Dead Twin...

Steve Hinson · Post by **Steve Hinson** » 3 Apr 2003 3:40 am

I use a Twin head in the studio...it worked great all day Tuesday.Wednesday morning dead as a doornail-no sound,none of the tubes light up,nothing-but the pilot light comes on!Can one of you amp guys tell me what to check out?I used to fool with amps a lot,but this one has me stumped!Thanks-Steve

Bill Crook · Post by **Bill Crook** » 3 Apr 2003 5:37 am

Steve.....

If you wish to bring your amp by my house, I will help you check it out. Between the two of us, I'm sure we can find your problem. As I am retired,I really don't need $$$$ to help a "Steel" friend. We'll figure out whats wrong and then you can fix it yourself (should you wish to).

Give me a call at (615) 865-6579

C Dixon · Post by **C Dixon** » 3 Apr 2003 7:05 am

Steve,

It has been over 30 yrs since I last touched an amp, so I may be way off base. But it seems to me that I recall the "filament" voltage for all the tubes (lighting up) is the same source that is used for the pilot light.

If this is the case, it would appear to be a broken wire (possibly from heat over time) between the pilot light socket and the wires that connect each tubes filament pins. Also, if my memory serves me correctly, the filament pins are always on either side of the "key" (cutout) in the power tubes' sockets.

You may wish to take a volt-ohmeter, set it for AC readings and check first the voltage at the pilot light socket (as a reference); and then see if you have this same voltage at those pins mentioned above at the power tube sockets' filament pins. It should be 6.3V AC.

If not, you can trace those specific wires back to the pilot light socket and you may find a break.

Again, I am runnin on 71 yr old memory cells and they are failing I am sure.

God bless you in your quests,

carl

Vernon Hester · Post by **Vernon Hester** » 3 Apr 2003 12:38 pm

Check the B+ on the plates of the 6L6's If OK
check the Screens of the tubes, Those resisters go out on those amps. If no B+ Check the toogle switch and then the rectifer
doides.

Bill Terry · Post by **Bill Terry** » 3 Apr 2003 2:14 pm

Check the B+ on the plates of the 6L6's...

Be very careful Steve...

Steve Hinson · Post by **Steve Hinson** » 3 Apr 2003 3:18 pm

Well,after I posted this morning,and drank enough coffee to wake up enough to keep from being electrocuted,I started fooling with the amp...I took the chassis out and started poking around the wires with a Sharpie(no metal)and finally got some sound out of it...took about 5 seconds.I think one of the wires must have just about unsoldered itself from sheer heat(this amp gets REAL hot)...Carl,if I hadn't found it this morning,I think I would have after reading your post!Thanks to everyone!PS-Bill Terry-I ain't scared...I've been a member of the 400 Volt Club for about 20 years...

Ken Fox · Post by **Ken Fox** » 3 Apr 2003 4:06 pm

Steve, I had a Super Reverb (1967) that had this problem on the first two preamp tubes. The wire had actually broken at tube #3 pin. It was intermittent, wire was laying right up against the pin of the tube socket. You may have this happen to you again. A little more poking and pulling on the wires might reveal a break or cold solder joint. The heaters go from the power tubes first then on to each of the preamp/driver tubes. A break at one tube will put out the lights of the other ones down the line from it. If all the tubes were out, then message #3 above is right on the money! [This message was edited by Ken Fox on 03 April 2003 at 04:08 PM.]

Jerry Erickson · Post by **Jerry Erickson** » 3 Apr 2003 4:40 pm

And don't forget to discharge the filter caps!

Steve Hinson · Post by **Steve Hinson** » 3 Apr 2003 6:25 pm

I found the loose wire while ago...resoldered it...good as new...thanks guys!

Steve Hinson · Post by **Steve Hinson** » 9 Apr 2003 3:56 am

...and thank you,Bill Crook,for your most gracious offer...