Can you suggest what component goes in the output circuitry?

[Peter Born]

I am building a Chinese valve amp which arrived with the wrong schematic. The motherboard labels were clear, except for the output circuit. Can anyone suggest what goes in the tiny slots labeled 470(?) and 1000(?) in the attached photo?

Thanks in advance,

Peter

 

[Enzo]

If I had to guess, I'd say a 100 ohm resistor and a 470pf cap.


Trace out the circuit there and draw up at least a partial schematic from the board.

 

[S4m]

I think it's 470pF and 1000nF-> 1µF polypropylene Caps like WIMAs...

 

[Refugee1]

They look like they are connected in parallel with two resistors that are in series with the output.
There should be two low capacitors left over that if added will give a slight treble boost if they are fitted.
It will not be a big problem if they are left out.
You could experiment with them without doing any harm.

 

[godfrey]

They look like they are connected in parallel with two resistors that are in series with the output.

Agreed. So by symmetry the two parts should be the same, otherwise left and right channels will be different.

Seems like an odd idea to have 36K resistors in series with the outputs in the first place.😕

 

[Peter Born]

Many thanks to those who responded. It's a pleasure to join a helpful and civil group.

I'll try leaving the slots empty first and see if the amp works. I agree they should be the same by symmetry and that a missing capacitor here at the output would not be dangerous.

Unluckily, parts were missing from the kit, so I cannot use the left over components to figure this out. In some ways, this build is more interesting than the fully equipped, fully explained kits I've built in the past--there's more to figure out.