#1
Ok, so I was just playin a few minutes ago on my Fender Twin Reverb. First off my Reverb went out a while ago and I still have to get a new pan I think, I've tried cleaning the contacts but it still doesnt work, but for some reason the Vibrato still works, So if you have any additional things I could do to get that reverb working I would appreciate it.

Also, when I was playin my amp just cut of the sound, I was playin for a bout 30 minutes not real loud or anything, and then it just stopped out of nowhere. Also the other day when I turned it on I didnt get sound for like 5 minutes. I dont know why, please help!
#3
Oh and now to get sound back after this incident I had to turn the volume way up and strum the guitar. And then I was playin a little more and the sound started cuttin out, but when i turned the volume up it seemed ok. Man this is a bummer
#6
I don't think the reverb pan does anything at all for the vibrato circuit, could be wrong though. The reverb tube is the most likely issue with it. Have you changed that tube? How old is the amp?

Like 311 asked, are you sure your cords/cables are good? The crackling in and out sounds like a cord issue. Have you performed a re-tube on the amp yet?

EDIT: OK, looking at the back of the amp you should have 3 smaller tubes hanging down on the right side. (Under silver covers that need to be removed. Push up slightly on the cover and turn clockwise then pull down gently. That should get the cover off. I am away from home so I may be off on the direction - BE CAREFUL). The second and third inwards, towards the center of the amp should be 12AT7's. These drive the reverb and vibrato respectively. You should be able to swap them and see if the reverb comes back. They only go in one way so be careful, they pull straight down and push straight up - but will only line up one way. It should kill the vibrato if the tube is bad. Have the amp unplugged and cool when you do this.
Last edited by gregs1020 at Oct 10, 2008,
#7
I tried some things from that thread yes, Im not sure if one of my tubes run the reverb though, I couldnt find that information. And the day when I turned it on and it didnt give me sound for like 5 minutes I tried plugging straight in to my guitar, then into my pedals, then with a different cord. None of it worked. And when ever the amp was on and I pulled out the cable there was no sound (you know the sound of just pulling it out when its on..). But man I dont know what else I could do. I would take it to get looked at because I still have a warranty on it, but the closest place to my house is like almost 2 hours. And i'd have a week to do it before the warranty is over.

And by the way, thanks man for being concerned and trying to help me out, it really means alot!
#9
Read my edit two posts up. I explained how to swap the vibrato and reverb tubes to test and see if it is a tube. Both are the only 12at7's in the amp. 12at7 should be printed on the tubes. They are interchangeable.

Edit: So is it just the reverb or is the entire amp dead? If the entire amp is dead, have you checked the fuses?
#10
the amp works, it just goes out sometimes, and its only the reverb thats out, so ill try the tube switch now
#12
One thing that has been notoriously bad is the cheap ass speaker plug that goes from the speaker leads and plugs into the back of the amp. It's a regular 1/4 in jack. Once it "dies" try pushing on the plug as if it weren't all the way in. (Don't unplug it with the amp on). See what happens when you push on it. I had to replace my plug on my amp which is very similar to yours. (Was really glad it wasn't the actual jack). But that got the sound back, which is no help in the middle of a song while at a gig and it craps on you.

Edit:
#13
ok so i took the covers off of the 3 small tubes on the very right, the 2 furthest on the right have a red design on it that says fender and the 3rd onemore towards the center has a white design that says fender, so am i switching the 2 red or the red and white? and also there are 3 more smaller tubes in the center of the amp and then 4 big ones on the left, i dont touch those right?

Edit: the 2 on the very right are 12ax7A and the 3rd more toware the center is 12at7

Edit2: The list of tubes from left to right are like this 4 6L6-GCs, 1 12at7, 2 12ax7A, 1 12at7, 2 12ax7A
Last edited by galbracht at Oct 10, 2008,
#14
Just focus on the 3 rightmost tubes. According to this, http://www.fender.com/support/manuals/pdfs/manuals_elec/guitarpdf/65_Twin_Reverb.pdf your owners manual there are only 2 - 12at7s. Pull the second tube in from the right, see if it is a 12at7, then pull the third tube in and see if it is. I believe those are the two you need but I am trying to find a good diagram to post. Pull those two and see what cha got. I'll find a chart.

Edit: OK, hang on.
#15
Quote by galbracht



Edit: the 2 on the very right are 12ax7A and the 3rd more toware the center is 12at7

Edit2: The list of tubes from left to right are like this 4 6L6-GCs, 1 12at7, 2 12ax7A, 1 12at7, 2 12ax7A

According to your owners manual you should have 2 - 12at7's... Try swapping the second and third in from the right and test. It won't hurt anything if you only try it for a brief time. See if that works. I suspect you have a 12ax7a where a 12at7 belongs. Which may have caused it to blow, not positive that it would blow but it could.

Edit: Did you buy this amp used?

Edit 2: ok, I found this. http://www.unixhub.com/pics/fender/fender-Pages/Image10.html
And I'm think the first and second in from the right.
Last edited by gregs1020 at Oct 10, 2008,
#16
so switch the 12ax7a with the 12at7?

Edit: There is a small white diagram, and it shows the tubes with the names and power, and it is setup right though. It says it should go like i stated above
Last edited by galbracht at Oct 10, 2008,
#17
Read my second edit in the above post. Found a better look at the back. I think your 12ax7a's on the right are reverb and vibrato. Try that first.
#19
Go ahead and swap the two rightmost 12ax7a's as you are looking at the back of the amp. Plug the amp in, turn on and crank reverb. Come back and post results.
#20
Quote by galbracht
so switch the 2 tubes furthest on the right (the two 12ax7a's)?
Yup. But have the amp unplugged when you do it. Once swapped, plug er in and see what happens. You should be fine, the vibrato should be non functional if that tube is toast.
Edit: And the reverb should be godly...
Edit 2 - Back in 5 min.
Last edited by gregs1020 at Oct 10, 2008,
#21
Ok real quick, I unscrewed the thing holding the tube up, but how do i get it out?
#25
I dont get it, Im pulling but its not coming, Do i unscrew the silver part holding the tube up and then pull or leave it screwed in, I unscrewed it and tryed pulling down on the silver part and the glass part.And do I have to pull hard, cause I dont wanna break the tube :/
#26
It should come straight down once you have the cover off. Slight wiggle, very slight wiggle but pull straight down. It's like a baby light bulb but is sturdier than a light bulb.
I believe the nut you unscrewed holds the tube socket onto the board, so put that back.
Edit: The only thing holding the tube in is the pins on the bottom of the tube as in the pic above. Nothing holds a 12ax7a tube but those pins. The "shield" is there to protect the tube and dissipate heat.
Last edited by gregs1020 at Oct 10, 2008,
#28
Try a slight, slight wiggle while pulling down. Use and heat probably has it in there good.

Edit: ^ good, swap em and lets see if it's the tube.

Edit 2: I hope your enjoying reverb right now...
Last edited by gregs1020 at Oct 10, 2008,
#29
ok good news, 1st off- the problem with it cutting out was that speaker cable, when i pushed it in and moved it, it worked, but the reverb was not a success
#30
Quote by galbracht
ok good news, 1st off- the problem with it cutting out was that speaker cable, when i pushed it in and moved it, it worked, but the reverb was not a success

OK, we're half way there. I had the same issue with my fender and that plug from the speakers. I replaced the cord from the speakers to the jack on the back of the amp and have not had the issue since.

Out of curiosity - after swapping tubes did the vibrato continue to work? I'm thinking that you may have loosened the connection to the reverb tank by putting pedals in the back of the amp. They could have pulled on the wires. Is everything good there, connection wise to the tank?
#31
Is the tank the pan? And Yeah the vibrato still worked. Man, Thank you guys so much for stickin through this with me, really!

Edit: I was check through some stuff and saw this. "The Reverb control is used to control how much signal is sent to the two-spring reverb. One half of a 12AT7 is used for the reverb driver while one half of a 12AX7 is used for the reverb return, both tubes are dual triodes. ", Does that mean the reverb uses the 12at7 too. So what if its that tube?
Last edited by galbracht at Oct 10, 2008,
#32
Dude it's what we are here for. Replace that cord from the speaker to the jack. It may continue to "sputter" on you if you don't. That is what mine did. (I made one for like $6 bucks at Radio Shack).

Yes, the pan and the tank are the same thing. Something may have pulled on the wires connecting to the pan or the amp up top. Make sure it's unplugged please first!
#33
yes reverb tank/pan.

glad to see you got the immediate need taken care of. Hats of the Gregs

you've already cleaned the contacts as suggested and I think I gave you a link so some accutronics stuff in that other link but IS THIS REVERB TUBE DRIVEN? I seriously doubt it is the tank itself.
#34
Wait, So what should I do? Take the tank out and just push in all the slot and plugs?
#35


Well the reverb has a tube in the circuit, whether it "drives" the tank or molds the sound I'm ignorant to. But if the tube was blown it wouldn't have worked.

I tried a new DRRI recently and the vibrato didn't work. lespaul#1 got a DRRI new recently and the one in the store had broken reverb. Since the TS's amp is relatively new - I think it's something with Fender's QC. Mine was built in 1990 and I had the same speaker cord issue. Nothing since but tonal bliss but

TS - I realize you are 2 hours from the store, but if it isn't the tube and the connections look fine, I'm stumped.
#36
YESSSS, I cleaned the contacts, push a few things in the tank a little hard and BAM reverb. Thanks so much guys, you seriously just made my night. I have to work at 6 in the morning tomorrow and its 1030, I probably wont get to bed till 12 now haha or later!! Thanks again so much. One last thing, Where can I buy a better speaker plug, how much are they, and can i put it in myself?
#37
I got mine at Radio Shack, but you can order one through Fender. Mine was like $6 bucks. It's just a 1/4 jack with two plugs crimped on that plug onto the speaker. Nothing special to it really. If you can pull a tube and fix a tank, you're going to be fine with this.

Glad it's fixed, that's great news! Nice amp btw. Check your profile for a friend request or two. Enjoy bro!
#39
Thanks guys, and I just noticed I have messages from PM's, I never noticed them, and ones from you 311 lol. Thanks guys, I owe you one.