what are these components?

[JC@]

At first I thought they were a couple of fried resistors but having a close look I realized they must be something else.

[cbarrow7625]

Are they zero ohm resistors (i.e., jumpers)?

[teemuk]

A zero-ohm resistor would have a single black band but this looks like three-bands and a band for tolerance. Inductors?

[cbarrow7625]

Good call. Do you think those caps & the 'other devices' are part of a snubber around the diodes? Could those just be low value resistors in series with those caps as part of the snubber? 2 Ohms?

[JC@]

Good call. Do you think those caps & the 'other devices' are part of a snubber around the diodes? Could those just be low value resistors in series with those caps as part of the snubber? 2 Ohms?

In circuit they measure about 0.4 ohms. The amp is working properly, it came in just for retubing. It would be easy to know what they are with the help of a schem but I don't have it.

[cbarrow7625]

Down in that range most ohmmeters are too accurate. How about yours? What does the meter show with the leads just shorted together? Mine often shows something like 0.4 ohms.

What amp is it?

[52 Bill]

In circuit they measure about 0.4 ohms. The amp is working properly, it came in just for retubing. It would be easy to know what they are with the help of a schem but I don't have it.

They just look like 10R 10% resistors to me (brn-blk-blk-silver). How are they wired in circuit? What kind of amp is this?

[cbarrow7625]

That's brown? Thanks for helping us color blind folk out.

[JC@]

They just look like 10R 10% resistors to me (brn-blk-blk-silver). How are they wired in circuit? What kind of amp is this?

More than probably that's what they are, 52 Bill, I'm very sorry
The amp is an Engl Sovereign 100
I don't know why the rest of the resistors are the usual package and 5% tolerance except these fat vitreous looking ones. Maybe they are some kind of special resistors

[Alex/Tubewonder]

They're in a snubber so they need to be high voltage pulse types (750-1000V).