Re-Capping Woo Audio WA3

[Capt. Z]

In the past I had 2 caps in my (about 20 year old) Woo3 going bad. I have changed them out, but now I wonder if anyone has re-capped their Woo3 and what caps did you use.

 

[bagwell359]

No, not that unit. However, there are two basic reasons to change caps. The main one is leaky/defective caps - which you did. The other is for sonic improvement (which u may have accomplished to some extent already).

I've recapped and modified crossovers and electronics - due to age sometimes, and sonics at others. While some object, film/foil type caps can be sonically a huge step over more prosaic types - but they are often very expensive and physically large - or huge.

So what types did you use in your recap, what caps did you change, and did you test them for matching capacitance? How many hours has it been on, and what if any changes did you note?

 

[Capt. Z]

The first cap that went bad is located close to the power tube socket. One of the pins had come out of the cap. So I replaced both with some Nichicon Caps that Jamato8 suggested.

Then later on the amp started to get noisy, so I replaced the one cap in the PSU with the exact cap that was in.

So far things seem to be OK, though I can hear a very small amount of noise when no music is playing. I am thinking that may be due to the OTL design, but I am not sure about that.

 

[bagwell359]

The first cap that went bad is located close to the power tube socket. One of the pins had come out of the cap. So I replaced both with some Nichicon Caps that Jamato8 suggested.

Good caps

Then later on the amp started to get noisy, so I replaced the one cap in the PSU with the exact cap that was in.

I'd always replace any paired caps with caps from same manufacturing run - and better yet tested to be very close together - like .1%.

So far things seem to be OK, though I can hear a very small amount of noise when no music is playing. I am thinking that may be due to the OTL design, but I am not sure about that.

You are likely paying more attention - so its possible nothing has changed.

What shape are the tubes in? The transformer isn't a spring chicken either.

I assume you have a multi tester - test everything you can - inputs, outputs, components. Also trying wrapping on different pieces to see if anything needs to be tightened or replaced.

Add: Also to avoid component damage from heat - use radiators to keep the heat from building up on components when you solder.

 

[Capt. Z]

Thanks Bagwell359 for chiming in.

I guess I listen for any 'abnormally' or what I think could be an abnormally.

I am just a basic amateur DIYer with no electronic education. I do have a multimeter and I can check certain things and figure out a few things based just on logic and experience. I also have a B&K 707 tube tester, so I can check and see if a tube is OK or bad. Don't think the transformer have been used to much, since I have several headphone amps and rotate them frequently. Just trying to keep my aging components alive and working well.