Randall RM4 help

[goalkpr101]

Hey Guys,

New to the board and I apologize that my first post has to be because Im having problems with my preamp.
I have a Randall RM4 running with a Mesa 50/50 poweramp. My volume keeps dropping on me. After about 10-15 minutes my volume goes from 100% to 50 then to about 10%. If I keep playing it comes back up, then down again. It also gets really scratchy with staic during this period. The only way to get it back up immediately is to shut the RM4 down and restart it. Im wondering if any one has had a similiar problem and if it might be tube related. Im not getting any microphonics but between the 4 power tubes and 3 12AX7s in the Mesa and the 3 preamp tubes in the RM4 and the 8 preamp tubes in the Randall modules I just dont know where to start. I have tried to isolate the problem by pulling 1 module at a time to see if the problem goes away and that wasnt it and all the tubes are lit but nothing seems to stop it. Any ideas would be really appreciated. I just cant play out wondering when it going to rear is ugly head.

Thanks

 

[TOStudent]

http://mtsforum.grailtone.com/index.php ... a9db9ff63d

Try here you'll get all the help you need. Great site Randall MTS specific.
okstrat is the only Randall MTS user that I know of here. Otherwise you probably won't get too many replies.

On the site above all that is over there is Randall MTS stuff.

Hope that helps.

 

[Audioholic]

Best bet is to start trying to isolate the problem. For instance, does it happen on all 4 different slots and modules, or only one in particuliar? If it is a common occurrence on all 4 slots, then you move onto the tubes on the RM4, you can just swap out one at a time to see if the problem is still going on. Still going on? then move onto yoru power amp. Something like this its best to just try to isolate and follow the clues that will hopefully lead you to the culprit, be it bad tube, faulty RM4, etc etc.

best of luck


be sure to even check yoru cables to mate.

 

[jkdsteve]

cold solder joint?

loose power connection? (there are a few internal spade connectors and also a ton of push on board connectors..these are usually bonded in place tho')

I think the RM4 has a rear input - does it also do it if you connect there?

I'd narrow it down by just using one module in slot 1 if you're messing with tubes........it sounds like your power amp is good if power cycling the RM4 brings it back to life.