HELP!!! MOD50 Channels 3 & 4 shot!!!

[bbaug14]

Back story:

My band had a gig last night. I fired up the MOD50 and checked everything out and it's working great. Put it on standby, have a few beers, and just hang out. Sound guy shows up about a half hour later. Click to high power, do sound check, gravy. Put the amp back on standby and have a few more beers. Go on stage, click over to channel 3, and all I get is a loud buzzing. Really loud. Try channel 4, same thing. Cycle power, try again, no change. Channels 1 and 2 are working great though. SL2 was in the second slot, so I think maybe it's a module issue, although I don't believe a blown tube would sound like this from past experiences with blown tubes in the modules. So, I pop in EG5, same thing. BMAN on channels 1 and 2 work fine, but channels 3 and 4 on the amp just give a loud buzz and that's it. I played the rest of the night with just BMAN and some stomp boxes, which certainly got the job done, but I'm perplexed as to what is wrong with my amp.

Please, if you have any idea what this problem is, chime in here. I'd like to fix this today, but I'm not really sure where to begin. I figure maybe it's a bad preamp tube in the head or maybe a blown fuse? Not sure what tube to change though or what fuse.

Thanks for your help in advance guys!!!!

 

[Val]

I would call Jeff at Egnater. I pretty sure they are getting ready for NAMM that starts on Monday, but give it a shot. They are very customer oriented.

 

[bbaug14]

Yeah, the shop is about a mile from my house. I know they are gearing up for NAMM and with the weather here in Michigan, I highly doubt Jeff will be at the shop today at all, so I think that's a no go. He's pretty involved on this board, so if he's in the shop, he'll see this thread for sure and contact me. I was just hoping someone on here had more information so I could get this taken care of on my own.

 

[Gino]

Did you try putting all of your modules in the second slot to see if the noise persists with them? You know BMAN works fine in slot 1, but does it change in slot 2? I noticed that the noise got louder when you went to channel B on SL2 and EG5. Last night Rob said the power at Fifth Ave is bad, especially stage left, where you were plugged in. Have you tried it at home or are you just going off of what happened last night? If you've got noisy power, it could've been amplified in the higher gain modules. Donnie said you were getting noise on BMAN (I'm going to assume when you had the OCD on) still so that could still lend itself to the power issue. Do you have any kind of meter to check fuses or tubes? I could bring mine over today.

 

[bbaug14]

Did you try putting all of your modules in the second slot to see if the noise persists with them? You know BMAN works fine in slot 1, but does it change in slot 2? I noticed that the noise got louder when you went to channel B on SL2 and EG5. Last night Rob said the power at Fifth Ave is bad, especially stage left, where you were plugged in. Have you tried it at home or are you just going off of what happened last night? If you've got noisy power, it could've been amplified in the higher gain modules. Donnie said you were getting noise on BMAN (I'm going to assume when you had the OCD on) still so that could still lend itself to the power issue. Do you have any kind of meter to check fuses or tubes? I could bring mine over today.

I pulled the fuses today and checked them and they were fine. I also plugged in the amp just now and ran it through the motions and it seems to be working fine now. Maybe it was just a bad power problem. However, the only weird thing is that when we went through sound check and when I was setting up before that, I had the amp on and I was using it with SL2 on slot 2 and it was working fine without any noise issues or anything. Also, in slot 2 last night with EG5 and SL2, when I tried to play something right before we went on when the buzzing started, everything I played either wasn't coming through at all, or when it did come through it was very weak/quiet and intermittent. I have no idea why that happened. Also, when that did happen, I switched to BMAN on slot 1 and I wasn't getting anything either. When I cycled power, slot 1 was fine again. Very strange. Too me, this sounds like more than just a bad power issue, but I could be wrong.

 

[jmgman69]

Did you try putting all of your modules in the second slot to see if the noise persists with them? You know BMAN works fine in slot 1, but does it change in slot 2? I noticed that the noise got louder when you went to channel B on SL2 and EG5. Last night Rob said the power at Fifth Ave is bad, especially stage left, where you were plugged in. Have you tried it at home or are you just going off of what happened last night? If you've got noisy power, it could've been amplified in the higher gain modules. Donnie said you were getting noise on BMAN (I'm going to assume when you had the OCD on) still so that could still lend itself to the power issue. Do you have any kind of meter to check fuses or tubes? I could bring mine over today.

I pulled the fuses today and checked them and they were fine. I also plugged in the amp just now and ran it through the motions and it seems to be working fine now. Maybe it was just a bad power problem. However, the only weird thing is that when we went through sound check and when I was setting up before that, I had the amp on and I was using it with SL2 on slot 2 and it was working fine without any noise issues or anything. Also, in slot 2 last night with EG5 and SL2, when I tried to play something right before we went on when the buzzing started, everything I played either wasn't coming through at all, or when it did come through it was very weak/quiet and intermittent. I have no idea why that happened. Also, when that did happen, I switched to BMAN on slot 1 and I wasn't getting anything either. When I cycled power, slot 1 was fine again. Very strange. Too me, this sounds like more than just a bad power issue, but I could be wrong.

I think it's fucked up and you need to send it to me IMMEDIATELY!!!!!!

 

[EWSEthan]

Wow this is really strange! Im an amp tech moron so I cant really advise at all. If its bad power its pretty scary that this could happen to any one of us on a gig. If it is that, would something like a power conditioner mitigate that risk?

 

[Valtiel]

Its definitely not any sort of an issue with fuses. When a fuse blows, amp dosent turn on. Its also not an issue with the tubes in the head, if it was it would affect both modules.

I guess we'll have to wait for Jeff to chime in, I have no experience with the inner workings of the amp itself.

 

[Fallout Labs]

Wow this is really strange! Im an amp tech moron so I cant really advise at all. If its bad power its pretty scary that this could happen to any one of us on a gig. If it is that, would something like a power conditioner mitigate that risk?

not a power conditioner, a voltage regulator, like a furman ar-15.. its rack mount of course.

 

[muudrock]

Speaking from experience, the Mod series can be F'd up by bad power. I had problems in a particular venue with both the Mod 100 and Mod 50. Invest in a good power regulator like the Monster of Furman and you should not have those problems.
Sounds to me you were experiencing a swithing glitch.

 

[Gino]

... However, the only weird thing is that when we went through sound check and when I was setting up before that, I had the amp on and I was using it with SL2 on slot 2 and it was working fine without any noise issues or anything...

It's possible that something was turned on in between soundcheck and show time like lights, heat, etc. Something could've been on the same circuit.

Also, in slot 2 last night with EG5 and SL2, when I tried to play something right before we went on when the buzzing started, everything I played either wasn't coming through at all, or when it did come through it was very weak/quiet and intermittent.

This could still be indicative of a bad power issue. From what everything Rob and people here have said and the fact that everything is working fine now, the dirty power sounds like the culprit. Which sucks because we're going to be there in a month.

 

[bbaug14]

Guess I'll try plugging in on the other side of the stage with an extension and if that doesn't work I'll be getting a power regulator. Awesome.