Kev-wilson
Tele-Meister
I'm a learner so I'm likely wrong, but the jack to the left if grounded to the chassis, wouldn't the switch be grounding your output from the speaker jack?
First amp build, tweed deluxe 5e3, not working!
- Thread starter Duelling Banjo
- Start date
zeppelinofled69
Tele-Holic
Not in this case. He doesn't have a the switch on the second jack connected to ground.
O.P. Have you checked the switch on the output jack to make sure that it is disconnecting when the speaker plug is inserted? It'll push the tip connector away from the switch connector just enough to break the connection to the switch tab.
FXBDM 1832
Tele-Meister
Have you tried the pop test mentioned upthread?
If amp has a tube rectifier or HV/stby switch control positive HV DC it take about ten minutes to test OT, speaker jack and loudspeaker!
Detach Mains plug, select Mains and HV switches Off. This order is better when operating amp use current from capacitors but this can not be trust because amp can be faulty. Therefore measure that main electryte does not have charged voltage and if there is then discharge electrolytes.
Remove rectifier tube and power tubes. Take two short pieces of wire, bend them U-shape and push power tube sockets pins 2 and 3 on other socket and 7 and 3. If wire is very thin fold and wound its ends so that they connect with socket. Insert Mains plug and switch Mains power switch On. This connect filament AC to OT primary ends and Mains frequency can be heard from loudspeaker
If you don't hear there is a possibility that U-vires feed same filament phase to OT so either measure that there is about 6,5VAC on U-wires and/or change other wire end between 2/7 on other socket. If still no Mains buzz sound there is something wrong on OT, jack or loudspesker circuit or there is no needed filament voltage on power tube sockets.
Duelling Banjo
TDPRI Member
It's correct as per the wiring diagram but thanks all the same for the suggestion
Duelling Banjo
TDPRI Member
Thanks @2L man your advice to work on the speaker out section seems to have solved the problem, amp is now working !!! 
I was initially confident of that bit because the cable I had taken off an extension cab for a different amp and knew it to be working. So I wired up a spare speaker as you suggested, but no difference. Ok, at least I tried. Then plugged the lead back in and bingo! So must have been a dodgy connection between the jack plug and socket or something along those lines. I'm gonna install it into the cabinet later, then give it a good play to see if it sounds ok and to check whether or not there is any intermittent problem. If there is at least I know where to go looking for it.
Thanks also to everyone else who took the time look at the pictures and give there advice. Very much appreciated. I'll give you an update once the amp is fully complete and tested.
I was initially confident of that bit because the cable I had taken off an extension cab for a different amp and knew it to be working. So I wired up a spare speaker as you suggested, but no difference. Ok, at least I tried. Then plugged the lead back in and bingo! So must have been a dodgy connection between the jack plug and socket or something along those lines. I'm gonna install it into the cabinet later, then give it a good play to see if it sounds ok and to check whether or not there is any intermittent problem. If there is at least I know where to go looking for it.
Thanks also to everyone else who took the time look at the pictures and give there advice. Very much appreciated. I'll give you an update once the amp is fully complete and tested.
Lowerleftcoast
Poster Extraordinaire
Glad to hear it is working.
This *open* switch doesn't look any different than the *closed* ext. jack switch from this angle. Make sure it actually breaks the connection when a plug is inserted.
If it is too close when open, do not bend the switch part. Bend the tip part at or near the curved section. It only needs to open about the thickness of a dollar bill or so. Be gentle, if you decide to perform this kind of fix.
This *open* switch doesn't look any different than the *closed* ext. jack switch from this angle. Make sure it actually breaks the connection when a plug is inserted.
If it is too close when open, do not bend the switch part. Bend the tip part at or near the curved section. It only needs to open about the thickness of a dollar bill or so. Be gentle, if you decide to perform this kind of fix.
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Also, and this may be stupid, but: Are you sure your output jack is securely grounded? There are two ways to do this: 1) traditional, that is the jack is just grounded to the chassis mechanically (sleeve, bushing & washer/nut contact the hole through the chassis), or 2) Blencowe-style purist: isolate the jack(s) from chassis locally using plastic and/or phenolic washers, and run a ground wire from jacks to the ground bus.
I have to second @Lowerleftcoast's observation about the tip switch looking closed in the jacks photo, despite the plug being inserted.
I have to second @Lowerleftcoast's observation about the tip switch looking closed in the jacks photo, despite the plug being inserted.
I may have missed something. Is there anything that makes you think the (extremely common) first method isn’t in play there, or might not be secure?
LLC's bent switch prong is common, I’ll admit, and is good to check, but IME visual inspection from the angle of the photo isn’t very helpful. I'll wait to hear from Dueling Banjo whether both switches are both opening and closing correctly.
No, not at all; just thought I'd mention the other approach in the time-honored tradition of TMI. It is possible, however, that a loose mechanical connection to chassis is in play, no?
I'm no expert, but I'll just throw this one out. Neutrik plug going into an open-frame (not Neutrik) jack sourced from Europe. I personally have had trouble with open-frame jacks that weren't Switchcraft (detent/contact for the tip being not far enough or too far from the plug tip when seated). So I'm Switchcraft all the way now (OK, G&H for phone plugs too). I'd say, check & double-check the fit of plug and jack.
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Duelling Banjo
TDPRI Member
Here's my chassis mounted in my re-purposed and previously non-functioning Blues Junior combo. I hope I haven't committed sacrilege, but my motive was that I didn't want to chuck the BJ and I really fancied a tweed deluxe at a bargain price. Still haven't had time to give it a thorough workout so I'm taking on board the much appreciated comments above and will get into them more deeply if there are any problems going forward.
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dan40
Friend of Leo's
@Duelling Banjo...Glad you got the amp working. I noticed in your pic of the speaker jacks that the solder connections on the main jack don't look like they flowed out and properly wetted the solder tab. This is known as a "cold joint" and you can recognize it when the solder looks lumpy and balled up instead of flowing out smoothly like the joints on the aux jack. It would be wise to reheat them and flow the solder out a bit more to ensure that you have a solid electrical connection. A bad connection here can cause low volume or no volume but more importantly, it can blow your OT if it loses connection while playing the amp.
Edit: I also noticed that you used standard, stranded copper wire in the build. This will work fine but it can be hard to achieve good solder joints unless you pre-tin the end of the wires before soldering them. This wire that I linked to below, comes pre-tinned and holds it's shape almost as well as solid core wire. It's also much easier to insert the stripped end into solder connections because the wire doesn't fray and separate when you try to insert it.
Edit: I also noticed that you used standard, stranded copper wire in the build. This will work fine but it can be hard to achieve good solder joints unless you pre-tin the end of the wires before soldering them. This wire that I linked to below, comes pre-tinned and holds it's shape almost as well as solid core wire. It's also much easier to insert the stripped end into solder connections because the wire doesn't fray and separate when you try to insert it.
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Uh, I was just looking at @Duelling Banjo's photo of his jack situation, and noticed that there's a hair that seems to bridge between sleeve and the tip lug (on the right side of the main speaker jack). Could that have been the problem?
Duelling Banjo
TDPRI Member
Thanks @dan40 I'll double check the solder connections though they feel pretty solid and the amp is working now. Don't forget I bought this as a kit so I used the included wire and I did tin the ends of most of the wires before soldering them.
Haha, well observed @chas.wahl I only noticed that myself when I saw the photo, my phone records more detail than my eyes. I subsequently removed the hair with a pair of tweezers and a magnifying glass though that didn't fix the problem at that point. Now you mention it, does a human hair conduct electricity?
Not lethally because there are alive rock musicians but no doubt it must have some effect to brain function
Heh, I was puzzled as to why our crack detectives were still looking for a problem after you got your amp "fixed," but when I re-read this, I get the feeling that though *something* changed at the jack/plug connection, we don't know what. Am I right?
If it wasn't a wild hare or stray hair,
it does suggest our crime squad's concern about the switch prong(s) could be the problem. Can you confirm they open visually, and close firmly to the tip prong, when a plug is inserted and removed? If that's not it, was it actually the *plug* wiring/soldering? Or was it possibly the soldering to the jacks? The jacks' contact to the chassis? It's been mentioned that some plug sleeves are a little smaller than the jacks they plug into, which I've seen cause a dodgy connection. Are both your plugs and your jacks actual Switchcraft/Littlejack items?
Ah, right, good eye. FWIW I have a couple Neutrik plugs and they fit snugly in Switchcraft jacks.
Elwood Telly
TDPRI Member
Why not? It seems to fit well and Blues Junior is with 12" already - it makes a nice combo with mainly less of width.
I owned Blues Junior (mark III) once, it was quite okay with little mods - i.e. proper pair of EL84's and 12AY7 in pre-amp + Emincence 35 W alnico. My Deluxe is a head version in Mojotone's cab and I keep swapping cabinets between 2x10" WGS Veterans and 1x15" Jensen C15K.
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