| Author | Message | ||
     Anthony Hennessy (franzoni) Username: franzoni Registered: 01-2008 |
Hi all been a while.. A bit of a strange problem with my 130 HD 2x12...been having some intermittent problems as in pops,crackles and power loss..i did a complete cap job a while back but i also found the reverb started working again for some reason..???..(had a tank out of an old peavey in there in the past to try get it going)...for years i used the amp it with no problems and had the cables to the RCA jacks reverb disconnected so i'm not too pushed if the reverb works or not.... it started cutting out during a gig a while back so i used the Marshall on it's own for a few months(i use a two amp rig) brought the MM on a whim to a gig as it seemed to be beheaving itself at home and got 6 months out of it with no problems until last july...same again been using it around the house again and once again no problems and i play pretty loud at home...master is up around 7 and the preamp about 5...reverb is completely diconnected and i cleaned all jacks,tube bases etc....sorta want to get the old girl back into my rig with the superbass head as i like the way it fills in the EQ with the marshall in parallel....i just finished playing the HD 130 for nearly two hours earlier so it got well hot and used as during a gig with out a single pop or squeak.... so my question is could the reverb path be the problem with these amps as i've read of other members of the forum having problems..i.e if the signal is in series and all of it goes thru the reverb tank..or could it be some of the transistors starting to go...? this would be a real bummer as i wouldn't know where to start... Like i said if it is just the circuitry for the reverb i can live with that...any ideas or theorys much appreciated Cheers Tony | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I wouldn't think the reverb has anything to do with the loss. More likely a dirty component, flaky solder joint, dirty pot. COULD be a cracked resistor, as the carbon comps are getting old. You might have to do the wack test with the probe(insulated-chop stick-NOT a pencil) and find it that way. BE CAREFUL><><> Usually, transistors work or don't. If they have PLUG IN bases, thsoe could be dirty also. I think it's corrosion at some point, be it solder or component. | ||
| Anthony Hennessy (franzoni) Username: franzoni Registered: 01-2008 |
Howdy from Dublin Mike....! Thanks for that... it's a bit of a strange and frustrating one as the amp can work for months then go bad for a while...i will get a chop stick and do as you suggest... Maybe the old girl is just letting me know she wants a rest every now and again after 20+ years gigging....!! Regards Tony | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Like I said-BE CAREFUL. Those of us that do this all the time even get a little lax and do stupid stuff(a blown up 130 watt chassis in my shop comes to mind....long story). It's reall easy to get knocked on your ass or worse, and I wouldn't want to be the cause of that but sometimes. it's neccessary. Right hand only, left hand in pocket while wacking. Wood or plastic only, no pencils. That amo should have some 2 watt resistors across two pins on two power tubes that can get scratchy and noisy. Also, make sure you clean the sockets that the IC's are in. The little round ones on the main circuit board. I still think it's more likely that it's power tubes socket related but a preamp circuit loss can sound the same. Let me know. By te way, you didn't say if it was a 12ax7 PI or the SS driver. Which one? MIke. | ||
| Anthony Hennessy (franzoni) Username: franzoni Registered: 01-2008 |
Hi Mike... Sorry it the PI version...the serial no is COO3354..and obviously the Export version as i live in Ireland...100% with you on the H&S aspect as i got a little belt when changing the caps on the little sub board a while back.... I didn't know about the IC's being in sockets so i will check them out and give them a clean.. it's not so much noise as the whole amp drops in power/volume after about 20 or 30 mins.. I had a replating issue a while back that you helped me on and i changed all the caps and tube and it was good for a while after that,i've heard horror stories about Tranformers developing faults after an issue like that but i'ver also read that tranformers are tougher than people think especially in these older amps where everything was over engineered...?... Mike i will come back to you and let you know the outcome one way or the other.. Again thanks for the help and to Steve for hosting the site.... Regards Tony | ||
| Anthony Hennessy (franzoni) Username: franzoni Registered: 01-2008 |
Just updating as promised... Since my last post the amp has been fine with no issues,couldn't find anything in particular that weas wrong or looked dodgy but then i'm not expert on that part of amps......only using it at home but i'm thinking about using it on gigs again in a stereo setup with the Marshall as i miss the 'twang' the MM provides to the tone... very strange and frustrating problem but if i get 6 months like the last time before it needs a little 'rest' i'll be happy.... | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Hope it stays working for you. Mike. | ||
| Anthony Hennessy (franzoni) Username: franzoni Registered: 01-2008 |
Hi Steve,Mike and all Another update.... been using the amp pretty regular in the house for about two or three hours at a time with no issues until last night....plugged in the connections for the reverb tank and all was well ..turned it on this morning and after about 25 mins i had some funny whistling noises and the whole chassis of the amp was touch sensitive.... Disconnected the reverb again banged the top of the amp with the side of my fist a few times and the touch sensitivity went away and all was back to normal....! Think i'll just save up for a reverb pedal....  .. Thanks again Tony | ||
| Anthony Hennessy (franzoni) Username: franzoni Registered: 01-2008 |
Hi all Think i might of traced this to the output jacks...i changed the cable a few years back and put a neutrik right angle jack on some with some heavy duty speaker cable...the other night it was making a bit of noise again and when i was tapping the amp put my hand on the output jack and it stopped..have done two gigs with the amp and it's been ok ... strange.....i think i remember a post on this forum where someone said there was a problem with the output jacks..? | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Don't really remember but I'm old and prone to being stupid. Anyway, jacks get corrosion, dirty, wear out if you use them etc. I would just replace them here and be done with it. I personally never used the footswitches with any of my amps as I never used verb unless external and use my pedal board for everything. Never used trem either. Don't think my footswitch has ever been plugged IN now that i think of it. Not even sure where they are at at the momemt! | ||
| Anthony Hennessy (franzoni) Username: franzoni Registered: 01-2008 |
Ha ha... hear ya on the footswitch .. ..cheers Mike... i'm in the process of getting a reverb pedal and have a tremolo pedal already although you can get a cool sorta of uni-vibe with MM's built in tremolo at a very a slow speed and low intensity... will do on the jacks.. Merry Christmas and a peaceful new year to all here.. Regards Tony |