Bonesaw Bazz Posted January 23, 2008 Report Share Posted January 23, 2008 Yeah so i have a Peavey 5150 imported head, running through a tranny. When i got it, i had it checked over by a tech who replaced 2 valves which had been broken in transit. Otherwise, was informed by him amp was in tip top.So recently i noticed that after say, an hour of use. The volume dramatically drops. This is obviously easy to live with for gigs etc but... i'd kinda like to get that sorted out. Anyone advise what the problem might be? I'll still call the guy i used previously but he lives in Edinburgh practically!!!!Cheers the NooBazz Ooka Quote Link to comment Share on other sites More sharing options...
sonhenry Posted January 23, 2008 Report Share Posted January 23, 2008 There's bunches of things that could cause that, might be best to get a pro to look it over. Might be a cold solder joint, so you could try opening it up and re-soldering all the connections, but the caps in a tub amp carry LETHAL voltages, so if you're not sure, spend the cash to have it done by someone else.That said, it could be a short, it could be a bad valve or a cap problem. I'd start with the resistors attached to the valves themselves. Check the values of them and the connections, testing the connenctions by bumping it with a pencil. Quote Link to comment Share on other sites More sharing options...
Bonesaw Bazz Posted January 27, 2008 Author Report Share Posted January 27, 2008 There's bunches of things that could cause that, might be best to get a pro to look it over. Might be a cold solder joint, so you could try opening it up and re-soldering all the connections, but the caps in a tub amp carry LETHAL voltages, so if you're not sure, spend the cash to have it done by someone else.That said, it could be a short, it could be a bad valve or a cap problem. I'd start with the resistors attached to the valves themselves. Check the values of them and the connections, testing the connenctions by bumping it with a pencil.Ah cheers dude. I forgot i posted this! haha Sounds a bit too technical for me. I'll either break it or die. Will it be okay to keep using or should i avoid this till i get it looked at? Quote Link to comment Share on other sites More sharing options...
sonhenry Posted January 27, 2008 Report Share Posted January 27, 2008 I'd get it looked at, especially if you're gigging with it. Quote Link to comment Share on other sites More sharing options...
Lame Guitarist Posted January 30, 2008 Report Share Posted January 30, 2008 change your 6L6 power amp valves, one of the main causes of faults in 5150's and specially a drop in volume. and check the solder connections on your speaker cab jacks as well. I had a guy come to me saying his amp kept losing volume and cutting out as well. Checked the head and it was fine so i asked to see his cab. He had a dodgy solder connection on his marshall 4x12 that was causing it. Quote Link to comment Share on other sites More sharing options...
Bonesaw Bazz Posted January 30, 2008 Author Report Share Posted January 30, 2008 Yeah most feedback seems to suggest a change in valves. I use different cabs all the time and different outputs from the back of the amp just to check that. So defo seems a issue with the head. Now the fun begins. where the fuck do i get valves from? Being a complete novice here.. but ain't they kinda specific to each head? Quote Link to comment Share on other sites More sharing options...
Lame Guitarist Posted January 30, 2008 Report Share Posted January 30, 2008 Yeah most feedback seems to suggest a change in valves. I use different cabs all the time and different outputs from the back of the amp just to check that. So defo seems a issue with the head. Now the fun begins. where the fuck do i get valves from? Being a complete novice here.. but ain't they kinda specific to each head?watford valves! dont order from peavey as your getting their name brand which is actually usually sovtek for double the price!!!speak to derek at watford and tell him what amp you have and he will keep you right. it should be 6L6 valves you have in there but its down to what kind of sound your looking for when it comes to the brand. Quote Link to comment Share on other sites More sharing options...
Alkaline Posted January 30, 2008 Report Share Posted January 30, 2008 watford valves! dont order from peavey as your getting their name brand which is actually usually sovtek for double the price!!!speak to derek at watford and tell him what amp you have and he will keep you right. it should be 6L6 valves you have in there but its down to what kind of sound your looking for when it comes to the brand.Agreed, Watford were very helpful when i replaced the valves in my DSL100. Couldn't recommend them more. Very quick delivery too. Quote Link to comment Share on other sites More sharing options...
Bonesaw Bazz Posted January 30, 2008 Author Report Share Posted January 30, 2008 sorta price we looking at? Quote Link to comment Share on other sites More sharing options...
Lame Guitarist Posted January 31, 2008 Report Share Posted January 31, 2008 sorta price we looking at?all depends on the quality of valves you decide on, i would say average since its 4 6L6's about 60 notes. by the way change your fuses as well inside the amp. dont be worried about shock as the 5150 discharges itself after its turned off pretty well.theres small glass fuses in there around the circuit board. its usually best to replace them to new ones after a tube change. you can pick up the same ones from places like maplin electronics and they only cost about a couple o quid for a packet Quote Link to comment Share on other sites More sharing options...
stuartmaxwell Posted January 31, 2008 Report Share Posted January 31, 2008 even though they are one of the cheaper sets, I have found JJ 6l6s to be great and they supposedly last longer than most other types of valve. Quote Link to comment Share on other sites More sharing options...
Lame Guitarist Posted January 31, 2008 Report Share Posted January 31, 2008 even though they are one of the cheaper sets, I have found JJ 6l6s to be great and they supposedly last longer than most other types of valve.havent tried the power valves but the JJ preamp valves have a nice sharp and clear sound Quote Link to comment Share on other sites More sharing options...
Soda Jerk Posted January 31, 2008 Report Share Posted January 31, 2008 I had the same problem.Is the head second hand? I replaced the PCB beneath the valves with a handwired Point to point circuitry. Contemporary valve heads tend to be really cheaply put together when it comes to the transistors and the cheap, shitty chinese PCB's they use. Handwiring it yourself will cost you nothing more than 30 and a Sunday afternoon. It will make it much more resilliant and give it a boost of clarity in your tone. Quote Link to comment Share on other sites More sharing options...
triggs Posted February 14, 2008 Report Share Posted February 14, 2008 my jcm 800 had a similar problem ....... i ordered a set of jj valves from hotrox, problem sorted Quote Link to comment Share on other sites More sharing options...
Soda Jerk Posted February 14, 2008 Report Share Posted February 14, 2008 Did you get both JJ power and pre amp valves?Their power tubes are alright, but their preamps really don't last. Quote Link to comment Share on other sites More sharing options...
Bonesaw Bazz Posted February 14, 2008 Author Report Share Posted February 14, 2008 I still have to save enough money before i can even look into this really. Anyone know a Tech in Aberdeen per chance?Bazz Quote Link to comment Share on other sites More sharing options...
Lame Guitarist Posted February 14, 2008 Report Share Posted February 14, 2008 I still have to save enough money before i can even look into this really. Anyone know a Tech in Aberdeen per chance?Bazzi can have a look at it for you if youwant. have you tried new valves in it? Quote Link to comment Share on other sites More sharing options...
Jeid Posted February 14, 2008 Report Share Posted February 14, 2008 I have JJ valves in my preamp... they're quality. Quote Link to comment Share on other sites More sharing options...
Bonesaw Bazz Posted February 14, 2008 Author Report Share Posted February 14, 2008 i can have a look at it for you if youwant. have you tried new valves in it?I haven't touched it dude. Still as & where it was when i started this thread. Dinna want to make it worse. It's at Captain Toms just now, but i can meet you there or take it to you whenever suits bud. Be much cheaper than taking it to Fife!I spoke to the Valve company that was recommended earlier.. the just said to get a Tech to have a look at it. So i guess once i get it checked over and confirm it's defo the Valves. I'll talk to them again and sort out some nasty sounding yins.CheersBazz Quote Link to comment Share on other sites More sharing options...
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