That's impressive details and very helpful idea. Unfortunately, my mk8se still cant find out the error yet even after change NPN & PNP transistor, Zener diode and resistors, the amp still read '0' after right side VU Meter light up while turning onThanks!
Its kinda baffling how some of the wiring is just routed so poorly.
On another note, one of my 100Ohm 5W resistors went up in smoke... any idea what could cause this ? I turned off the amp instantly and have ordered 10W Mills resistors instead. But im rather curious what could be the reason, everything else looks perfectly normal.
EDIT - Well found my idiotic mistake that cause one of the filter caps to go bye bye -
In case anyone new is wondering, that circled wire need to goto the ground pad to the left.
Sad i have to wait 2 more days now, everything was looking so pretty -
The problem is I don't know how to check the voltage, need guidance
While turn on the amp, I heard sound 'pop' like short explosion after second VU meter light up. However when I open the case, fuse show normal. can't find any circuit, resistor and wire burn even after check with DMM,So as its been stated before BE VERY VERY CAREFUL BEFORE MEASURING VOLTAGE ON A LIVE / ACTIVE AMPLIFIER or any electrical equipment!!!!
Make sure the tubes installed are good, and the amps is upside down propped up on something stable! You do not want, it moving around or sliding/falling when turned on. Before plugging in the mains cable, double check everything and the surrounding area has plenty of space, and nothing interferes when you are moving around or moving the multi-meter leads around.
Next, switch the Multi-meter to DC Voltage mode and put the Black / Negative lead from your multi-meter into one of the holes circled BLACK , this way you can freely move around your other hand.
You want to first measure your voltage to the terminals circled red. If all of these are consistent, then your PSU stage is fine. On the MK VI+ , they are @ 100V for me. @Maxx134 or @SonicTrance might know what they should be for the MK VIII.
Next if those are fine and the PSU stage is indeed OK , then you should measure the voltages, at the terminals circled white. Im not sure how much they should be on the MK VIII , as that amp uses different tubes. So someone else like @Maxx134 will have to chime in. and tell you if the values that you report are in line or not and that will help in tracking down the issue.
After if the voltages at the terminals marked red and white are consistent, and seem normal. Check at the terminals marked yellow.
Once you take the readings, post them here. And make sure you mentioned what value is from which point to which point.
AGAIN>>> BE VERY VERY VERY CAREFUL!!!! IF YOU FEEL THIS IS A LITTLE TOO DANGEROUS OR DO NOT KNOW WHAT TO DO/HOW TO DO.... STOP! And Maybe find someone else around you who knows their way around electronics to do it for you.
A shock from a live equiment like this can kill you, SO BE CAREFUL!!
what's the value? thanksThat's good advice from bloodhawk, just remember not to touch anything while the amp is switched on, except with your multimeter, also leave it to discharge after you switch it off for about 30 minutes before touching anything.
I am wondering if your headphone protection circuit kicked in. If so there must be something causing that to happen.
Have you taken values of every resistor in the orange circle below, I can give you the proper values if you want.
That's a bit different resistors value between mk6 and mk8, I had checked all those resistors and nothing wrong.....might be easier to read....
Edit: I'm pretty sure they're the same on the MKViii.
I assembly back to simple setup and just got all the voltage reading now, seem like something error on right side output.So as its been stated before BE VERY VERY CAREFUL BEFORE MEASURING VOLTAGE ON A LIVE / ACTIVE AMPLIFIER or any electrical equipment!!!!
Make sure the tubes installed are good, and the amps is upside down propped up on something stable! You do not want, it moving around or sliding/falling when turned on. Before plugging in the mains cable, double check everything and the surrounding area has plenty of space, and nothing interferes when you are moving around or moving the multi-meter leads around.
Next, switch the Multi-meter to DC Voltage mode and put the Black / Negative lead from your multi-meter into one of the holes circled BLACK , this way you can freely move around your other hand.
You want to first measure your voltage to the terminals circled red. If all of these are consistent, then your PSU stage is fine. On the MK VI+ , they are @ 100V for me. @Maxx134 or @SonicTrance might know what they should be for the MK VIII.
Next if those are fine and the PSU stage is indeed OK , then you should measure the voltages, at the terminals circled white. Im not sure how much they should be on the MK VIII , as that amp uses different tubes. So someone else like @Maxx134 will have to chime in. and tell you if the values that you report are in line or not and that will help in tracking down the issue.
After if the voltages at the terminals marked red and white are consistent, and seem normal. Check at the terminals marked yellow.
Once you take the readings, post them here. And make sure you mentioned what value is from which point to which point.
AGAIN>>> BE VERY VERY VERY CAREFUL!!!! IF YOU FEEL THIS IS A LITTLE TOO DANGEROUS OR DO NOT KNOW WHAT TO DO/HOW TO DO.... STOP! And Maybe find someone else around you who knows their way around electronics to do it for you.
A shock from a live equiment like this can kill you, SO BE CAREFUL!!
