help diagnose amp Peavey VK100 Head/chose new tubes

franz

Member
Messages
6
Hi
bought my amp a week ago used and was playing at moderate volume when suddenly my amp went completely off, a fuse blew and it went completely dark, after replacing the fuse the powetubes started to glow again but this time without any sound. i was able to get some clean guitar Signal from the amp from CLEAN channels SEND EFFECTLoop (into my Laptop), but a very weak one (recorded it via Audio interface into my Laptop)
however the lead chanel didnt made any Sound , not even trough the EFFECT LOOP. at first i tought my cab was not wired properly but after measuring it with a multimeter it showed 14 ohms which is ok.

My question is . what is now broken in my amp? preamp tubes?if so what tubes do i Need to buy do i Need to buy a full set and get the bias adjusted?
any hints? reccomendations?

cheers
 

WillLane

Member
Messages
2,033
Hi
bought my amp a week ago used and was playing at moderate volume when suddenly my amp went completely off, a fuse blew and it went completely dark, after replacing the fuse the powetubes started to glow again but this time without any sound. i was able to get some clean guitar Signal from the amp from CLEAN channels SEND EFFECTLoop (into my Laptop), but a very weak one (recorded it via Audio interface into my Laptop)
however the lead chanel didnt made any Sound , not even trough the EFFECT LOOP. at first i tought my cab was not wired properly but after measuring it with a multimeter it showed 14 ohms which is ok.

My question is . what is now broken in my amp? preamp tubes?if so what tubes do i Need to buy do i Need to buy a full set and get the bias adjusted?
any hints? reccomendations?

cheers
Try plugging the guitar directly into the Effects RETURN input. If it works, that means your power section is working and one of your preamp tubes is unhappy.

Preamp tubes do not have to be matched. I would recommend just getting JJ's for the amp, maybe a Tungsol for V1 if you want to give the amp a bit of clarity. Power tubes need to be matched but you do not have to adjust the bias on the VK.
 

franz

Member
Messages
6
Try plugging the guitar directly into the Effects RETURN input. If it works, that means your power section is working and one of your preamp tubes is unhappy.

Preamp tubes do not have to be matched. I would recommend just getting JJ's for the amp, maybe a Tungsol for V1 if you want to give the amp a bit of clarity. Power tubes need to be matched but you do not have to adjust the bias on the VK.
tried the RETURNinput without any luck, and even checked the send Output for Signal but without any luck. turned out it that one power tube burnt(literally the glass is black from the inside)also a fuse inside the amp blew aswell f201. i will update once i get new fuses and power tubes.

when i got the amp it seemed like it was running quite hot, but i tought that was normal for a 100w head
thanks btw nice to know that i dont have to bias that Thing, i am getting some 6l6gc Rubys since they are cheap.

cheers
 

WillLane

Member
Messages
2,033
tried the RETURNinput without any luck, and even checked the send Output for Signal but without any luck. turned out it that one power tube burnt(literally the glass is black from the inside)also a fuse inside the amp blew aswell f201. i will update once i get new fuses and power tubes.

when i got the amp it seemed like it was running quite hot, but i tought that was normal for a 100w head
thanks btw nice to know that i dont have to bias that Thing, i am getting some 6l6gc Rubys since they are cheap.

cheers
Ok. Sorry you've had bad luck here. Make sure you are replacing the fuse with an exact match and that your power tubes are matched. While you are in the amp check the internal fuses as well. Be aware that there are lethal voltages inside amps even when they are off and unplugged. If you are not comfortable working around and draining those voltages, please just take the amp to a tech and save your life.
 




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