"robobass" wrote ...
I am trying to copy a preamp circuit for an electrostatic transducer
pickup so I can make it stereo. It looks very simple, but there are
two little white blocks I cannot identify. One has a logo I don't
recognise and a number 022J400.

What I see in the photo is actually ".022J400"
It appears to be a capacitor with a rating of 0.022 microfarads @ 400v

The other says only 68nJ63.

Most likely 68 nanofarads (0.068 microfarads) @ 63 volts

Are they capacitors?

Yes. And relatively common ones that should be available in
many places.

If you want to see a jpeg, go to www.fotos.web.de/robobass
(You don't need to read German, just click on the folder icon at the
bottom left.) I have a Mouser catalog CD, but I'm not getting anywhere
just searching with these numbers.

Are you in Germany? There should be local vendors of such
components.

Does anyone know this logo?

Doesn't really matter.

Also, the transistors say BC 550B. Again, anyone know the brand?

Again, doesn't really matter a BC550B is a BC550B.
This is a European type part number. Should also be a commodity
part available in lots of places.

Note that alt.binaries.schematics.electronic is a good place for
component identification. And you can post your photo directly.

Assuming you tried to get a schematic diagram?
Note that you can always remove the questionable
components and measure them out of circuit.