nukaidee said:
Those sockets should have come with brackets, though you won't be able to use them as bottom-mount now that they are soldered down. To take the strain off of the top of the eyelet on the PCB, you can heat the hole from the back and insert a piece of solid wire until it pokes through the other side (preferably through the loop on the socket tab). Then trim the wire flush to the back of the PCB.
the wires I will install with the "poke through" method, actually I might have screw terminals on the way ^_^. yeah the sockets came with brackets, never figured out how they worked and most peoples don't have them? so i just left them out
well.. the amp is finally built! unfortunately no pictures yet. I have a little bit of hum, but other than that it sounds good! after about an hour of listening it just turned off =( I'm suspecting its the 5ar4. I have another one, but before I throw it in there, is there someway I can lower the voltage so I don't pop another? Seems like all the tubes are running quite warm, but I'm not sure whats the right temperature. The glow is uniform and doesn't seem too bight.
so anyways. update! apparently one of my 2 fuses blew. I guess 2A isn't enough? I'm in Canada so its 110V. Should I move up to a 3A sloblow?
No, don't move up to a 3A fuse. Something went wrong blew the fuse. You need to figure out what it was.
do you have any suggestions to begin testing? I wasn't pushing it hard at all, and like I mentioned, everything seemed normal, sound, heat, and lights. Its my first tube amp so I'm kind of stumped.
Blown fuse is due to a short somewhere. Using the ohmmeter is probably the best way to find it.
Likely causes are the two caps in the power supply (C1 or C2), the two FRED diodes (D1 or D2), an arc in the rectifier or power tube, or a mistake somewhere in the assembly (strand of wire got loose from a Phoenix connector, or solder bridge).
Likely causes are the two caps in the power supply (C1 or C2), the two FRED diodes (D1 or D2), an arc in the rectifier or power tube, or a mistake somewhere in the assembly (strand of wire got loose from a Phoenix connector, or solder bridge).
but wouldn't shorts cause blown fuses instantly instead of over an hour later? The only rectifier is the tube. I will check over the phoenix connectors first then I guess. The solder joints are okay. I just double checked them. I'm used to soldering SMD.. I think I might need more solder on some parts too
just checked them all. no shorts in the phoenix connectors.. the capacitors seem normal too. will a short in the outputs cause the fuse to blow? its the fuse on the live line before the power transformer that blew
If you used the IXYS FRED diodes listed in the parts list, they have likely failed. They fail at random times and it doesn't matter if you are using the tube rectifier or not. If you are using them, I would take them out for starters. They are not needed in the SSE if you are using the tube rectifier.
Yep. I never even bought them. It was always the tube rectifier from the start. oh. dont know if this helps, but when i first powered up there was a bit of static that came through the system until the tube actually warmed up / powered on.. approx 5-10 seconds?
generic chinese 5ar4. the tube is fine. I threw in another 2A fuse and it starts and plays well. I just turned it off after 10 minutes.. I dont feel like blowing another fuse.. the cost adds up.. still trying to find the cause of it. Its already a sloblow. there is no way i need a bigger one right?
I tried a different 5ar4. it still glows the same. only have ran it for about 30min. doesn't seem to be any difference
Well, its been half a year since its played 30 min of music. I've checked all my connections on and off. now I have 2 weeks of time off and I plan to get this going for good. Can someone be kind enough to guide me in the right direction? What should the ideal voltages be and where should I be prodding?
I went back and re-read through the whole thread. I'm worried about the way you "surface-mounted" the tube sockets. It seems like it would be all too easy for a trace to get lifted from the board, and open a critical connection. Even worse, it might be the sort of thing where it only happens once the amp starts to get hot and things begin to expand. Maybe after it has been running for 30 minutes or so...?
Someone suggested you go back and reinforce the socket-to-board connection by fishing short (3/8"?) bits of wire through the holes in the PCB, and folding the wire over the leg of the socket. I wonder if that would be a good idea, or if it would just make a bigger mess of things?
Someone suggested you go back and reinforce the socket-to-board connection by fishing short (3/8"?) bits of wire through the holes in the PCB, and folding the wire over the leg of the socket. I wonder if that would be a good idea, or if it would just make a bigger mess of things?
I was worried about the sockets as well. I let the amp run on low volume again until the fuse blew. It was approximately the same time. 35 minutes. Then I checked the connections with an ohmeter. all the sockets connect to their respective "neighbor" component with 0 resistance.
*thanks for your help. I know its tedious but I will never succeed without your efforts too
*thanks for your help. I know its tedious but I will never succeed without your efforts too
Hmm. If it blows the fuse after half an hour, it must be something thermal related. Something is moving after it gets hot, and that causes the problem. Can you post some photos of your completed assembly, including whatever chassis work you did?
If the amp is "working fine" for the first half hour, then I'll assume your construction is correct. Still, it might not hurt to carefully check for "normal" operating voltages. Always remember there are lethal voltages on the board when it is operating. Keep one hand behind your back, and use probe clips where appropriate. There ought to be a voltage troubleshooting table somewhere, but I can't say if I've ever seen one for the Simple SE. The usual places to check would be around the power supply (two L1 terminals, R14), around the power tubes (plates, screens, cathodes), and around the driver tube (plates, cathodes).
I'm trying to think if there is some way to isolate just the power transformer, and test it. I'd hate to think your PT has a bad spot in the insulation that is causing a short once the windings get hot. I don't suppose you happen to have any 60 watt, 750 volt light bulbs around?
Something to keep in mind is that you don't want to exceed the maximum working voltage rating of the power supply caps (C1 & C2) for any prolonged length of time. If you choose to do any kind of testing with the power tubes unplugged, the voltage of the unloaded power supply will likely exceed 500 VDC. Try to keep this kind of testing as short as reasonably possible.
Something else to keep in mind is that many tubes don't like to have their cathodes "baked". That is to say the heater voltage is applied (5V or 6.3V) for a prolonged period of time without applying any high voltage B+ at the anodes. It might occur to you to try to test the filament windings of the PT by simply disconnecting the HV winding (probably the red wires) and carefully taping off the bare ends. You could leave it running this way for a while and see if the fuse blows, but I wouldn't leave it like that for hours and hours. It might not prove anything anyway - with no B+, there's about 40 watts of heat that's not going to be generated in the amp.
If the amp is "working fine" for the first half hour, then I'll assume your construction is correct. Still, it might not hurt to carefully check for "normal" operating voltages. Always remember there are lethal voltages on the board when it is operating. Keep one hand behind your back, and use probe clips where appropriate. There ought to be a voltage troubleshooting table somewhere, but I can't say if I've ever seen one for the Simple SE. The usual places to check would be around the power supply (two L1 terminals, R14), around the power tubes (plates, screens, cathodes), and around the driver tube (plates, cathodes).
I'm trying to think if there is some way to isolate just the power transformer, and test it. I'd hate to think your PT has a bad spot in the insulation that is causing a short once the windings get hot. I don't suppose you happen to have any 60 watt, 750 volt light bulbs around?
Something to keep in mind is that you don't want to exceed the maximum working voltage rating of the power supply caps (C1 & C2) for any prolonged length of time. If you choose to do any kind of testing with the power tubes unplugged, the voltage of the unloaded power supply will likely exceed 500 VDC. Try to keep this kind of testing as short as reasonably possible.
Something else to keep in mind is that many tubes don't like to have their cathodes "baked". That is to say the heater voltage is applied (5V or 6.3V) for a prolonged period of time without applying any high voltage B+ at the anodes. It might occur to you to try to test the filament windings of the PT by simply disconnecting the HV winding (probably the red wires) and carefully taping off the bare ends. You could leave it running this way for a while and see if the fuse blows, but I wouldn't leave it like that for hours and hours. It might not prove anything anyway - with no B+, there's about 40 watts of heat that's not going to be generated in the amp.
My temperature readings seem okay to me, they feel the same as my friend's "melody" kt88 amp. I will give those voltages a check when I get home tonight. I definetly don't have any 750 volt light bulbs around.. maybe I'll need to serial 6 of them together? My power caps are rated to 750 so I'm not too worried.
I'm not too sure what you mean about the cathode baking as this would be resolved by swapping different tubes correct?
I'm not too sure what you mean about the cathode baking as this would be resolved by swapping different tubes correct?
If the cost of fuses is getting you down, try looking for an Allen Bradley 1492-GH-015 circuit breaker. It's rated for 1.5 amps. It snap mounts onto DIN rail, but you could probably find alternative ways to mount it.
I've seen them on eBay for under ten bucks.
Allen Bradley Circuit Breaker 1492-GH-015 Series B 1.5A - eBay (item 160379715401 end time Jan-18-10 10:03:48 PST)
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