you turned it off!

Americans amaze me with their attitude ... its known as arrogance in the rest of the world

old men and there believes ... ofCOURSE multiple bigger caps helps always .. aslong as the trafo handles it, and use a softstart .. my amp had 4 x 33k uf sounded amazing, now its even better/relaxter/more dyn amic, more flowing since i put 4 x 180k uf , must say this is a class A amp, so they benefit more from larger caps

Over the decades I've been servicing this stuff, I've found that if a unit that has many components that have drifted off value, it's most likely from a power surge, or especially a lightning strike in the area. That's just an educated guess from experience and circumstances around the particular repair.

Regarding the HF osc, could it be the reduction in ESR at high frequency due to paralleling caps, would one big 4400uf of had the same effect?

I'm also surprised, especially about the oscillation disappearing. The low end stuff seems viable considering only 2000uf

Please forgive me or I can’t see it clearly. It looks like you put the 2 1000 ohms in series and not parallel

For me building DIY amps hum pickup is the biggest issue, worse when you use headphones, star earthing and toroidal transformers doesn't actually work ,I have to trial and error the problem,cutting tracks on my PCBs adding individual earth wires,earthing volume and tone pot casings and shielding over preamp board ,but it's all reduction not elimination, but having casing isolation on your ground side of  input phono sockets made the biggest improvement

Can you use 4kv caps for a power supply? They are ordered in Vars.

Vote amp reactive.

K Var.

I think if you put a film cap across the filter cap it will improve.

yes  but i remember reading something  years  ago,about uprating  power  supply  capacitors    and its about  when in hi-fi history  an amplifier  is made!   and relates to component  costs.   So older amplifiers  i think 60s  70s  maybe 80s too. The cost back then of larger  capacitors,the capacitors themselves  were    much more expensive     per piece   that they are now     So the manufacturers    generaly  used  the lowest value  that would   work.     to save cost.         So with older  amps   there is more room to experiment   with larger  values.    so somewhere along the way  capacitors  became  relatively cheaper    how quick this   happened i dont know      but in modern times  capacitors  are relatively   cheaper,  so manufacturers    were able  use more capacitance  to boost the reserves of the amplifier  so did not do for just enough,but  more to a safe limit.  as the caps  cost  is relatively   cheaper.  therefore  you would need to be more carefull  of increasing capacitance   as  it might already be close to the limit.     So this is difficult  to explain  so i so it another way  any numbers used    will be fictitious.  so i say  the cost  of capacitors  to  build the amp in the late 60,s    is  50%  of the entire amplifier  cost.    But by  1990   the capacitor cost  is 35%  of the total amp cost.       So what the point is  the capacutors in the early days  were more expensive  than today.         I guess the change all moved along slowly    from 60s expensive caps   to 90s cheaper caps.

Insignificant and very possible it’s not even distinguishable. Pure waste of time and effort. My advice, throw it away in the recycling trash bin. Along with all your test equipment

Adding capacitance definitely affects the signal at max power but what about at normal listening volumes?

Increasing filter cap size has always made a noticeable sonic improvement, when I've done it.  The down side is nearly always the power switch.  Particularly with Kenwood, the switches can't handle the inrush current.  When adding filter capacitance, it's important to add a triac switch relay or a soft start.

Did I miss the part where you explained a 20 year old capacitor may have only 50% the rated capacitance due to ageing?

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