I have my DC3 combo up for sale as I'm moving to a head/cabinet configuration. Wouldn't you know it, a guy comes over to buy the amp, we turn it on and there are hisses, crackles and pops coming out at lower volumes that gets worse as the volume goes up on both channels. He immediately passed on the amp, of course. I immediately had to take it off the market.
DC-3 Noise - Timing is Everything
- Thread starter jimsz
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GD_NC
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Sorry about that! Crap seems to always happen at the worst moment. 
I wouldn't get too upset about it. If you have a local M/B shop (or any other good amp shop) you can take it in for a tune up & cleaning. More than likely they can find the problem and fix it easily.
Once the amp has been checked out, it's probably worth more since you have a receipt to prove it's been serviced and in good working order. That's something I always ask before I purchase a used amp.
I wouldn't get too upset about it. If you have a local M/B shop (or any other good amp shop) you can take it in for a tune up & cleaning. More than likely they can find the problem and fix it easily.
Once the amp has been checked out, it's probably worth more since you have a receipt to prove it's been serviced and in good working order. That's something I always ask before I purchase a used amp.
Thanks GD, that's most likely what I'll do. I suppose it could have been worse if the guy bought the amp, brought it home and it started doing that, I'd probably have a major hassle on my hands. I'll check out the tubes first and make sure it's not that.
Some details:
The 500K and the 180K cap connected to the V1 tube socket are very loud when tapped ONLY when the amp is on the Rhythm channel and are normal when changed to the Lead channel. There is also a 250k cap attached to the lead of the Rhythm Gain pot that makes a lot of noise when tapped.
There is a 100K cap connected to the V5 tube socket that is loud on both the Rhythm and Lead channels.
Do these caps need replacing or is there some deeper problem?
The 500K and the 180K cap connected to the V1 tube socket are very loud when tapped ONLY when the amp is on the Rhythm channel and are normal when changed to the Lead channel. There is also a 250k cap attached to the lead of the Rhythm Gain pot that makes a lot of noise when tapped.
There is a 100K cap connected to the V5 tube socket that is loud on both the Rhythm and Lead channels.
Do these caps need replacing or is there some deeper problem?
If tapping on them causes hum or crackling noises, or causes the signal to cut in and out, then you have a broken component or bad solder connection.
If tapping on them makes a tapping noise come out of the speaker, this is fairly normal. My DC-10 does this and it works flawlessly.
Also, if the tubes have been changed many, many times, occasionally I've seen the tube socket solder connections get weak. This has been mainly from me swapping tubes in and out constantly so that I can tell my customers what tubes work best with what amps.
Hope this helps.
If tapping on them makes a tapping noise come out of the speaker, this is fairly normal. My DC-10 does this and it works flawlessly.
Also, if the tubes have been changed many, many times, occasionally I've seen the tube socket solder connections get weak. This has been mainly from me swapping tubes in and out constantly so that I can tell my customers what tubes work best with what amps.
Hope this helps.
Forgot to mention:
Make sure you are using a chop stick or drumstick or something that does not conduct electricity to tap on things!
Pencils will conduct electricity and there will be a couple of hundred volts on some of the parts that you are banging on. It really hurts!
Make sure you are using a chop stick or drumstick or something that does not conduct electricity to tap on things!
Pencils will conduct electricity and there will be a couple of hundred volts on some of the parts that you are banging on. It really hurts!
Monsta-Tone said:
Hmmm... the tapping comes through the speaker on a number of components but REALLY loud on just those few. If that's normal, then I haven't found the problem.
That may be possible, I re-soldered all the power tube socket connections last time round, should I redo the preamp tube sockets as well?
The noise is a lot of background hiss and a little hum coming primarily from the Rhythm channel and just a bit from the lead channel. It's quite a loud hiss even at 4-5 on the master volume.
Thanks for the help, Monsta
Well....hiss is normal if the gain is turned up, or the channel master is turned up very far. Say, over halfway.
I would definitely take a look at them, and I would also clean and re-tension the tube sockets. Most amps that I've see have issues with tube sockets if they have been run for extended periods of time at high volumes.
Make absolutely sure you discharge the filter capacitors before you spray anything into the sockets or re-solder anything.
I would definitely take a look at them, and I would also clean and re-tension the tube sockets. Most amps that I've see have issues with tube sockets if they have been run for extended periods of time at high volumes.
Make absolutely sure you discharge the filter capacitors before you spray anything into the sockets or re-solder anything.
Monsta-Tone said:
I suppose I would need a good working DC-3 to be able to make a comparison. Seems strange though, that the majority of hiss is on the Rhythm channel, I would have expected the lead to have more.
Would that be like running it 4-5 hours straight in a band situation, or more?
Will do, great advice. Thanks.
Well, like I said, if you run the gain and volume up really high, the channel will hiss.
Tubes can cause hissing as well.
As for the time, I mean for many 6-8 hour sessions.
DC-3's are notorious for running pretty hot. I installed a Mark IV fan in the one I used to have.
You can also avoid overheating by using a desktop fan and not placing the amp's back against anything.
It really sounds like something is turned too high or a tube issue. I have seen resistors make noise though when they get older, but Mesa uses really high quality ones.
I have never seen a resistor in a Mesa cause hiss unless it was straight up broken. Vintage Fenders, on the other hand, use carbon composition resistors and are very prone to hissing.
Tubes can cause hissing as well.
As for the time, I mean for many 6-8 hour sessions.
DC-3's are notorious for running pretty hot. I installed a Mark IV fan in the one I used to have.
You can also avoid overheating by using a desktop fan and not placing the amp's back against anything.
It really sounds like something is turned too high or a tube issue. I have seen resistors make noise though when they get older, but Mesa uses really high quality ones.
I have never seen a resistor in a Mesa cause hiss unless it was straight up broken. Vintage Fenders, on the other hand, use carbon composition resistors and are very prone to hissing.
Monsta-Tone said:
I thought it might be tubes also and swapped out all the preamp with new ones and the power tubes from my other amp, which are fairly new also, didn't seem to change anything.
I will revisit that again to make sure. Thanks.
Tubes seem fine as I checked them all again, but I found some more interesting info to the problem.
The Rhythm 'Gain' pot shuts off when you turn it up to 10, both Gain pots were a little noisy, could use some Detoxit. Should the Rhythm Gain pot be replaced? These pots also appear to be generating the most hiss, more on the Rhythm channel than the lead.
The Reverb pots on both channels produces a loud hum. The hum decreases some when you take the V5 tube out. The hum remains when the Reverb pan is hooked up but the sound changes somewhat.
The Rhythm 'Gain' pot shuts off when you turn it up to 10, both Gain pots were a little noisy, could use some Detoxit. Should the Rhythm Gain pot be replaced? These pots also appear to be generating the most hiss, more on the Rhythm channel than the lead.
The Reverb pots on both channels produces a loud hum. The hum decreases some when you take the V5 tube out. The hum remains when the Reverb pan is hooked up but the sound changes somewhat.
It's a good idea to clean all of the pots, but if it happens with the Reverb and Gain pots, I'm gonna say that you should also check the grounds for all of the pots that have them. Should be the right side lug if you are looking into the amp from the front.
If the Gain is cutting out completely, then that pot may be bad, but with the Reverb pots acting up, it sounds like a different problem.
Use a multimeter to check all pot grounds to the ground tab that is screwed onto the top of the amp. The shiny copper thingy.
If any of the pots that have wires on the right lug do not have a good connection to ground (under 2 ohms) then you might look at these solder connections. You should also be able to follow the traces on the board to make sure that all connections are good and that the wire leading from the board to the ground is good.
Other than that, it's a little hard to help without looking at it. Sorry.
If the Gain is cutting out completely, then that pot may be bad, but with the Reverb pots acting up, it sounds like a different problem.
Use a multimeter to check all pot grounds to the ground tab that is screwed onto the top of the amp. The shiny copper thingy.
If any of the pots that have wires on the right lug do not have a good connection to ground (under 2 ohms) then you might look at these solder connections. You should also be able to follow the traces on the board to make sure that all connections are good and that the wire leading from the board to the ground is good.
Other than that, it's a little hard to help without looking at it. Sorry.
Hope your squared off with the DC-3 issue. Question: I have same amp. Under no load all controls zeroed out. Amp is put on and unreasonable static is present gets worse the longer amp is on. Any ideas??
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You could try cleaning the tube sockets just by pulling them out and putting them back a few times. Techs also use an electrical contact cleaner while doing this. If that doesn't solve it then suspect you may have a bad tube somewhere and you might need to troubleshoot with known good tubes. Mesa offers this (see vid at the bottom):
https://mesaboogie.zendesk.com/hc/en-us/articles/216599018-How-can-I-troubleshoot-tube-issues-
If after that point you are still having the same issue you can assume it is another component or set of components and you might need to get it to a tech. Don't try to fix these things yourself unless you are experienced in doing so.
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I switched out the 84’s lost the static and breaking up…..after playing for about 1.5 hours at the following in Rythum channel only:Gain 3 , master gain 3 and main output at 1.5. The amp began to loose power and after turning up main out to 4 no change, continued to drop in power, distort stalky……..THEN WOW….. THE AMP SPONTANEOUSLY KICKED INTO A LEVEL SO HOT FROM THE POWER / signal loss it was experiencing, when that kicked in near blew me off my stool. At this point the amp performed flawlessly for hours,UNTIL I shut her down, next day experienced power loss after 1.5 hours but lesser extent. I also had some breaking up. I put it on standby and after 1/2 hour played again for several hours , normal power and no noise. This is very frustrating….possibly a POWER TUBE? Any ideas what to try next?
Thanks to everyone.
Dennis
Thanks to everyone.
Dennis
