Question about caps in my Kay 720

[Regis]

I am going to recap my Kay 720, and am a little confused about the designations. None of them are marked on the schematic for the type. All of them have some kind of marking on one end. The cap can I understand, the rest not so much.

There is a .47 can which I assumed is an electrolytic, but I can't find one of that value. It's location in the power supply leads me to believe it is an electrolytic. Is it indeed? If I can't find one that value what should I use? I've marked it in green on the schematic.

The others look like I could use Orange Drops or Mallory 150's but they are marked on one end? I've marked them in blue on the schematic.

Thanks guys

Regis

[soundguruman]

The .47 is not an electrolytic, it's just a bypass cap. The marking is the outside foil.
You should replace the 20/20/40/40 electrolytics, and the/.47 first.
Then test it.
Replacing the rest of the (de-) coupling caps may be totally unnecessary.
You may find that the amp sounds better with the old ones.
We do not "just" replace everything. The electrolytics, OK. They fail first.
We leave the vintage caps, because that's what makes it sound like an old amp.
You are taking all the vintage out of your vintage amp.

[Jazz P Bass]

Regis, the caps with the band are all coupling caps. Non electrolytic.
I believe the banded side was called the "foil end".
There is an awful lot of mojo myth on that term.
Any good non e cap will do.
As to the 0.47uf cap, that is also non e.
I was taught that in filtering, "the big caps take care of the big stuff & the little ones take care of the little stuff".
So maybe it was added for a little extra spike suppression.

[52 Bill]

There is a .47 can which I assumed is an electrolytic, but I can't find one of that value. It's location in the power supply leads me to believe it is an electrolytic. Is it indeed? If I can't find one that value what should I use? I've marked it in green on the schematic.

No, it's not an electrolytic. Electrolytics are just caps like any others, but their makeup is such that they are best for large value caps, let's say for values above 1 or 2 uF. It's all just a matter of size and economics. Use any cap to replace it.

The others look like I could use Orange Drops or Mallory 150's but they are marked on one end? I've marked them in blue on the schematic.

Some caps were marked with stripes to denote the side of the cap connected to the outer foil.

[soundguruman]

The "outside foil" is the stripe end. It's not a myth.
It's important for signal to noise ratio and distortion.
Back in the days of real craftsmanship, it was really important.
Nowdays, when amps are made in China, noise and distortion are ignored.

[g1]

Apparently the hogwash rectifier is still on holidays. Time to update my sig.

[Regis]

Awesome, thanks guys. I like the tone of the amp the way it is, so I'll leave it in. I am ordering a new cap can.

One more question if you please, there are a 10k and 22k resistor in the cap cap area, I wonder what wattage rating they are? Looks like the 10k is a three watt or even larger? I've attached another pic.

Thanks again

Regis

[soundguruman]

It's better to mount the can with a capacitor clamp.
Instead of trying to solder it to the chassis.

[soundguruman]

Apparently the hogwash rectifier is still on holidays. Time to update my sig.

What's that supposed to mean?

[52 Bill]

One more question if you please, there are a 10k and 22k resistor in the cap cap area, I wonder what wattage rating they are? Looks like the 10k is a three watt or even larger? I've attached another pic.

To me it looks like the 22K is a standard carbon 1/2 watt and the 10K is a 2 watt.

[Regis]

To me it looks like the 22K is a standard carbon 1/2 watt and the 10K is a 2 watt.

Thanks Bill!

[Regis]

To me it looks like the 22K is a standard carbon 1/2 watt and the 10K is a 2 watt.

Thanks Bill!