[dhunte21]

Good Day,

I have a slight problem with my RM 9 MK II. IT seems as though, the easiest what to explain is a sort of static or popping noise in my right channel. First off I am an experience tech and have worked on many amp in the past. The noise used to go away as the amp heated up but it does not any longer. For starters it does not increase with volume.  I did change out all 4 of the pots. I swapped out the left and right tubes in both input and out put stage. I checked for any cold solder joints. It cant seem to find anything.

Have anyone here experienced a similar problem. 

Any Information will help..

Thank you in advance.

[underdawg]

time to check for leaking capacitors or just recap the amp which it may need anyway.

[Freo-1]

I had a Citation II that had the same type of problem.  Had to replace the coupling caps on the suspect channel. 
 
If the unit has some hours on it, may be be best to re-cap the entire unit.  Age and heat do catch up with all caps.

[Ericus Rex]

Check all the tracings on the PCB, they are delicate.  If you've rolled the drivers you may have loosened up the solder joints around the tube sockets.  A very common issue with this amp.  When you get the static, try lightly tapping on the tubes in the noisy channel to isolate.

[dhunte21]

I though about that, I did go over the PCB Trace with a fine tooth, and I did not see any problems there. The amp has low hours on it as it has been sitting for many years prior to being used. I do think that a re-cap is in order, but the funny thing is that I powered it up this morning and watched the amp. Just the amp was powered up. after about 10 mins or so I started to hear the little static in the right channel, the closest way to explain it is more like a a tiny popping noise. When it does it you can see the bias light flicker in unisance with the static/popping. You can only hear it when you stop playing music, it is quite low.

Any thoughts.

[Scottdazzle]

Two basic things to do when trouble shooting are to switch the left and right inputs. If the problem changes channels the problem isn't in the amp. Then switch the left and right channel tubes. If the problem stays in the right channel you know it's not a tube problem. Good luck.

[Ericus Rex]

Did you change the balance pots too?  (does the Mk II even have balance pots?)  Those pots went bad in my Mk I and caused a static-like noise.

[rbwalt]

i think they did have balance pots. trying to remember back when i had my MKII. sounds like it maybe a bad input tube or one of the sockets for them. they just work their way loose from the board. go back and check your work. as far as caps leaking roger's caps never usually have that issue specially since you said it has low hrs on it and sat for a long time. yea that board roger used was a crap. must have cost him very little and those pots are not good either. they are good for only about 100 turns according to roger.

good luck. when you get it all sorted out you will have one fine amp. had mine for 11yrs. had to have my pots replaced. tube sockets gone over. some resistors replaced along with the feedback switch replaced.

how many have replaced the crappy power cord it comes with?

[rbwalt]

if anyone would like to see what the insides of a RM9SE looks like then go to: gallery> albums> rbwalt. you can also go to systems>R>rbwalt.

i was talking with roger and he has i believe 7 brand new RM9SE amps for sale. when they are gone they are gone. he only made 18. i think he is keeping one for himself. this amp is the best that roger has ever made period! as good as the mkI and II's were and are this amp just poops all over them. roger also has a few RM1/2 pre amps for sale. i have never heard one but from what i am able to gather it is one hell of a pre amp.

[dhunte21]

You know I pretty much did all of the tech tips posted. New pots, Checked for leaking Caps, checked the traces on the board it just does not add up. I will pull it again today and have another look at the beast. 

I will keep you posted.

Thanks.

[Ericus Rex]

http://www.audiocircle.com/index.php?topic=114292.msg1192375;topicseen#new

[rollo]

http://www.audiocircle.com/index.php?topic=114292.msg1192375;topicseen#new

 Agree 100%, check those tube sockets man.

charles

[Ericus Rex]

And don't forget those pins either!   

[Roger A. Modjeski]

time to check for leaking capacitors or just recap the amp which it may need anyway.

 DON'T recap the amp. The only caps I have seen fail are the 22uf/500 Volt on the visible side of the PCB and when the fail they usually short so there will be no sound. Noise is often sockets and more often the input tube. Cleaning pins with a wire brush is recommended  then coat with red DeOxit and make sure they are tight in the socket. Socket pins can be tightened if necessary though I have replaced many driver sockets due to wear from tube rolling. The amplifier was not meant to be a tube tester and many users put random tubes into the V1 socket in the hope of finding the one out of 10 that may balance. We sell balanced tubes that I select is a special test fixture. http://tubeaudiostore.com/69lownov1for.html.

Anyone having balance problems or want a tube guaranteed to be in the center of the pot can get a premium balanced tube to determine if the pot and associated resistors are in spec. http://tubeaudiostore.com/prmiofupforr.html.