My DC-5 has a really bad hum. the power (wattage) seems ok. Still powerful. But regardless it has a really loud hum. Here's what I've checked/done so far ...
Changed every electrolytic cap with new original mesa caps. Just for maintenance and hoping it was a filter cap issue
Changed power and pre-amp tubes.
Checked all voltages , Plate and screen V's seem ok.
Not sure how to check the Power transformer. Each pin on the transformer gives me zero voltage with one side to ground. Also the 220ohm 5W resistor (which i cant seem to trace on the schem) is getting super hot (maybe thats normal)
Here is a pic of the amp http://i64.photobucket.com/albums/h171/mypicspics/DC-5.jpg
B+ voltage = 440V (OK) ; Checked V1a to V6b voltages ....
On V4a I get 222v. that's high. According to the schem it should be 188v. Not sure if this is my culprit.
Just wondering if you guys can help lead me in the right direction. thanks
Here is a link to youtube that shows my amp's noises ...
http://www.youtube.com/watch?v=cgewTdGr1m8
I am just starting to learn about amps and electronics so any help would be extremely appreciated
Changed every electrolytic cap with new original mesa caps. Just for maintenance and hoping it was a filter cap issue
Changed power and pre-amp tubes.
Checked all voltages , Plate and screen V's seem ok.
Not sure how to check the Power transformer. Each pin on the transformer gives me zero voltage with one side to ground. Also the 220ohm 5W resistor (which i cant seem to trace on the schem) is getting super hot (maybe thats normal)
Here is a pic of the amp http://i64.photobucket.com/albums/h171/mypicspics/DC-5.jpg
B+ voltage = 440V (OK) ; Checked V1a to V6b voltages ....
On V4a I get 222v. that's high. According to the schem it should be 188v. Not sure if this is my culprit.
Just wondering if you guys can help lead me in the right direction. thanks
Here is a link to youtube that shows my amp's noises ...
http://www.youtube.com/watch?v=cgewTdGr1m8
I am just starting to learn about amps and electronics so any help would be extremely appreciated