96 Tremoverb tube issue

Discussion area for Single, Dual and Trip Rectifers

Moderators: Guitarzan, Grandor, ned, Platypus

Post Reply
skydizzle
Mark I
Posts: 37
Joined: Sat Oct 19, 2013 7:53 am
Location: Wiesbaden, Germany

96 Tremoverb tube issue

Post by skydizzle » Sat Oct 17, 2015 5:39 am

Hey guys, a while back I picked up a tremoverb in a trade. When I got it, I plugged in and nothing. After i looked again, I noticed that one of the 6l6 and 5u4GB tubes had been mixed up. I saw the 5U4GB was burned, So I haven't tried the amp since then, because I wanted to check it over first. Well today I pulled the chassis out and found this. Notice the resistor is fried.
Image

So then I took a closer look at the tubes and found this. I'm not sure if you can see in the pic, but the tube is kind of black and burned.
Image

I also noticed the both of the 5U4GB tubes are different sizes, which I doubt would be an issue but just double checking. Anyone know?
Image

Other than the one resistor and tube, everything else looks good to go. Do you think if I swap the resistor for a new one, and get all new tubes everything will be ok?
PRS Custom 24
PRS CE22
PRS SE Tremonti
Fender Telecaster Plus
Ibanez GRG7221
Gibson LPJ
Epiphone Les Paul

Mesa Tremoverb
Peavey 6505
EVH 5150 III
Laney Ironheart
Carvin X100B
Marshall 1960B
Marshall 1960A
Randall R412CXM
Orange PPC412C

RR
Single Recto
Posts: 1719
Joined: Thu Jul 21, 2005 2:56 pm
Location: Pacific Coast

Re: 96 Tremoverb tube issue

Post by RR » Mon Oct 19, 2015 1:34 pm

You have a grid resistor failure. Not an unusual problem, common break down on any tube amp. A grid resistors could last a lifetime of the amp or could burn out anytime.

Get the value and try replacing it. Hopefully the burnt resistor was not cause by something else.

VladB
Bottle Rocket
Posts: 4
Joined: Tue Oct 20, 2015 3:29 pm

Re: 96 Tremoverb tube issue

Post by VladB » Tue Oct 20, 2015 3:31 pm

I had the same thing happen to my 2 channel Recto. It still works though :shock:

Do we know the value these are supposed to be?

skydizzle
Mark I
Posts: 37
Joined: Sat Oct 19, 2013 7:53 am
Location: Wiesbaden, Germany

Re: 96 Tremoverb tube issue

Post by skydizzle » Sat Oct 24, 2015 2:53 am

Hopefully it's just the grid resistor. That's an easy fix. The only thing that worries me is that when I play the sound fades in and out, almost like if the tremolo was on, even though it wasn't. Here is the schematic for the TOV for the grid resistor.
http://www.classictubeamps.com/schemati ... ematic.pdf
PRS Custom 24
PRS CE22
PRS SE Tremonti
Fender Telecaster Plus
Ibanez GRG7221
Gibson LPJ
Epiphone Les Paul

Mesa Tremoverb
Peavey 6505
EVH 5150 III
Laney Ironheart
Carvin X100B
Marshall 1960B
Marshall 1960A
Randall R412CXM
Orange PPC412C

afu
Mark IV
Posts: 662
Joined: Thu Aug 15, 2013 12:20 am
Location: Tucson, AZ
Contact:

Re: 96 Tremoverb tube issue

Post by afu » Sat Oct 24, 2015 8:04 am

Because the rectifier is a diode and the pins do not correlate whatsoever with a 6L6GC or other pentodes, the resistor burned because the heat exceeded its wattage rating. That same condition would burn the 5U4GB. This is actually a normal thing if those tubes are swapped. A new 5U4GB and a 1k/2W resistor should have you good to go, as long as the OT isn't messed up. I hope you got a great deal in this trade, because I'm pretty sure this low cost repair gets you a great amp.
2007 3 Channel Dual Recto w/loop mod

My Humble Music Tech Blog:
Dual Rectifier Index

skydizzle
Mark I
Posts: 37
Joined: Sat Oct 19, 2013 7:53 am
Location: Wiesbaden, Germany

Re: 96 Tremoverb tube issue

Post by skydizzle » Fri Oct 30, 2015 10:03 am

afu wrote:Because the rectifier is a diode and the pins do not correlate whatsoever with a 6L6GC or other pentodes, the resistor burned because the heat exceeded its wattage rating. That same condition would burn the 5U4GB. This is actually a normal thing if those tubes are swapped. A new 5U4GB and a 1k/2W resistor should have you good to go, as long as the OT isn't messed up. I hope you got a great deal in this trade, because I'm pretty sure this low cost repair gets you a great amp.
Yeah I have the parts on the way, so we will find out shortly haha. And yes I got a good deal. I traded a used 90s American Standard Strat for it, so I came out on top for sure.
PRS Custom 24
PRS CE22
PRS SE Tremonti
Fender Telecaster Plus
Ibanez GRG7221
Gibson LPJ
Epiphone Les Paul

Mesa Tremoverb
Peavey 6505
EVH 5150 III
Laney Ironheart
Carvin X100B
Marshall 1960B
Marshall 1960A
Randall R412CXM
Orange PPC412C

Post Reply