Hi all!
I have just finished the assembly of my 8200R, I only get a big hum through the speakers even a low volume and no music. I have checked and I don’t see any big mistake. DC voltages are in range although left channel voltages are about 10% higher than right one. I would really appreciate if someone could help me with a similar problem or some hint for troubleshooting. Thank you in advance
I have just finished the assembly of my 8200R, I only get a big hum through the speakers even a low volume and no music. I have checked and I don’t see any big mistake. DC voltages are in range although left channel voltages are about 10% higher than right one. I would really appreciate if someone could help me with a similar problem or some hint for troubleshooting. Thank you in advance
I have checked and I don’t see any big mistake.- I can walk you thru to locate the issue..Pls send your phone number to my email info@vkmusic.ca
I hate to say this - I have the same problem. I've built several guitar amps over the years and the Elekit TU8200R is the easiest build I've ever done. But maybe I got complacent. I've reflowed all the solder connections although they all lokked perfect to start with. I recehecked the values and placement of all components. It has a loud hum regardless of volume setting, the hum reduces volume when I touch the volume knob or switches. No signal from the input at the output. Tomorrow I'll try to follow the path with an oscilloscope.
Did you solder unit#4 and 5 together?
How about unit #5 and 6?
Please check the manual page 6 unit#6 step 2
Page 7 unit4 step 3
Hope you will find the magic
How about unit #5 and 6?
Please check the manual page 6 unit#6 step 2
Page 7 unit4 step 3
Hope you will find the magic
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Yes, I made the solder bridges, but that's the area I suspect now. I found that if I ground the outer shield of any input jack to the main board the hum is eliminated, but I still have no sound.
I suggest you to check your soldering and all the connections between PCBs.
If you do not insert the CN1 and CN2 propery, you will not have sound.
Did you solder CN1 and CN2?
These are common errors .....
Please read the manual step by step one more time.
If you send me all the test points, I can hrlp you located the issue..
If you do not insert the CN1 and CN2 propery, you will not have sound.
Did you solder CN1 and CN2?
These are common errors .....
Please read the manual step by step one more time.
If you send me all the test points, I can hrlp you located the issue..
Hi Victor, I appreciate your help. I took everything back apart, reflowed the unit connections, then tried it again. Here's what I found - with nothing connected to the input jacks, it's silent. My voltages were all good until I got to #29. I'm reading -30.6 volts at that point - the chart shows 6.0-6.8. Here are all of the voltage readings:
1,2 - 3.4V
3,4 - 3.4-3.5V
5,6 - 105-106V
7,8 - 105-106V
9,10 - 19.8V
11,12 - 1.1V
13,14 - -15.2V
15,16 - 267V
17,18 - 0.45V
19,20 - 259V
21,22 - 264V
25 - 279V
26 - -30.7V
27 - -32.1V
28 - 5.8V
29 - -30.6V
What did I miss? How do I have negative voltage at 29? I'll take off the main board and look at D7 again.
Thanks again,
Mike
1,2 - 3.4V
3,4 - 3.4-3.5V
5,6 - 105-106V
7,8 - 105-106V
9,10 - 19.8V
11,12 - 1.1V
13,14 - -15.2V
15,16 - 267V
17,18 - 0.45V
19,20 - 259V
21,22 - 264V
25 - 279V
26 - -30.7V
27 - -32.1V
28 - 5.8V
29 - -30.6V
What did I miss? How do I have negative voltage at 29? I'll take off the main board and look at D7 again.
Thanks again,
Mike
Please check page 8 of the floor plan of the PCB. You need to cross refer to the floow plan
For PT29... Did you install the diode in the wong polarity..
For PT29... Did you install the diode in the wong polarity..
My manual is a poor copy and page 8 is difficult to read. What is PT29? All Diode, Zeners and D5,D6, D7 are oriented correctly.
Problem solved! Apparently I had a solder bridge - no thicker than a wisp of spyder web - on D7. Copper solder wick took care of that. Amp is silent now until I feed a signal, then it sounds marvelous! Thanks for taking the time to look at my issue.
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Hi all!
I’ve had an Elekit TU-8200R for about three years and it’s run beautifully.
Recently a crackle started in one channel that wasn’t addressed by swapping out the speaker, cables, or tubes.
On voltage testing I’ve found that test point 2 = 1.6V (3.2-3.7) and point 6 = 52V (100-120V) Everything else tests normally.
I don’t have the electronics knowledge to know what to do with this.
Any help would be really appreciated!
I’ve had an Elekit TU-8200R for about three years and it’s run beautifully.
Recently a crackle started in one channel that wasn’t addressed by swapping out the speaker, cables, or tubes.
On voltage testing I’ve found that test point 2 = 1.6V (3.2-3.7) and point 6 = 52V (100-120V) Everything else tests normally.
I don’t have the electronics knowledge to know what to do with this.
Any help would be really appreciated!
Attachments
when you have the new tubes please send me the new tests points
if you have uncontrolable low level hum it is the FET issue.
if you have uncontrolable low level hum it is the FET issue.
Thanks again for your help. The tubes don’t change the test voltage levels. What do you think I should try next?