99% of the time, problems when building the amp come from soldering issues and installing components in the wrong polarity.
The following is a common example. The amp was fixed by Mr. Fujita just today.
Here is my suggestion. Please follow the manual step BY step.
When you finish the main PCB. Please cross reference to the floor plan from the manual
C116 and Q102 are installed incorrectly.
In addition, some soldering points are not covered by solder.
Correct polarity....
ReD: after repair
Pencil : before repair
The following is a common example. The amp was fixed by Mr. Fujita just today.
Here is my suggestion. Please follow the manual step BY step.
When you finish the main PCB. Please cross reference to the floor plan from the manual
C116 and Q102 are installed incorrectly.
In addition, some soldering points are not covered by solder.
Correct polarity....
ReD: after repair
Pencil : before repair
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Victor,
I've got an issue with a Tube Depot purchased TU-8600S. After a number of hours of use the Left channel drops off. The only voltage issue I see is at TP-27, which is low at ~14.5VDC, instead of being at 16-22. Once the unite cools for a minute then returns. Again, difficult to ascertain because with the covers off it seems fine but to simulate the overheat condition you have to have the covers on and when you pull them off it cools quickly and the channel returns.
From power up, TP-27 just slowly drops.
The problem could be Q101, NDF02N60Z (which is of course is obsolete).
I realize you didn't sell this kit but if you have any ideas I would appreciate it.
Regards,
Greg
I've got an issue with a Tube Depot purchased TU-8600S. After a number of hours of use the Left channel drops off. The only voltage issue I see is at TP-27, which is low at ~14.5VDC, instead of being at 16-22. Once the unite cools for a minute then returns. Again, difficult to ascertain because with the covers off it seems fine but to simulate the overheat condition you have to have the covers on and when you pull them off it cools quickly and the channel returns.
From power up, TP-27 just slowly drops.
The problem could be Q101, NDF02N60Z (which is of course is obsolete).
I realize you didn't sell this kit but if you have any ideas I would appreciate it.
Regards,
Greg
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TU-8600S is a very stable amp. it is very rare has issue with the FET filter. 99% is the soldering issue
Tube dept is ordered from me. I have no problem to assist you.
I suggest ypu chech all ypur soldering points.
Tube dept is ordered from me. I have no problem to assist you.
I suggest ypu chech all ypur soldering points.
Victor,
Thank you for helping.
I have reflowed everything and the V-drop occurs as the board and Q101 heat. Starts at 15V and continues to drop until the channel drops off. Runs for several hours but as the case heats up it eventually fails.
This was actually purchased from you but the builder is in California and I’m fixing it for the buyer in another state.
Thank you for helping.
I have reflowed everything and the V-drop occurs as the board and Q101 heat. Starts at 15V and continues to drop until the channel drops off. Runs for several hours but as the case heats up it eventually fails.
This was actually purchased from you but the builder is in California and I’m fixing it for the buyer in another state.
Victor,
That’s a great offer. Do you have any NDF02N60 FETS in stock and maybe I could pay for the shipping and you send me a couple?
That’s a great offer. Do you have any NDF02N60 FETS in stock and maybe I could pay for the shipping and you send me a couple?
Victor,
FETs arrived today (that was Very fast). New FET is in and the V is holding at just ~16VDC, which is at the bottom of the range. Amp is heating and I will let you know. Probably going to be fine.
Thank you very much.
Greg
FETs arrived today (that was Very fast). New FET is in and the V is holding at just ~16VDC, which is at the bottom of the range. Amp is heating and I will let you know. Probably going to be fine.
Thank you very much.
Greg