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[Bonesaw Bazz]

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 Noo

Bazz Ooka

[sonhenry]

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.

[Bonesaw Bazz]

Originally Posted by sonhenry

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?

[sonhenry]

I'd get it looked at, especially if you're gigging with it.

[lame guitarist]

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.

[Bonesaw Bazz]

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?

[lame guitarist]

Originally Posted by Bonesaw Bazz

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.

[Alkaline]

Originally Posted by lame guitarist

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.

[Bonesaw Bazz]

sorta price we looking at?

[lame guitarist]

Originally Posted by Bonesaw Bazz

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