Whoa....
Hold on.
There are two types of caps in this unit: signal path caps and filter caps.
The large value caps ur talking about now are filter caps. The values on the can (package) of the caps are the size of the cap, in ufd (microfarad or also MFD) and voltage rating. Your voltage found should be LESS than the voltage rating of the caps. Seems fine so far.
There is NO NEED to change ANYTHING AT ALL until you tell us A) does the thing work now? If not WHAT does it do? and B) have you changed the tubes?
RE-SEAT the tubes in their sockets - sockets often are intermittent due to oxidation on the pins of the tubes AND the socket itself!!
Of all the things that die the tubes are high on the list. Caps second, and far behind.
You will want to probably change out the rectifier. It is a "bridge rectifier" (look it up, google if you need to). The package for the one in there is very different than a modern one. So you will have to make it fit and work in the space. You want a 1000piv bridge, and something from 1amp up... 10amps or better seems nice. Cheap too, they are not expensive. BUT if that one works, there is no need to change it immediately.
How to know if it works? Measure the voltage IN (remove one leg that goes to one of the terminals marked " ~ " - there are two so marked ) and then use an AC meter (not ur fingers) to go between the two wires, one still on the ~, the other floating. See what the voltage is. Now you can go find the formula that tells you what the DC voltage OUT of a bridge with a "capacitor input filter" is expected to be. You should find THAT voltage on the ouput side of the bridge, or on the first filter cap.
IF you do not find that voltage or nearly so, then you likely have a fault either in the cap or the bridge or both. A shorted or leaky cap will show excess AC on the line that should have DC, so you can measure both AC volts (high voltage) and DC volts (or "ripple"). DC ripple should be <10% of the AC volts or LOWER. Actually 10% is highish. BUT GOOD ENOUGH TO MAKE AN AMP HAVE SOUND!!
Now you are starting to troubleshoot. You do this stage by stage - check voltages on all the pins of the tubes, write them down, compare to the suggested voltages found in an online tube manual. They should be close. Pay special attention to the grid voltage and plate voltages.
Of course you didn't say if you tried to make sound with this unit, and if you did what if anything it did or what you heard... so it's hard to know where to point you.
Again, CHANGE NOTHING until you have some facts. Ok, you can change the tubes. That's ok. But nothing else yet.
_-_-bear
PS. for example, you turn it on, and it makes no music, BUT you turn the volume control and you hear "scratchy" or "static" sound... etc...
