Anyone elses DC-5's hum when cranked? (non tube issue)
- Thread starter dogboy131
- Start date
Help Support The Boogie Board:
MJ Slaughter
Well-known member
That is a real pisser. I would have thought the tech would have tested the amp before letting you pick it up. I changed my caps, just remember to discharge them before fiddling around. The most difficult part of the process for me was removing the glue on the old caps so I could pull them off. For me, slicing the blue covering with a razor, clipping midway on the leads, removing the cap, remove left over leads on the PCB the carefully trimming the blue covering off the PCB worked well for me. Just be careful not to damage any traces on the board.
yup i replaced all the caps last night and the amp sounds perfect. im not sure what was really at fault, because i did replace the main, secondary filter caps, along with the caps in the fixes bias circuit, as well as a couple other small ones. but some total the amp is now a lot more quiet, and no more microphonics on the lead channel!
i am pretty disapointed in the tech. Albeit the LDR's do go back from time to time and it was prob best to change them, it was something i could have done very quickly. The reason i took my amp to him and pay him was because i wass all out of ideas and i wanted him to trouble shoot. Needless to say, if you ever need your Boogie serviced in the state of MD, message me and ill tell you which one to avoid.
What pisses me off the most is how confident he was that he fixed the problem. *******
i am pretty disapointed in the tech. Albeit the LDR's do go back from time to time and it was prob best to change them, it was something i could have done very quickly. The reason i took my amp to him and pay him was because i wass all out of ideas and i wanted him to trouble shoot. Needless to say, if you ever need your Boogie serviced in the state of MD, message me and ill tell you which one to avoid.
What pisses me off the most is how confident he was that he fixed the problem. *******
Hi,i'm new on the mesa board.I was reading about your progress with this problem.I'm having the same problem with my dc-5.And I hoped it would end up to be tube thing.I dont know anything about caps and replacing them.What do caps do in the amp?
Thanks!
Thanks!
francesthemute
Member
- Joined
- Jan 29, 2009
- Messages
- 7
- Reaction score
- 0
My DC-2 does that when I turn the reverb past a certain point.
i posted a new thread for the problem, but it looks like i have a fix. I bypassed the section of the amp that contains the graphic EQ. The eq board itself was not the problem, but it looks like it was one of the transistors ( there are 4). If you want to try to see if this might be your problem as well ( i really have gone through everything else at this point).
The main thing, patching my guitar into the FX return, there was no hum, so i know the power amp section was intact, and the problem was isolated to the preamp. Coming from both master volumes for each channel, they lead into an Orange Drop cap that is rated at .01. This cap is right behind the second to left EQ slider ( this is on the main board, but the orientation, looking from the front and top of the amp) The cap is also just to the side of the 4 transistors. If you clip the inner leg of this capacitor,you can bypass the entire section. I have foot long cables with aligator clips on each end that make this easy work.
With the inner leg of the cap clipped, i connected to open end of the cap to the left prong on the FX wet pot. Turned the amp on. The volume was considerably lower, and i am not sure why, but there was no hum on either channel. I then decided to remove the aligator clip from the free cap leg. and attach it to the front leg that was still attached to the board. The hum was still gone, and the volume had returned a bit more, enough to make me confident enough to order new transistors from mouser ( they are like 80 cents a piece..if this is the answer i will die at the 250 i have already spent tracking this down.
After this i disconnected my test wires and reconnected the open cap. The amp was back to full volume and the hum was back. I will post what happens after i install the transistors...if that doesnt work...im either going to sell the amp, or only use it for the power amp...which i have to say sounds pretty good behind a couple of my pedals.
The main thing, patching my guitar into the FX return, there was no hum, so i know the power amp section was intact, and the problem was isolated to the preamp. Coming from both master volumes for each channel, they lead into an Orange Drop cap that is rated at .01. This cap is right behind the second to left EQ slider ( this is on the main board, but the orientation, looking from the front and top of the amp) The cap is also just to the side of the 4 transistors. If you clip the inner leg of this capacitor,you can bypass the entire section. I have foot long cables with aligator clips on each end that make this easy work.
With the inner leg of the cap clipped, i connected to open end of the cap to the left prong on the FX wet pot. Turned the amp on. The volume was considerably lower, and i am not sure why, but there was no hum on either channel. I then decided to remove the aligator clip from the free cap leg. and attach it to the front leg that was still attached to the board. The hum was still gone, and the volume had returned a bit more, enough to make me confident enough to order new transistors from mouser ( they are like 80 cents a piece..if this is the answer i will die at the 250 i have already spent tracking this down.
After this i disconnected my test wires and reconnected the open cap. The amp was back to full volume and the hum was back. I will post what happens after i install the transistors...if that doesnt work...im either going to sell the amp, or only use it for the power amp...which i have to say sounds pretty good behind a couple of my pedals.
dwsabianguy
Well-known member
I don't get any noise out of mine, besides some feedback when cranked.
So the amp is in the back of my car, heading to the amp tech at 3 today. I am really hoping for some good news here. Im really willing to pay anyhting at this point to get the hum out...
...makes me miss my Son Of the Boogie head....never had one problem with that thing!
...makes me miss my Son Of the Boogie head....never had one problem with that thing!
MJ Slaughter
Well-known member
How long before you get your amp back?
So i dropped the amp off...the tech shop looked pretty loaded with tube amps, but they do a lot of other work on PA stuff. The kid at the counter told me that the lead time is two weeks, but that the tube amp tech would prob get back to me in about 7-10 days...the wait is killing me, but so wass the hum!
Similar threads
