Ground Wire (grey)

Hello!
I ordered a MadAmp A15MkII Delux..
Got the package and read the manual. In the beginning, therre is a grey ground wire that has to be connected. I see this wire has kopper and one silver leader inside.. How to connect them? Figure doesnt show that well.

And in the transformator, I see there are some really thick green cables..
I dont have those. The only thick i have, is the grey one. And one with yellow/green. But this one is only 4cm long!
Im talking about the picture where it says:

Zitat

This connection is your life insurance, when, by some circumstances, high voltage isapplied to your chassis!

thanks.. Really lookin forward to start with the project. Allready bought a V30 element to make a combo!

Cheers from western Norway!

Thanks for the answer. This makes it easier

2. Oh, i see what you mean.. I kinda refered to the green thick cable in the picture of the transformator.. Its a thick green wire between pin 13 and 15, double.
I just want to be 100% sure: I guess i have to use the grey cable there, because they are the same?

Again, thanks for the fast answers. Just wanna be 100% sure before starting with it, as there are high voltages involved..

I see..!

So, today I started with my kit. Did the poweramp finish.
Started with the preamp.. I connected the inner in grey wire as told in the manual. The shielded wire in grey I only connected to the ground in one side.
But should i NOT connect it to anything in the other way? Why so?

And I noticed..
C2,C14,C16 - 1uF/100V MKT
I couldnt find those any place.. i searched in the whole box and tried to measure the capasitans in every capacitor.. Still, they are not in the package.

Hi again! I fould out, and everything seems to be in place.
I have one problem though.. I was finished wiring the power switch, primary side of the power transformer and main fuse.

I was going to measure the voltage as listed in manual:

Zitat

a) Primary
Pins 3-7 230V

b) Secondary
Pins 10-12 265V
Pins 13-15 24V
Pins 16-18 7,4V

I tried to measure pin 3 to ground and then pin 7 to ground.
It gave 84V at pin 3 and then almost nothing at pin 7..
Everything seems to be soldered properly.

Is it right tha I should measure voltage like this:
pin3 and ground
pin7 and ground

Or should i measure FROM pin 3 to 7 with my multimeter?
(AC, right?)

Im very careful because the manual says "Measure all voltages with the ground in chasis as a referance"

thanks

Hi Martin,
again: Thank you for really fast and effective reply.
Im greatfull for the good and helpfull service.

Hi again Martin.
Ive done some more soldering, and i tried to be 100% presice.
I've come to the point where I solderen all heater wires (red/white) and a little bit more.
I was going to measure some voltages, and i dont get it right..

Zitat

a) At the rectifier (+) 355V
b) Output of the power-supply board => C26 (+) 355V
c) Output if the bias control (pin 2/3) -21V to -27V (variable resistor)
d) Heater voltage (red against white wire) 7,4V

c) and d) is okey! I get those voltages when i measure. I also measured all tube sockets, and the heat voltage is ok: 7.4V.

BUT.. I have problems with a) and b)
a) I measure from the (+) at rectifier to the grounding star point, it shows me under 1V..
b) I measure from C26 (+) to grounding star point, this also gives me very, very low voltage.
I dont know whats wrong, really.. Power transformer has ok voltages, i check them before.

Measuring with the fuses inside and only red power switch on, no tubes.

Please help!

Im studying to electronic ingeneer, but not yet used to that big circuits.
I tried mesuring with the Standby on, still get only a couple of mV from the C26 + pin and voltage rectifier.

Im mesuring against the "star ground point" if that helps..

Hi again.
Thanks for the reaally fast reply. I checked the connections of C26, 28, 29 and - at the rectifier, and it has conenction.

BUT.. Then i tried to ohm the F1 and F2. F1 has connection, but F2 NOT!
I opened the fuse, and it looks burned (got some brown burning marks)

Does that tell you anything?
I can actually remember that I heared a little sparkle sound when i switchen the Standby on first time, might be the fuse that broke.

I think the battery at my DMM is ok, since it showes good heater voltage.

Should I try to replace the F2, or is there something wrong since the fuse burns out..?

thanks

I have measured a lot of voltages before, but not that high as here. Thats why im trying to be careful as possible.
I put a new fuse today and tried to measure again. Nothing improved, just a little bit higher voltage at the points, but far, far away from 355V.. And i can hear some sparkling sounds from the poweramp section, maybe the switches or the fuse.. and opened the fuse, it looks a little burned. I tried to see if there were any bad connections, but all connections seems to be soldered solid.

I'll try to desolder the resistors and see what happens later. Need to buy more fuses too, obviously..

Ill also try to go through the whole circuit and see that everything is 100% when i Get time.
Thanks for the help, again.

Hi again!
I got a friend to look at the circuit, and he said that the rectifier is broken, for some reasons..

I thought I'd try to build a new rectifier with 4x n4007 diodes which can handle 1000V each.
Does that sound like a ok idea, or should I buy a new w06 rectifier?

And do you think that there might be an error in the circuit that might cause the rectifier broken, or maybe i was unlucky?

thanks

Just an update:
- I removed the rectifier and made a new one with 4x n4007 diodes, and it WORKS!! I dont know why the old rectifier was broken, but now i measure all voltages OK +/- 5%.
And the new fuse is not breaking, so thats great news..Now i can go on with next part