[baronbeehive]

 pin

Caps are not polarized so no.
Only have to make sure it is at the cathode resistor ground end , not the anode side.

Anyways, you are asking about driver stage decoupling caps ,
when the issue is in your output stage tube area.
I am not concerned with the color coding of your wires.
Or how you did it.
I am sure it's OK.
What I am taking about is using your meter to test for connection problem with output.
A short or error can definitely be your actual problem .
So test those dam rear output connections.

I spoke of the rear output pins,
Because they are easy to get to and test without opening the amp

There is a short or bad connection - between all 3 pins on the right hand side outputs and the first pin on the left hand side outputs looking at the pic going clockwise. Also - there is a short or bad connection between all of the 3 pins on the right hand side outputs.
 
Whereas there is no continuity between all 3 pins on the left hand side outputs which is correct.
 

 
 
Could this be the problem??
 

 

[coinmaster]

How do they come out then?

Pull or wedge them out, they are in sockets.

 

 
Could this be the problem??
 

I've been glazing over this issue since your text seems hard to decipher and I'm too lazy to look at it at the moment. Perhaps u can give more specific information on where and what is shorted.
 
http://www.kirkeo.org/sites/default/files/images/node15/XLRpinout.png
https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTTKuGz5E5tFaujULP9HYCZ_MY_0_3wLLDRKhJiOyQOW_bXYzu3uw

 

[baronbeehive]

  ............
I've been glazing over this issue since your text seems hard to decipher and I'm too lazy to look at it at the moment. Perhaps u can give more specific information on where and what is shorted.
 
...........

 
Sorry coin, while trying to be clear I ended up confusing everybody lol.
 
I got as far as the opamp and was going through other possible things I may have done wrong to cause the problem hence my recent posts.
 
Ignore this next post, I think everything here's fine:
 
Quote:

  This is stock.
 

 
My connections are as stock - blue, brown, blue, brown, black from left to right. The black is only one wire from one of the 2 cable runs isn't it? I cut off the black off the other cable, which means that the right hand output black wire isn't connected to the XLR headphone jack. I'm sure that was how the stock wires were connected as shown in the pic.
 

 
Are the WIMA legs connected correctly? I have joined the 2 legs correctly but does it matter which of the legs connects to which of the 2 sets of resistors?

 
Initially I wanted to test the 6 red output wires in one of the pics below so I tested for continuity from the tube pins to the output XLR's and this is was when I found the problem.
 
This is the problem I found:
 

   
There is a short or bad connection - between all 3 pins on the right hand side outputs and the first pin on the left hand side outputs looking at the pic going clockwise. Also - there is a short or bad connection between all of the 3 pins on the right hand side outputs.
 
Whereas there is no continuity between all 3 pins on the left hand side outputs which is correct.
 

 
 
Could this be the problem??
 

 
As I said here there is continuity between all 3 pins on the right hand XLR outputs. Also there is continuity between all 3 pins on the right hand XLR outputs and one pin on the left hand XLR outputs. Both test results clearly indicate a wiring problem. I don't know what as yet.
 
The next post I flagged up as a possible problem but may be OK. The reason was because both wires of the 2 core grey wire in the middle reverse of board came off and I may have soldered them back wrong, though I don't think so. I don't know what this wire does but the 2 cores indicate the 2 circuits on left and right sides.
 

   
This one in the middle which is brittle and breaks off:
 
You can see the red wire has come off but in the end both came off.
 

 

 

 
The bottom line is there is a wiring issue which may be the cause of the problem.
 
Next I'm going to do a continuity test again on the 4 tube circuits, as you suggested, to look for problems in the bad right hand circuit to check if the problem is somewhere there. I'll let you know when I have the results.

 

[baronbeehive]

These are the results of the continuity test having tested a good left hand circuit, and both right hand circuits where the problem lies:
 
The tests all agree with each other except for the following results:
 
1 - The suspect middle right hand circuit shows continuity between pins 5 and 6
 
2 - The suspect middle right hand circuit shows continuity between pin 3 and the 330 ohm resistor
 
3 - The outside right hand circuit shows continuity over its coupling cap
 
I've double checked this and this appears to be somewhere where the problem must be if anyone has any ideas.
 
This is in addition to the wiring anomalies at the output XLR's identified earlier.

 

[hakiu1980]

very nice tube amp, did someone try ting feng 6 pro ? 

 

[Maxx134]

I was not around yesterday but seems to me like this short wire issue is causing your resistor to burn so bottom line you're wiring maybe crossed.

Test again without the tubes.
Pull out the tubes and see if you still getting continuity.
Remember this is a test with the amp off nothing is on or connected

 

[Maxx134]

Disconnect any input sources to the amp as well and then try

 

[SonicTrance]

   

As I said here there is continuity between all 3 pins on the right hand XLR outputs.

You have shorted outputs!
Pin 1 on the XLR outputs are suppose to connect to ground (on both output jacks) and then be joined together at the 4 pin XLR headphone output ground.
If you have continuity between all pins on the output jack, they're all grounded! Fix that as number one is my suggestion.
 

Also there is continuity between all 3 pins on the right hand XLR outputs and one pin on the left hand XLR outputs. Both test results clearly indicate a wiring problem. I don't know what as yet. 

Probably (hopefully) pin 1, which is suppose to be grounded and have continuity to pin 1 on the other jack.

 

[baronbeehive]

I was not around yesterday but seems to me like this short wire issue is causing your resistor to burn so bottom line you're wiring maybe crossed.

Test again without the tubes.
Pull out the tubes and see if you still getting continuity.
Remember this is a test with the amp off nothing is on or connected

 
 

  You have shorted outputs!
Pin 1 on the XLR outputs are suppose to connect to ground (on both output jacks) and then be joined together at the 4 pin XLR headphone output ground.
If you have continuity between all pins on the output jack, they're all grounded! Fix that as number one is my suggestion.
 
Probably (hopefully) pin 1, which is suppose to be grounded and have continuity to pin 1 on the other jack.

 
Thanks Sonic and Maxx! I will get on with that after I've considered... ie. after I know what I'm doing

.
 
I've spent a fair bit of time today looking at pics of the wiring and I'm 99% convinced that if there is a wiring problem it could only be from crossed wiring with one of the output wires.
 
One last thing, can you tell me if both black wires of the 3 core runs ending in the XLR headphone out are connected. As I said recently only one is connected with mine because I'm sure that was how it was originally. I remember taking the stock wires off and being surprised that one of the black ones was cut off before reaching the socket.

 

[SonicTrance]

 

I was not around yesterday but seems to me like this short wire issue is causing your resistor to burn so bottom line you're wiring maybe crossed.

Test again without the tubes.
Pull out the tubes and see if you still getting continuity.
Remember this is a test with the amp off nothing is on or connected

 
 

  You have shorted outputs!
Pin 1 on the XLR outputs are suppose to connect to ground (on both output jacks) and then be joined together at the 4 pin XLR headphone output ground.
If you have continuity between all pins on the output jack, they're all grounded! Fix that as number one is my suggestion.
 
Probably (hopefully) pin 1, which is suppose to be grounded and have continuity to pin 1 on the other jack.

 
Thanks Sonic and Maxx! I will get on with that after I've considered... ie. after I know what I'm doing

.
 
I've spent a fair bit of time today looking at pics of the wiring and I'm 99% convinced that if there is a wiring problem it could only be from crossed wiring with one of the output wires.
 
One last thing, can you tell me if both black wires of the 3 core runs ending in the XLR headphone out are connected. As I said recently only one is connected with mine because I'm sure that was how it was originally. I remember taking the stock wires off and being surprised that one of the black ones was cut off before reaching the socket.

They're suppose to be connected, joined together at the headphone output. They're not signal but ground wires giving the headphone output jack a ground reference. I doubt that it would make much difference if only one is connected.
I would connect them both though just because.

 

[Maxx134]

I used to look at my wiring in the old days but after my amp started turning more complex & looking like spaghetti, I use my meter as my eyes instead

 

[baronbeehive]

I used to look at my wiring in the old days but after my amp started turning more complex & looking like spaghetti, I use my meter as my eyes instead

 
Good point! No use looking at yours, I'm already cross-eyed from trying to figure out mine

 
 
The problem is made worse by replacing 3 colours of wire with just one lol.

 

[Maxx134]

If there was a problem with the opamp or area of the DC offset servo controlling the balance of the tubes, then the protection relay would have kicked in.

Therefore it is another clue that was not the case, and you did find the culprit of the burning resistor in the output wiring.

You don't have to pull out board to fix or trace wiring.
Just unsolder wires from board at the XLR plugs.

On the board (component side) , you will see the markings on the negative tube pins.
The will say "left-" and on other side "right-" .. for the negative side of signal.

On the middle of board you will see the positive signal markings left & right "+" positives..

The remaining wires are "ground".
So you use your tester to touch each point labled on board and then check the wires one at a time to identify which is which.

If all seems correctly positioned, then look to the wiring at the headphone socket.

Most probably it was a simple mistake of the male & female plugs having to be oppositely wired and just a mixup.
Edit*
At least we hope that's all that's wrong for now..

 

[baronbeehive]

  These are the results of the continuity test having tested a good left hand circuit, and both right hand circuits where the problem lies:
 
The tests all agree with each other except for the following results:
 
1 - The suspect middle right hand circuit shows continuity between pins 5 and 6
 
2 - The suspect middle right hand circuit shows continuity between pin 3 and the 330 ohm resistor
 
3 - The outside right hand circuit shows continuity over its coupling cap
 
I've double checked this and this appears to be somewhere where the problem must be if anyone has any ideas.
 
This is in addition to the wiring anomalies at the output XLR's identified earlier.

 
I've just checked the circuits again with tubes out and everything is as before with tubes in, but there are a couple of addtional points to add to the above which I missed yesterday:
 
4 - The suspect middle right hand circuit shows continuity between pins 3 and 6
 
5 - the suspect middle right hand circuit shows continuity between pins 2 and 6
 
6 - the suspect middle right hand circuit shows continuity between pin 5 and cathode bypass/330 ohm cathode resistor
 
7 - the suspect middle right hand circuit shows continuity between pin 3 and cathode bypass/330 ohm cathode resistor
 
8 - the suspect middle right hand circuit shows continuity between pin 5 and 330 ohm anode resistor
 
9 - the suspect middle right hand circuit shows continuity between pin 6 and 330 ohm anode resistor
 
If anyone can see a pattern in this let me know!
 
Now I'm going to test the wires.
 
Edit: I've just seen a pattern, the problems are in both plates and cathodes, apparently not the grid.
 
Edit 2: Just tested the output XLR's from the positive and negative points on the board. All good except the right hand negative. I've revised my results yesterday so they are as follows now:
 
1 - There was continuity with pin 1 of right hand XLR output from right hand -ive on the board.
2 - There was continuity with pin 2 of right hand XLR output from right hand -ive on the board.
3 - There was continuity with pin 1 of left hand XLR output from right hand -ive on the board.
4 - There was continuity with pins 1 and 2 of right hand XLR output testing just the XLR's (not from the board).
 
This post summarizes the test results to date, I've spent most of the day on this.
 
What makes me think it's the output wiring is because I've checked the 4 runs of 3 core wires and they are connected correctly, (except for the lack of an earth wire in one of them as I mentioned earlier which was the same as stock wiring). That leaves the 6 output wires............. HOWEVER the left and right hand +ives are correct and the left hand -ive is correct and the left hand ground is correct and therefore the continuity with the right hand pin probably indicates ground on the right hand pin therefore the other right hand pin is probably correct .......... so the output wires are probably correct? (Or these 2 pins could be reversed).
 
I believe the connections are all correct so if I can find out where the short is that could be the answer because it is all the power in the right -ive connection that is draining out and could explain why there is practically no voltage going through the middle right grid pin 1.
 
You can compare the above anomalies with the good circuit:
 
1 - pin 3 has continuity with pin 5
2 - pin 7 has continuity with pin 8
3 - pin 2 has continuity with 330 ohm anode resistor, WCF and cathode bypass/cathode 330 ohm resistor
4 - pin 6 has continuity with cathode bypass/cathode 330 ohm resistor
5 - cathode bypass/330 ohm cathode resistor has continuity with cathode bypass/330 ohm cathode resistor and 330 ohm anode resistor
6 - WCF has continuity with 330 ohm anode resistor
 
I don't know what to do next to try to find the short if it is that.

 

[baronbeehive]

Quote:

Originally Posted by baronbeehive /img/forum/go_quote.gif
..................
 
What makes me think it's the output wiring is because I've checked the 4 runs of 3 core wires and they are connected correctly, (except for the lack of an earth wire in one of them as I mentioned earlier which was the same as stock wiring). That leaves the 6 output wires............. HOWEVER the left and right hand +ives are correct and the left hand -ive is correct and the left hand ground is correct and therefore the continuity with the right hand pin probably indicates ground on the right hand pin therefore the other right hand pin is probably correct .......... so the output wires are probably correct? (Or these 2 pins could be reversed).
.......

 
 Sorry if that sounded garbled, I've just corrected some faulty reasoning.
 
Quote:

  .................
 
I believe the connections are all correct so if I can find out where the short is that could be the answer because it is all the power in the right -ive connection that is draining out and could explain why there is practically no voltage going through the middle right grid pin 1.
..........

 
Therefore the short is somewhere between pins 1 and 2 from the right hand -ive connection on the board.