hi Dan：
I have something wrong with my vht .
A few days ago, one of the b channel of the rear tube kt88 of vht was broken, and then the fuse of the b channel was also broken. There was an electric current sound on the same day. I thought the tube was broken, so I bought two pairs of k88 tubes and replaced them today. The guitar sound is ok, but there is an extra electric current sound.
I took a video and asked you to help me judge what might be wrong.
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Shane,
Look at the lower center area of the power tube board where the red and black wires connect to the board.
There are two vertically oriented 100 ohm resistors there.
Do they look burned? If so, that would have been caused by a shorted power tubes and they would need to be replaced.
Dave
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MODEL G-2902-S/II
thank u very much
I found a possible problem according to the tips on the forum. Now I want to know the resistance value and wattage of the resistors of r201 and r202. I need to buy one and replace it.
Attached is the position of the burned resistor.
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I want to know what could be the reason why these two resistors burned out? How can I avoid it later?
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Thank you for your help. There are a few other questions that I look forward to your reply.
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MODEL G-2902-S/II
thank u very much
I found a possible problem according to the tips on the forum. Now I want to know the resistance value and wattage of the resistors of r201 and r202. I need to buy one and replace it.
Attached is the position of the burned resistor
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Shane,
Those are 100 ohm 2W resistors.
You probably had a shorted power tube, so you would need to replace the tubes in whichever channel blew the front panel channel fuse. If you provide a photo of the tube area, we’ll be able to advise about which replacements to get.
Dave
I changed the two 100 ohm 2 watt resistors you mentioned today. I measured that these two resistors are connected in parallel, right? After I changed resistor and energized it, their resistance value was 50 ohms, and I have also replaced the fuse. Is there anything else that needs to be checked?
Those resistors are not in parallel, but they would more or less measure that way in circuit, so you should be good to go now.
The amp is an older model and doesn’t have the stock tubes. Those look like Psvane, by the way. Just about anything would be fine these days.
I suggest you try the Sovtek 6550s. They are readily available and generally reliable.
Dave