Pop, snap, odd sounds then works fine.

My amp began making odd sounds for about 45 seconds to a minute after turning it on. I unplugged everything except the speakers. I changed all the pre-amp tubes one at a time and all 4 of the power tubes with no change. It happens in both the 45 and 90 watt settings but NOT in the 10 watt setting. It is not channel specific as it happens with all three of the channels. It starts about 3 seconds after I take the amp off of standby and lasts right about a minute or a little less. Then everything tapers off and the amp works fine. Any ideas?

Could be dirt inside the 2 output valve sockets, furthest from the power transformer.
They're not used at all when the amp is in 10watt mode. They only have the heater element running.
If you're going to go spraying cleaner in there. Or poking around (something I don't recommend), please ensure the amp is fully discharged beforehand.

It's in the Shop... The Boogie Shop...Hollywood. We shall see what was wrong in a few days.

Mine did something similar, was some bad components in the power transformer.

Hope they get you fixed up soon!

It's fixed. It was ready in less than a week (it was fixed in two working days I just could not get there any earlier than a week.

So, what was the problem? I'm sure we would all like to know.

Thanks,

TW

I was told the power tubes were the issue. It works fine now so I'm good. I am glad it was not a big deal as I push things on outside gigs. It sounds very nice when pushed with a crisp attack and beautiful sustain. I love the dynamics of the amp, how the attack stays sharp but has a nice texture with the volume backed off a bit. It is a very reactive amp.

I did a gig while the Mark V was in the shop. I used my Boogie F-30. It's a little work horse but I was backing off the bass and treble, cranking on the Mids and using the scoop switch for leads. It worked very well, surprising actually but.... it's no Mark V.

I have taken the Mark V to small gig's. Set it at 90watt, back off the channel volume...way off. Bring up the output for the room and it sings at low volume level.

OldTelecasterMan said:

I have taken the Mark V to small gig's. Set it at 90watt, back off the channel volume...way off. Bring up the output for the room and it sings at low volume level.

Click to expand...

Hehe...I do the same.
I thought I would be using 10 or 50W for smaller venues but it never sat right for my ears.

Glad you got it worked out and it was nothing major.

So you're saying you take down each channel volume instead of the master, when playing lower volume gigs? Interesting. Before I got mine, I read so many people say to "keep the channel volumes up to around noon and turn down master for best tones" that this may be the one thing I haven't really experimented with yet on my V.

Anyway, glad it's up and kicking butt again!

My opinion, my ears hear better tone with the output up, channel volume down. When I was test driving the amp at Mesa Boogie the guys that worked there basically set it up. They explained what they were doing and why. Straight from the guys at Boogie " While you are learning what sounds good to you, Start with the Output at 12 O'Clock and then adjust the channels."

I have gone from gig to gig, out door, indoor, small room, big room and never touched my channel volume in months maybe a year. I must admit in big rooms and outdoor gigs where I get the amp up around or over half, a couple of times I got up to about 2/3 on the output.... The amp really sings and I cannot discount the fact that I'm standing in front of it so there is of course much more guitar interaction. Making the Output tubes work gets the amp into a very nice place.

Thanks for the tip. I'll try that.

Makes sense, the amps biased cold. So upping the master would push the output valves a bit more. Keeping the channel volumes down stops the output section seeing as much of the pre-amp section as it could. So you still have loads of clear headroom. Sort of a hifi way of doing things.

My thought was in a channel you have a gain and a volume. Why would I want to overdrive into my power section? Running a bunch of signal into the power section made things really touchy when adjusting anything. Also that "Ice pick" that everybody speaks of is just gone.

Of course too much of a good thing is not good either. Running the amp output wide open is a No No also.

Well there's still call for it. Vox for instance, the secret of that sound is there is absolutely no negative feedback going on. Winding up channel volumes and hitting the power section hard get's you a long way into that territory. What negative feedback does is take a portion of the signal to the power amp and feed it back into the pre-amp. As you turn the presence dial up, more negative feedback (NF)\

A few years back I modded my JVM(that I later gave away) to have a load of different Marshall amp types of presence control. From the NF loop. Plexi (most) 900, EVH, 800 and Vox type. As all those Marshall power sections are essentially the same. Bar the resistor on the NF loop.
Made for a very responsive amp.

I'm trying it. So far so good, but... as with the discussion about the loop on vs off... you have to VERY carefully balance the volume each way before you can really tell if one way is better than the other. If you don't get them EXACTLY the same, the louder way will almost always sound better. So far though, so good. It will take a while to A/B it each way and will all three channels. Noon on the channel volume and 10-ish on the Output, vs. Noon on the Output and 9-10 ish depending on channel, on the channel.

Anyone else already tried this both ways and settled on a "better" sounding way? I would have sworn that most of my reading prior to owning the V, said "channel volumes up around noon, then Output to taste." I realize we're off topic here...

I have gotten used to the sound of the amp with the FXloop active. I basically set the master about 9ish to 10 oclock. I will adjust the masters of each channel to suit ( about the same or closer to noon) all depends on master volume level and the amount of saturation I am after.

I have tried to run the amp without the FXloop active. I did not really like it that much as I found it harder to normalize each channel. Also when turning on the amp, I normally drop the volume to cut the typical noise down one the tubes warm up. I may need new tubes. I also fee the same about the Roadster using the FX loop vs having each channel as its own master. Since I have gotten used to the amps using the FXloop, I am not taken away but the differences with using pedals in the loop. Mark V may require line level compatible effects as some will alter tone and compress the signal since they were designed for instrument level only.

The two amps that I have which do not have a single master capability for each channel would be the JP-2C and the RA100. The balancing act with those to amps is not difficult. Also note that these are basically set internally with the loop active and the JP the only one of the two that can switch it on or bypass the loop with a switch or midi controller.