Is my 50/50 fried?

[The Magic Hoof]

Here's the deal. I've been struggling to get a decent recording and tone out of my Quad+50/50 setup forever now to no avail. When I first got my 50/50 there was this static noise which you can check here - http://forum.grailtone.com/viewtopic.php?f=5&t=36729

As I was saying I've been struggling to get a good recorded tone, so today I whipped out my Quad+50/50 and decided to crank it. I put the knobs on channels A and B on the 50/50 to about the 4-5 setting, so it was pretty loud for where I live. Suddenly I heard these popping/crackling noises all the way in another room, so I went into the room to turn the amp off in case if it was about to explode...... then I smelled something burning and heard the 50/50 sounding like it was taking its last breath, like it was gurgling. Currently, it isn't getting power at all and won't turn on. I'm not sure what to do to fix it and how to find out what's wrong with it.

Gear breaks and that sucks, yeah, but what I want to know more than anything is how I haven't gotten a good tone out of my setup for this long considering I have good gear. I'm wondering if it could have been the 50/50 all along that was the culprit...

And honestly, even though I really don't want to, I'm at the point where I'm contemplating getting rid of all of my Mesa gear and switching brands, going with something like a Peavey which is a decent little metal amp. Just kinda tired of fooling with and struggling with the Quad and 50/50

 

[MesaGod666]

Ouch. Sorry to hear about that broseph. Couple of questions:

1. Were you using a power conditioner?
2. When was the last time you had it retubed?

It sounds like it's dead. So, take it to your local Mesa tech and have them do a postmortem. Perhaps, they can resurrect it or at least tell you what went wrong. As far as the new amp goes...get a Triaxis and 2:90. I firmly believe that it is the best sounding setup ever...next to the ENGL rack mount amps of course.

 

[The Magic Hoof]

I wasn't using a power conditioner, no. I couldn't tell you about the tubes because I bought both the Quad and the 50/50 just a few months ago from different sources. The Quad seems to be A-OK, but the 50/50 had trouble upon first receiving it like noted in the noise thread.

I think it may very well be entirely possible that the Quad+50/50 rig just won't and ain't gonna cut it for what I'm trying to do, which is a high gain metal rhythm sound. I actually have a boost pedal in the mail on its way to me right now. I bought it because I thought it may help push more gain and boost the presence/saturation in the cab for getting that FULL metal tone, but egh, my 50/50 is burnt now.

So yeah, I think it may be a good idea to just move on and get a Peavey 6505 or something. I'll test my Mesa cab to see if it's working ok, and I'll hold onto the Quad just to keep around. I dunno what I'll do with the 50/50, but we'll see.


Regardless of anything, getting a fully saturated, present, full metal tone out of the Quad+50/50 has been impossible up to this point.

 

[leadfootdriver]

A great tip is to always use contact cleaner when changing power tubes. No matter what! Trust me on this. :!: Give the pins, and the tube socket a good wack of contact cleaner, and work the tube in and out a few times to establish fresh contacts.

I'm not sure what happened with your amp, but what usually happens when a power tube dies hard, is that it takes down a screen resistor with it. Look in the amp for anything chared, or burnt. It's a common, and an easy fix. YOu could do it yourself if you're so inclined.

Don't touch any bare contacts if you don't know how to discharge filter caps. YOu could die, and I ain't lying.

 

[The Magic Hoof]

To be honest I'm so bummed about getting all of this Mesa gear working for months and months that I'm ready to just charge up another amp on a credit card, something like a Peavey 6505 or something. I think I might hold onto the Quad preamp no matter what in the meantime. In the future I'll probably get the 50/50 fixed or somehow end up with another power amp and figure out what the problem was.

I love Mesa's tone, no doubt, but I'm ready to just bite the bullet since I'm sick of running into so many problems with all of it. It'll be better to have something else that sounds decent and works at all than to fool with the Mesa gear any longer, for right now.


By the way, not even the LED is coming on on the front of the power amp, and the fan isn't spinning. I'm not sure if it still gets power if a/no tubes are working, but the power isn't working whatsoever.

Look like one of the tubes is bad. I didn't see anything else on the circuitboard that looks discolored at all.

 

[leadfootdriver]

That tube looked like it shorted out. Did U blow a fuse? The 4 brown resistors that run horizontal along the back are the screen resistors.


Sell me ur Quad if you decide to off it.

 

[The Magic Hoof]

I'm not going to get rid of the Quad just yet . I'm not sure how to tell if I blew a fuse... how do I do that?

 

[leadfootdriver]

How old is that thing? Does it have a bias switch for the el34's u have in there?

 

[The Magic Hoof]

I have no idea what a bias switch is :lol: . It's from '89, as you can tell from in the picture.

 

[leadfootdriver]

Those are el34's right? Unless u had had the amp rebiased for el's, it will only take 6l6's and not blow up.

 

[The Magic Hoof]

I actually have no idea. I just bought it and was told it came with the original-type tubes. How do I check for a blown fuse though?

 

[crane]

There's a fuse socket beside the power switch. Open it (1/4 turn) and check the fuse.
Take a look at your tubes and be sure they are 6L6GC. Your tubes are JJ, not original Mesa. It's possible that they aren't the good grade for your amp. Replace them with Mesa or install a bias mod like I've done (check my posts).
If everything is ok you can start checking power cable, inside solders, ...

 

[jaquetapus]

If you've never even checked the tubes, it's time to replace them. Go get a set of Mesa 6L6's and a handful of fuses and swap them out. If the fuse blows again, there's obviously something else wrong. But it sounds [and looks] like you may just have a bad tube. No sense in junking the whole rig over a tube. If you're not interested in going through the trouble, I'll take the 50/50!

-dave

 

[The Magic Hoof]

I'm eventually going to fix it. Let me clarify though - If the power isn't coming on at all, as in the fan isn't spinning and the blue LED isn't coming on, will just a single tube cause it to do that? Because I thought a tube going out wouldn't affect it to where it won't turn on at all.

I'm about to take a look at the fuse and see what's up. Never done this before so wish me luck. I've got to find a place to get those Mesa tubes and fuses from... can someone point me into the right direction?

 

[The Magic Hoof]

UPDATE - They are all JJ E34L tubes. I have no idea what a bias switch is or where to find it in the 50/50. Also, the fuse thing on the front is broken. The twisty thing tore off and I had to screw it up to get it off/out at all. No wonder the guy sold it.

I'm not sure if the fuse is actually blown or not. There is very slight discoloration in it, so I'm not sure. Also, should I worry about those smaller tubes in the 50/50? Three of them I think.

 

[crane]

1/ replace the fuse with the same type.
2/ throw away those E34L, they aren't the right tubes for your 50/50 ! They draw too much current and may kill the power tranny. I hope this hasn't already happend !

 

[jaquetapus]

Let me clarify though - If the power isn't coming on at all, as in the fan isn't spinning and the blue LED isn't coming on, will just a single tube cause it to do that? Because I thought a tube going out wouldn't affect it to where it won't turn on at all.

Yes, a single tube can do that, because it blew the fuse. Blown fuse means no power for anything. You should be able to find that fuse holder relatively easily, through a Radio Shanty or your local Boogie tech/dealer.

 

[The Magic Hoof]

Let me ask some things.

The seller had 100% feedback on Ebay so I took it he was a Boogie guy. Since that's so it's leading me to believe that there may be a bias mod on the 50/50. How do I check for one? Because if there isn't one I'm going to wonder why on Earth the wrong tubes are in there.

If the wrong tubes are in the power amp, could this have been my problem all along as far as getting a powerful, full, rounded tone out of it? I'm starting to wonder. Though, I'm still not sure if I should even bother with any of it... we'll see though. I want to know how to check for that bias mod and know if the tubes in a power amp can cause the probems I've been describing.

 

[The Magic Hoof]

By the way, the fuse type is 3A/250v. Can I get these from just anywhere? RadioShack etc? And are they the 6x30mm variety? There are different sizes but I'm guessing it's the 6x30mm size.

 

[crane]

Getting a nice round, full sound from EL34 is harder yes.
ITo see if there's a bias mod in your amp, check my post :

http://forum.grailtone.com/viewtopic.php?f=5&t=32130