Tube socket on a Fender Super Reverb

[davebelcher98]

So, I have a late 60s/early 70s Fender Super Reverb that I've had for about 5 years now (the tube chart with the serial is rubbed off and torn just where the numbers are -- and I haven't opened the chassis to look at caps and transformers...my old tech told me that he was pretty sure it was a 68, and I know it's at least a 68 because it's silverface with push/pull master).

Anyway, I have an issue with my #2 power tube (farthest from input in the circuit): sometimes when I turn on the amp, the filaments of that tube don't fire up, or other times, when I am playing for a bit, that tube will kick off (I can hear a noticeable difference both in volume and in tone -- becomes very flubby) -- when I check the power tube, sure enough, the filaments aren't glowing, and it's cold. I know the tube itself is fine.

Is this most likely a bad tube socket, or do I have to expand my options to a possible bad place in the circuit connected to this output tube? As simple as a loose solder joint?

Thanks for any help!

dave b

[Papa Joe]

It might just need a good cleaning of the contacts or maybe a poor soldier joint.
Be sure to drain those caps before you touch anything on the inside,or be ready for the "shock of your life"...

[Wally]

Dave, you can go here.....
http://www.superchamp.dk/papers/dati..._tube_amps.htm
and find the year of manufacture of that amp using the serial number that is stamped in the rear panel of the chassis.
Papa Joe has given good advice. Since the other heater filaments are working, the probelm lies in the connection to the socket, the socket itself or....the tube, right?

[DH82c]

+1 for the tube of a loose pin on the socket. Easy to clean and tighten yourself IF YOU KNOW HOW TO DISCHARGE THE CAPS.

Mastervolume and Pull knob makes the super at least a mid 70s. or later.

[davebelcher98]

Hey thanks folks. I know enough about the dangers of the high power voltage in a tube amp to keep out of there for now. I mean, yes, I know what to do to drain the caps and to work with one hand behind my back, or even how to utilize a "bleed circuit" by flipping on the standby and such, but I generally decided that potentially receiving that kind of voltage with as little experience as I have is enough for me to stay out of there.

DH82c, I was told that the Master push/pull was installed first in '68....obviously I must be mistaken there. Is it rather that the Master was installed in 68 while the push/pull on the master was first utilized mid 70s??

Again, thanks for help with this.

peace,

dave b

[Raybob]

Originally Posted by davebelcher98

...sometimes when I turn on the amp, the filaments of that tube don't fire up, or other times, when I am playing for a bit, that tube will kick off (I can hear a noticeable difference both in volume and in tone -- becomes very flubby) -- when I check the power tube, sure enough, the filaments aren't glowing, and it's cold. I know the tube itself is fine.

Is this most likely a bad tube socket, or do I have to expand my options to a possible bad place in the circuit connected to this output tube? As simple as a loose solder joint?

Try spraying the pins of the tube with contact cleaner and run the tube in and out a few times. If the tube goes in real easily, you might need to tighten the prongs inside the socket. Be sure to discharge before sticking metal objects in that socket. If that doesn't do it, the solder joints at pins 2 and 7 need to be re-flowed.

[PhatTele]

It's not a 68 (drip edge era). It might be a 69, but it's more likely a 70s. Whatever it is, given that it's in that era, it will have the bias balance system...not what you would find in the 68 or BF era versions. I'm wondering if the problem might be due to that setup. Maybe one tube is horribly underbiased relative to the other and is just dying out. Has it ever been serviced?

[Wally]

Dave, if you have checked the serial number against that info on the site to which I linked you; then you will know that that SR is from no earlier than the mid-'70's. The push/pull MV is the giveaway there. IF you read 70 watts under the speaker jack, then it is an ultra-linear model from 'the late '70's.

[davebelcher98]

Sorry for the silence folks! I've been out of town and busy...

Yeah, based on the serial system Wally linked to, this is a 1978. The last time I had this thing serviced, I payed way too much to have someone basically change out the power tubes, do a bit of cleaning, and put a three-pronged plug on wall plug. That was about it. If only I knew better then!

Well, I'm moving out to North Carolina in about a month, and I'm hoping to take this out to a really knowledgeable tech who does fantastic work out there (in Raleigh/Durham). Hopefully that can easily solve my problems since I'm still a bit leary of getting in that chassis, even knowing the safety procedures. Thanks again.

dave b

[Wally]

Okay, DAve, so you have a 75 watt Ultra Linear SR there.
Good luck with the move and a new tech. IME, that amp could do with new electrolytics.
The problem yo uare having with that one tube should not be too major in itself. A new socket or tube/s woudl be themost expensive possibility.

[davebelcher98]

Thanks Wally. I can say confidently that regardless of the year on this thing (man folks sure do beat up on the silverface's sometimes), to my ears this is one fine amp...I love it. Wouldn't play anything else (and I've played a lot!!).

And the dude I talked to in Raleigh, NC -- his name is Darren Riley, probably familiar to a lot of folks here because he is the man when it comes to getting folks all sorts of parts at a good price and quick! -- he should be able to take a look at the amp once I get down there in about a month. I'll probably have him retube it, fix that socket (or tube, or solder joint, or what have you), and yes, probably replace those old filter caps! I bet they're starting to ooze by now!

Peace,

dave b

[scoots]

i have a deville 212 and have just gone through the same symptoms to a "T"! prognosis---yup, loose solder joints to the power tube. had it resoldered and haven't had a problem

[mellecaster]

Originally Posted by davebelcher98

Thanks Wally. I can say confidently that regardless of the year on this thing (man folks sure do beat up on the silverface's sometimes), to my ears this is one fine amp...I love it. Wouldn't play anything else (and I've played a lot!!).

And the dude I talked to in Raleigh, NC -- his name is Darren Riley, probably familiar to a lot of folks here because he is the man when it comes to getting folks all sorts of parts at a good price and quick! -- he should be able to take a look at the amp once I get down there in about a month. I'll probably have him retube it, fix that socket (or tube, or solder joint, or what have you), and yes, probably replace those old filter caps! I bet they're starting to ooze by now!

Peace,

dave b

You have made an Excellent choice in using Darren IMO....I have looked inside of Amps he has worked on, and he does neat Professional work, and is a Great Guy.